Support
Getting support for OpenShift Container Platform
Abstract
Chapter 1. Support overview
Red Hat offers cluster administrators tools for gathering data for your cluster, monitoring, and troubleshooting.
1.1. Get support
Get support: Visit the Red Hat Customer Portal to review knowledge base articles, submit a support case, and review additional product documentation and resources.
1.2. Remote health monitoring issues
Remote health monitoring issues: OpenShift Container Platform collects telemetry and configuration data about your cluster and reports it to Red Hat by using the Telemeter Client and the Insights Operator. Red Hat uses this data to understand and resolve issues in connected cluster. Similar to connected clusters, you can Use remote health monitoring in a restricted network. OpenShift Container Platform collects data and monitors health using the following:
Telemetry: The Telemetry Client gathers and uploads the metrics values to Red Hat every four minutes and thirty seconds. Red Hat uses this data to:
- Monitor the clusters.
- Roll out OpenShift Container Platform upgrades.
- Improve the upgrade experience.
Insight Operator: By default, OpenShift Container Platform installs and enables the Insight Operator, which reports configuration and component failure status every two hours. The Insight Operator helps to:
- Identify potential cluster issues proactively.
- Provide a solution and preventive action in Red Hat OpenShift Cluster Manager.
You can Review telemetry information.
If you have enabled remote health reporting, Use Insights to identify issues. You can optionally disable remote health reporting.
1.3. Gather data about your cluster
Gather data about your cluster: Red Hat recommends gathering your debugging information when opening a support case. This helps Red Hat Support to perform a root cause analysis. A cluster administrator can use the following to gather data about your cluster:
-
The must-gather tool: Use the
must-gather
tool to collect information about your cluster and to debug the issues. -
sosreport: Use the
sosreport
tool to collect configuration details, system information, and diagnostic data for debugging purposes. - Cluster ID: Obtain the unique identifier for your cluster, when providing information to Red Hat Support.
-
Bootstrap node journal logs: Gather
bootkube.service
journald
unit logs and container logs from the bootstrap node to troubleshoot bootstrap-related issues. -
Cluster node journal logs: Gather
journald
unit logs and logs within/var/log
on individual cluster nodes to troubleshoot node-related issues. - A network trace: Provide a network packet trace from a specific OpenShift Container Platform cluster node or a container to Red Hat Support to help troubleshoot network-related issues.
-
Diagnostic data: Use the
redhat-support-tool
command to gather(?) diagnostic data about your cluster.
1.4. Troubleshooting issues
A cluster administrator can monitor and troubleshoot the following OpenShift Container Platform component issues:
Installation issues: OpenShift Container Platform installation proceeds through various stages. You can perform the following:
- Monitor the installation stages.
- Determine at which stage installation issues occur.
- Investigate multiple installation issues.
- Gather logs from a failed installation.
Node issues: A cluster administrator can verify and troubleshoot node-related issues by reviewing the status, resource usage, and configuration of a node. You can query the following:
- Kubelet’s status on a node.
- Cluster node journal logs.
Crio issues: A cluster administrator can verify CRI-O container runtime engine status on each cluster node. If you experience container runtime issues, perform the following:
- Gather CRI-O journald unit logs.
- Cleaning CRI-O storage.
Operating system issues: OpenShift Container Platform runs on Red Hat Enterprise Linux CoreOS. If you experience operating system issues, you can investigate kernel crash procedures. Ensure the following:
- Enable kdump.
- Test the kdump configuration.
- Analyze a core dump.
Network issues: To troubleshoot Open vSwitch issues, a cluster administrator can perform the following:
- Configure the Open vSwitch log level temporarily.
- Configure the Open vSwitch log level permanently.
- Display Open vSwitch logs.
Operator issues: A cluster administrator can do the following to resolve Operator issues:
- Verify Operator subscription status.
- Check Operator pod health.
- Gather Operator logs.
Pod issues: A cluster administrator can troubleshoot pod-related issues by reviewing the status of a pod and completing the following:
- Review pod and container logs.
- Start debug pods with root access.
Source-to-image issues: A cluster administrator can observe the S2I stages to determine where in the S2I process a failure occurred. Gather the following to resolve Source-to-Image (S2I) issues:
- Source-to-Image diagnostic data.
- Application diagnostic data to investigate application failure.
Storage issues: A multi-attach storage error occurs when the mounting volume on a new node is not possible because the failed node cannot unmount the attached volume. A cluster administrator can do the following to resolve multi-attach storage issues:
- Enable multiple attachments by using RWX volumes.
- Recover or delete the failed node when using an RWO volume.
Monitoring issues: A cluster administrator can follow the procedures on the troubleshooting page for monitoring. If the metrics for your user-defined projects are unavailable or if Prometheus is consuming a lot of disk space, check the following:
- Investigate why user-defined metrics are unavailable.
- Determine why Prometheus is consuming a lot of disk space.
Logging issues: A cluster administrator can follow the procedures on the troubleshooting page for OpenShift Logging issues. Check the following to resolve logging issues:
- OpenShift CLI (oc) issues: Investigate OpenShift CLI (oc) issues by increasing the log level.
Chapter 2. Managing your cluster resources
You can apply global configuration options in OpenShift Container Platform. Operators apply these configuration settings across the cluster.
2.1. Interacting with your cluster resources
You can interact with cluster resources by using the OpenShift CLI (oc
) tool in OpenShift Container Platform. The cluster resources that you see after running the oc api-resources
command can be edited.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have access to the web console or you have installed the
oc
CLI tool.
Procedure
To see which configuration Operators have been applied, run the following command:
$ oc api-resources -o name | grep config.openshift.io
To see what cluster resources you can configure, run the following command:
$ oc explain <resource_name>.config.openshift.io
To see the configuration of custom resource definition (CRD) objects in the cluster, run the following command:
$ oc get <resource_name>.config -o yaml
To edit the cluster resource configuration, run the following command:
$ oc edit <resource_name>.config -o yaml
Chapter 3. Getting support
3.1. Getting support
If you experience difficulty with a procedure described in this documentation, or with OpenShift Container Platform in general, visit the Red Hat Customer Portal. From the Customer Portal, you can:
- Search or browse through the Red Hat Knowledgebase of articles and solutions relating to Red Hat products.
- Submit a support case to Red Hat Support.
- Access other product documentation.
To identify issues with your cluster, you can use Insights in OpenShift Cluster Manager. Insights provides details about issues and, if available, information on how to solve a problem.
If you have a suggestion for improving this documentation or have found an error, submit a Jira issue for the most relevant documentation component. Please provide specific details, such as the section name and OpenShift Container Platform version.
3.2. About the Red Hat Knowledgebase
The Red Hat Knowledgebase provides rich content aimed at helping you make the most of Red Hat’s products and technologies. The Red Hat Knowledgebase consists of articles, product documentation, and videos outlining best practices on installing, configuring, and using Red Hat products. In addition, you can search for solutions to known issues, each providing concise root cause descriptions and remedial steps.
3.3. Searching the Red Hat Knowledgebase
In the event of an OpenShift Container Platform issue, you can perform an initial search to determine if a solution already exists within the Red Hat Knowledgebase.
Prerequisites
- You have a Red Hat Customer Portal account.
Procedure
- Log in to the Red Hat Customer Portal.
In the main Red Hat Customer Portal search field, input keywords and strings relating to the problem, including:
- OpenShift Container Platform components (such as etcd)
- Related procedure (such as installation)
- Warnings, error messages, and other outputs related to explicit failures
- Click Search.
- Select the OpenShift Container Platform product filter.
- Select the Knowledgebase content type filter.
3.4. Submitting a support case
Prerequisites
-
You have installed the OpenShift CLI (
oc
). - You have a Red Hat Customer Portal account.
- You have access to OpenShift Cluster Manager.
Procedure
- Log in to the Red Hat Customer Portal and select SUPPORT CASES → Open a case.
- Select the appropriate category for your issue (such as Defect / Bug), product (OpenShift Container Platform), and product version (4.8, if this is not already autofilled).
- Review the list of suggested Red Hat Knowledgebase solutions for a potential match against the problem that is being reported. If the suggested articles do not address the issue, click Continue.
- Enter a concise but descriptive problem summary and further details about the symptoms being experienced, as well as your expectations.
- Review the updated list of suggested Red Hat Knowledgebase solutions for a potential match against the problem that is being reported. The list is refined as you provide more information during the case creation process. If the suggested articles do not address the issue, click Continue.
- Ensure that the account information presented is as expected, and if not, amend accordingly.
Check that the autofilled OpenShift Container Platform Cluster ID is correct. If it is not, manually obtain your cluster ID.
To manually obtain your cluster ID using the OpenShift Container Platform web console:
- Navigate to Home → Dashboards → Overview.
- Find the value in the Cluster ID field of the Details section.
Alternatively, it is possible to open a new support case through the OpenShift Container Platform web console and have your cluster ID autofilled.
- From the toolbar, navigate to (?) Help → Open Support Case.
- The Cluster ID value is autofilled.
To obtain your cluster ID using the OpenShift CLI (
oc
), run the following command:$ oc get clusterversion -o jsonpath='{.items[].spec.clusterID}{"\n"}'
Complete the following questions where prompted and then click Continue:
- Where are you experiencing the behavior? What environment?
- When does the behavior occur? Frequency? Repeatedly? At certain times?
- What information can you provide around time-frames and the business impact?
-
Upload relevant diagnostic data files and click Continue. It is recommended to include data gathered using the
oc adm must-gather
command as a starting point, plus any issue specific data that is not collected by that command. - Input relevant case management details and click Continue.
- Preview the case details and click Submit.
3.5. Additional resources
- For details about identifying issues with your cluster, see Using Insights to identify issues with your cluster.
Chapter 4. Remote health monitoring with connected clusters
4.1. About remote health monitoring
OpenShift Container Platform collects telemetry and configuration data about your cluster and reports it to Red Hat by using the Telemeter Client and the Insights Operator. The data that is provided to Red Hat enables the benefits outlined in this document.
A cluster that reports data to Red Hat through Telemetry and the Insights Operator is considered a connected cluster.
Telemetry is the term that Red Hat uses to describe the information being sent to Red Hat by the OpenShift Container Platform Telemeter Client. Lightweight attributes are sent from connected clusters to Red Hat to enable subscription management automation, monitor the health of clusters, assist with support, and improve customer experience.
The Insights Operator gathers OpenShift Container Platform configuration data and sends it to Red Hat. The data is used to produce insights about potential issues that a cluster might be exposed to. These insights are communicated to cluster administrators on console.redhat.com/openshift.
More information is provided in this document about these two processes.
Telemetry and Insights Operator benefits
Telemetry and the Insights Operator enable the following benefits for end-users:
- Enhanced identification and resolution of issues. Events that might seem normal to an end-user can be observed by Red Hat from a broader perspective across a fleet of clusters. Some issues can be more rapidly identified from this point of view and resolved without an end-user needing to open a support case or file a Jira issue.
-
Advanced release management. OpenShift Container Platform offers the
candidate
,fast
, andstable
release channels, which enable you to choose an update strategy. The graduation of a release fromfast
tostable
is dependent on the success rate of updates and on the events seen during upgrades. With the information provided by connected clusters, Red Hat can improve the quality of releases tostable
channels and react more rapidly to issues found in thefast
channels. - Targeted prioritization of new features and functionality. The data collected provides insights about which areas of OpenShift Container Platform are used most. With this information, Red Hat can focus on developing the new features and functionality that have the greatest impact for our customers.
- A streamlined support experience. You can provide a cluster ID for a connected cluster when creating a support ticket on the Red Hat Customer Portal. This enables Red Hat to deliver a streamlined support experience that is specific to your cluster, by using the connected information. This document provides more information about that enhanced support experience.
- Predictive analytics. The insights displayed for your cluster on console.redhat.com/openshift are enabled by the information collected from connected clusters. Red Hat is investing in applying deep learning, machine learning, and artificial intelligence automation to help identify issues that OpenShift Container Platform clusters are exposed to.
4.1.1. About Telemetry
Telemetry sends a carefully chosen subset of the cluster monitoring metrics to Red Hat. The Telemeter Client fetches the metrics values every four minutes and thirty seconds and uploads the data to Red Hat. These metrics are described in this document.
This stream of data is used by Red Hat to monitor the clusters in real-time and to react as necessary to problems that impact our customers. It also allows Red Hat to roll out OpenShift Container Platform upgrades to customers to minimize service impact and continuously improve the upgrade experience.
This debugging information is available to Red Hat Support and Engineering teams with the same restrictions as accessing data reported through support cases. All connected cluster information is used by Red Hat to help make OpenShift Container Platform better and more intuitive to use.
Additional resources
- See the OpenShift Container Platform update documentation for more information about updating or upgrading a cluster.
4.1.1.1. Information collected by Telemetry
The following information is collected by Telemetry:
- The unique random identifier that is generated during an installation
- Version information, including the OpenShift Container Platform cluster version and installed update details that are used to determine update version availability
- Update information, including the number of updates available per cluster, the channel and image repository used for an update, update progress information, and the number of errors that occur in an update
- The name of the provider platform that OpenShift Container Platform is deployed on and the data center location
- Sizing information about clusters, machine types, and machines, including the number of CPU cores and the amount of RAM used for each
- The number of etcd members and the number of objects stored in the etcd cluster
- The OpenShift Container Platform framework components installed in a cluster and their condition and status
- Usage information about components, features, and extensions
- Usage details about Technology Previews and unsupported configurations
- Information about degraded software
-
Information about nodes that are marked as
NotReady
- Events for all namespaces listed as "related objects" for a degraded Operator
- Configuration details that help Red Hat Support to provide beneficial support for customers, including node configuration at the cloud infrastructure level, hostnames, IP addresses, Kubernetes pod names, namespaces, and services
- Information about the validity of certificates
- Number of application builds by build strategy type
Telemetry does not collect identifying information such as user names or passwords. Red Hat does not intend to collect personal information. If Red Hat discovers that personal information has been inadvertently received, Red Hat will delete such information. To the extent that any telemetry data constitutes personal data, please refer to the Red Hat Privacy Statement for more information about Red Hat’s privacy practices.
Additional resources
- See Showing data collected by Telemetry for details about how to list the attributes that Telemetry gathers from Prometheus in OpenShift Container Platform.
- See the upstream cluster-monitoring-operator source code for a list of the attributes that Telemetry gathers from Prometheus.
- Telemetry is installed and enabled by default. If you need to opt out of remote health reporting, see Opting out of remote health reporting.
4.1.2. About the Insights Operator
The Insights Operator periodically gathers configuration and component failure status and, by default, reports that data every two hours to Red Hat. This information enables Red Hat to assess configuration and deeper failure data than is reported through Telemetry.
Users of OpenShift Container Platform can display the report of each cluster in the Insights Advisor service on Red Hat Hybrid Cloud Console. If any issues have been identified, Insights provides further details and, if available, steps on how to solve a problem.
The Insights Operator does not collect identifying information, such as user names, passwords, or certificates. See Red Hat Insights Data & Application Security for information about Red Hat Insights data collection and controls.
Red Hat uses all connected cluster information to:
- Identify potential cluster issues and provide a solution and preventive actions in the Insights Advisor service on Red Hat Hybrid Cloud Console
- Improve OpenShift Container Platform by providing aggregated and critical information to product and support teams
- Make OpenShift Container Platform more intuitive
Additional resources
- The Insights Operator is installed and enabled by default. If you need to opt out of remote health reporting, see Opting out of remote health reporting.
4.1.2.1. Information collected by the Insights Operator
The following information is collected by the Insights Operator:
- General information about your cluster and its components to identify issues that are specific to your OpenShift Container Platform version and environment
- Configuration files, such as the image registry configuration, of your cluster to determine incorrect settings and issues that are specific to parameters you set
- Errors that occur in the cluster components
- Progress information of running updates, and the status of any component upgrades
- Details of the platform that OpenShift Container Platform is deployed on, such as Amazon Web Services, and the region that the cluster is located in
- Cluster workload information transformed into discreet Secure Hash Algorithm (SHA) values, which allows Red Hat to assess workloads for security and version vulnerabilities without disclosing sensitive details
-
If an Operator reports an issue, information is collected about core OpenShift Container Platform pods in the
openshift-*
andkube-*
projects. This includes state, resource, security context, volume information, and more.
Additional resources
- See Showing data collected by the Insights Operator for details about how to review the data that is collected by the Insights Operator.
- The Insights Operator source code is available for review and contribution. See the Insights Operator upstream project for a list of the items collected by the Insights Operator.
4.1.3. Understanding Telemetry and Insights Operator data flow
The Telemeter Client collects selected time series data from the Prometheus API. The time series data is uploaded to api.openshift.com every four minutes and thirty seconds for processing.
The Insights Operator gathers selected data from the Kubernetes API and the Prometheus API into an archive. The archive is uploaded to console.redhat.com every two hours for processing. The Insights Operator also downloads the latest Insights analysis from console.redhat.com. This is used to populate the Insights status pop-up that is included in the Overview page in the OpenShift Container Platform web console.
All of the communication with Red Hat occurs over encrypted channels by using Transport Layer Security (TLS) and mutual certificate authentication. All of the data is encrypted in transit and at rest.
Access to the systems that handle customer data is controlled through multi-factor authentication and strict authorization controls. Access is granted on a need-to-know basis and is limited to required operations.
Telemetry and Insights Operator data flow
Additional resources
- See Monitoring overview for more information about the OpenShift Container Platform monitoring stack.
- See Configuring your firewall for details about configuring a firewall and enabling endpoints for Telemetry and Insights
4.1.4. Additional details about how remote health monitoring data is used
The information collected to enable remote health monitoring is detailed in Information collected by Telemetry and Information collected by the Insights Operator.
As further described in the preceding sections of this document, Red Hat collects data about your use of the Red Hat Product(s) for purposes such as providing support and upgrades, optimizing performance or configuration, minimizing service impacts, identifying and remediating threats, troubleshooting, improving the offerings and user experience, responding to issues, and for billing purposes if applicable.
Collection safeguards
Red Hat employs technical and organizational measures designed to protect the telemetry and configuration data.
Sharing
Red Hat may share the data collected through Telemetry and the Insights Operator internally within Red Hat to improve your user experience. Red Hat may share telemetry and configuration data with its business partners in an aggregated form that does not identify customers to help the partners better understand their markets and their customers’ use of Red Hat offerings or to ensure the successful integration of products jointly supported by those partners.
Third parties
Red Hat may engage certain third parties to assist in the collection, analysis, and storage of the Telemetry and configuration data.
User control / enabling and disabling telemetry and configuration data collection
You may disable OpenShift Container Platform Telemetry and the Insights Operator by following the instructions in Opting out of remote health reporting.
4.2. Showing data collected by remote health monitoring
As an administrator, you can review the metrics collected by Telemetry and the Insights Operator.
4.2.1. Showing data collected by Telemetry
You can see the cluster and components time series data captured by Telemetry.
Prerequisites
-
Install the OpenShift CLI (
oc
). -
You must log in to the cluster with a user that has either the
cluster-admin
role or thecluster-monitoring-view
role.
Procedure
Find the URL for the Prometheus service that runs in the OpenShift Container Platform cluster:
$ oc get route prometheus-k8s -n openshift-monitoring -o jsonpath="{.spec.host}"
- Navigate to the URL.
Enter this query in the Expression input box and press Execute:
{__name__=~"cluster:usage:.*|count:up0|count:up1|cluster_version|cluster_version_available_updates|cluster_operator_up|cluster_operator_conditions|cluster_version_payload|cluster_installer|cluster_infrastructure_provider|cluster_feature_set|instance:etcd_object_counts:sum|ALERTS|code:apiserver_request_total:rate:sum|cluster:capacity_cpu_cores:sum|cluster:capacity_memory_bytes:sum|cluster:cpu_usage_cores:sum|cluster:memory_usage_bytes:sum|openshift:cpu_usage_cores:sum|openshift:memory_usage_bytes:sum|workload:cpu_usage_cores:sum|workload:memory_usage_bytes:sum|cluster:virt_platform_nodes:sum|cluster:node_instance_type_count:sum|cnv:vmi_status_running:count|node_role_os_version_machine:cpu_capacity_cores:sum|node_role_os_version_machine:cpu_capacity_sockets:sum|subscription_sync_total|csv_succeeded|csv_abnormal|ceph_cluster_total_bytes|ceph_cluster_total_used_raw_bytes|ceph_health_status|job:ceph_osd_metadata:count|job:kube_pv:count|job:ceph_pools_iops:total|job:ceph_pools_iops_bytes:total|job:ceph_versions_running:count|job:noobaa_total_unhealthy_buckets:sum|job:noobaa_bucket_count:sum|job:noobaa_total_object_count:sum|noobaa_accounts_num|noobaa_total_usage|console_url|cluster:network_attachment_definition_instances:max|cluster:network_attachment_definition_enabled_instance_up:max|insightsclient_request_send_total|cam_app_workload_migrations|cluster:apiserver_current_inflight_requests:sum:max_over_time:2m|cluster:telemetry_selected_series:count",alertstate=~"firing|"}
This query replicates the request that Telemetry makes against a running OpenShift Container Platform cluster’s Prometheus service and returns the full set of time series captured by Telemetry.
4.2.2. Showing data collected by the Insights Operator
You can review the data that is collected by the Insights Operator.
Prerequisites
-
Access to the cluster as a user with the
cluster-admin
role.
Procedure
Find the name of the currently running pod for the Insights Operator:
$ INSIGHTS_OPERATOR_POD=$(oc get pods --namespace=openshift-insights -o custom-columns=:metadata.name --no-headers --field-selector=status.phase=Running)
Copy the recent data archives collected by the Insights Operator:
$ oc cp openshift-insights/$INSIGHTS_OPERATOR_POD:/var/lib/insights-operator ./insights-data
The recent Insights Operator archives are now available in the insights-data
directory.
4.3. Opting out of remote health reporting
You may choose to opt out of reporting health and usage data for your cluster.
To opt out of remote health reporting, you must:
- Modify the global cluster pull secret to disable remote health reporting.
- Update the cluster to use this modified pull secret.
4.3.1. Consequences of disabling remote health reporting
In OpenShift Container Platform, customers can opt out of reporting usage information. However, connected clusters allow Red Hat to react more quickly to problems and better support our customers, as well as better understand how product upgrades impact clusters. Connected clusters also help to simplify the subscription and entitlement process and enable the Red Hat OpenShift Cluster Manager service to provide an overview of your clusters and their subscription status.
Red Hat strongly recommends leaving health and usage reporting enabled for pre-production and test clusters even if it is necessary to opt out for production clusters. This allows Red Hat to be a participant in qualifying OpenShift Container Platform in your environments and react more rapidly to product issues.
Some of the consequences of opting out of having a connected cluster are:
- Red Hat will not be able to monitor the success of product upgrades or the health of your clusters without a support case being opened.
- Red Hat will not be able to use configuration data to better triage customer support cases and identify which configurations our customers find important.
- The Red Hat OpenShift Cluster Manager will not show data about your clusters including health and usage information.
- Your subscription entitlement information must be manually entered via console.redhat.com without the benefit of automatic usage reporting.
In restricted networks, Telemetry and Insights data can still be reported through appropriate configuration of your proxy.
4.3.2. Modifying the global cluster pull secret to disable remote health reporting
You can modify your existing global cluster pull secret to disable remote health reporting. This disables both Telemetry and the Insights Operator.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role.
Procedure
Download the global cluster pull secret to your local file system.
$ oc extract secret/pull-secret -n openshift-config --to=.
-
In a text editor, edit the
.dockerconfigjson
file that was downloaded. Remove the
cloud.openshift.com
JSON entry, for example:"cloud.openshift.com":{"auth":"<hash>","email":"<email_address>"}
- Save the file.
You can now update your cluster to use this modified pull secret.
4.3.3. Updating the global cluster pull secret
You can update the global pull secret for your cluster by either replacing the current pull secret or appending a new pull secret.
The procedure is required when users use a separate registry to store images than the registry used during installation.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role.
Procedure
Optional: To append a new pull secret to the existing pull secret, complete the following steps:
Enter the following command to download the pull secret:
$ oc get secret/pull-secret -n openshift-config --template='{{index .data ".dockerconfigjson" | base64decode}}' ><pull_secret_location> 1
- 1
- Provide the path to the pull secret file.
Enter the following command to add the new pull secret:
$ oc registry login --registry="<registry>" \ 1 --auth-basic="<username>:<password>" \ 2 --to=<pull_secret_location> 3
Alternatively, you can perform a manual update to the pull secret file.
Enter the following command to update the global pull secret for your cluster:
$ oc set data secret/pull-secret -n openshift-config --from-file=.dockerconfigjson=<pull_secret_location> 1
- 1
- Provide the path to the new pull secret file.
This update is rolled out to all nodes, which can take some time depending on the size of your cluster.
NoteAs of OpenShift Container Platform 4.7.4, changes to the global pull secret no longer trigger a node drain or reboot.
4.4. Using Insights to identify issues with your cluster
Insights repeatedly analyzes the data Insights Operator sends. Users of OpenShift Container Platform can display the report in the Insights Advisor service on Red Hat Hybrid Cloud Console.
4.4.1. About Red Hat Insights Advisor for OpenShift Container Platform
You can use Insights Advisor to assess and monitor the health of your OpenShift Container Platform clusters. Whether you are concerned about individual clusters, or with your whole infrastructure, it is important to be aware of your exposure to issues that can affect service availability, fault tolerance, performance, or security.
Insights repeatedly analyzes the data that Insights Operator sends using a database of recommendations, which are sets of conditions that can leave your OpenShift Container Platform clusters at risk. Your data is then uploaded to the Insights Advisor service on Red Hat Hybrid Cloud Console where you can perform the following actions:
- See clusters impacted by a specific recommendation.
- Use robust filtering capabilities to refine your results to those recommendations.
- Learn more about individual recommendations, details about the risks they present, and get resolutions tailored to your individual clusters.
- Share results with other stakeholders.
4.4.2. Understanding Insights Advisor recommendations
Insights Advisor bundles information about various cluster states and component configurations that can negatively affect the service availability, fault tolerance, performance, or security of your clusters. This information set is called a recommendation in Insights Advisor and includes the following information:
- Name: A concise description of the recommendation
- Added: When the recommendation was published to the Insights Advisor archive
- Category: Whether the issue has the potential to negatively affect service availability, fault tolerance, performance, or security
- Total risk: A value derived from the likelihood that the condition will negatively affect your infrastructure, and the impact on operations if that were to happen
- Clusters: A list of clusters on which a recommendation is detected
- Description: A brief synopsis of the issue, including how it affects your clusters
- Link to associated topics: More information from Red Hat about the issue
4.4.3. Displaying potential issues with your cluster
This section describes how to display the Insights report in Insights Advisor on Red Hat Hybrid Cloud Console.
Note that Insights repeatedly analyzes your cluster and shows the latest results. These results can change, for example, if you fix an issue or a new issue has been detected.
Prerequisites
- Your cluster is registered on Red Hat Hybrid Cloud Console.
- Remote health reporting is enabled, which is the default.
- You are logged in to Red Hat Hybrid Cloud Console.
Procedure
Navigate to Advisor → Recommendations on Red Hat Hybrid Cloud Console.
Depending on the result, Insights Advisor displays one of the following:
- No matching recommendations found, if Insights did not identify any issues.
- A list of issues Insights has detected, grouped by risk (low, moderate, important, and critical).
- No clusters yet, if Insights has not yet analyzed the cluster. The analysis starts shortly after the cluster has been installed, registered, and connected to the internet.
If any issues are displayed, click the > icon in front of the entry for more details.
Depending on the issue, the details can also contain a link to more information from Red Hat about the issue.
4.4.4. Displaying all Insights Advisor recommendations
The Recommendations view, by default, only displays the recommendations that are detected on your clusters. However, you can view all of the recommendations in the advisor archive.
Prerequisites
- Remote health reporting is enabled, which is the default.
- Your cluster is registered on Red Hat Hybrid Cloud Console.
- You are logged in to Red Hat Hybrid Cloud Console.
Procedure
- Navigate to Advisor → Recommendations on Red Hat Hybrid Cloud Console.
Click the X icons next to the Clusters Impacted and Status filters.
You can now browse through all of the potential recommendations for your cluster.
4.4.5. Disabling Insights Advisor recommendations
You can disable specific recommendations that affect your clusters, so that they no longer appear in your reports. It is possible to disable a recommendation for a single cluster or all of your clusters.
Disabling a recommendation for all of your clusters also applies to any future clusters.
Prerequisites
- Remote health reporting is enabled, which is the default.
- Your cluster is registered on Red Hat Hybrid Cloud Console.
- You are logged in to Red Hat Hybrid Cloud Console.
Procedure
- Navigate to Advisor → Recommendations on Red Hat Hybrid Cloud Console.
- Click the name of the recommendation to disable. You are directed to the single recommendation page.
To disable the recommendation for a single cluster:
- Click the Options menu for that cluster, and then click Disable recommendation for cluster.
- Enter a justification note and click Save.
To disable the recommendation for all of your clusters:
- Click Actions → Disable recommendation.
- Enter a justification note and click Save.
4.4.6. Enabling a previously disabled Insights Advisor recommendation
When a recommendation is disabled for all clusters, you will no longer see the recommendation in Insights Advisor. You can change this behavior.
Prerequisites
- Remote health reporting is enabled, which is the default.
- Your cluster is registered on Red Hat Hybrid Cloud Console.
- You are logged in to Red Hat Hybrid Cloud Console.
Procedure
- Navigate to Advisor → Recommendations on Red Hat Hybrid Cloud Console.
- Filter the recommendations by Status → Disabled.
- Locate the recommendation to enable.
- Click the Options menu , and then click Enable recommendation.
4.4.7. Displaying the Insights status in the web console
Insights repeatedly analyzes your cluster and you can display the status of identified potential issues of your cluster in the OpenShift Container Platform web console. This status shows the number of issues in the different categories and, for further details, links to the reports in OpenShift Cluster Manager.
Prerequisites
- Your cluster is registered in OpenShift Cluster Manager.
- Remote health reporting is enabled, which is the default.
- You are logged in to the OpenShift Container Platform web console.
Procedure
- Navigate to Home → Overview in the OpenShift Container Platform web console.
Click Insights on the Status card.
The pop-up window lists potential issues grouped by risk. Click the individual categories or View all recommendations in Insights Advisor to display more details.
4.5. Using Insights Operator
The Insights Operator periodically gathers configuration and component failure status and, by default, reports that data every two hours to Red Hat. This information enables Red Hat to assess configuration and deeper failure data than is reported through Telemetry. Users of OpenShift Container Platform can display the report in the Insights Advisor service on Red Hat Hybrid Cloud Console.
Additional resources
- The Insights Operator is installed and enabled by default. If you need to opt out of remote health reporting, see Opting out of remote health reporting.
- For more information on using Insights Advisor to identify issues with your cluster, see Using Insights to identify issues with your cluster.
4.5.1. Downloading your Insights Operator archive
Insights Operator stores gathered data in an archive located in the openshift-insights
namespace of your cluster. You can download and review the data that is gathered by the Insights Operator.
Prerequisites
-
Access to the cluster as a user with the
cluster-admin
role.
Procedure
Find the name of the running pod for the Insights Operator:
$ oc get pods --namespace=openshift-insights -o custom-columns=:metadata.name --no-headers --field-selector=status.phase=Running
Copy the recent data archives collected by the Insights Operator:
$ oc cp openshift-insights/<insights_operator_pod_name>:/var/lib/insights-operator ./insights-data 1
- 1
- Replace
<insights_operator_pod_name>
with the pod name output from the preceding command.
The recent Insights Operator archives are now available in the insights-data
directory.
4.5.2. Viewing Insights Operator gather durations
You can view the time it takes for the Insights Operator to gather the information contained in the archive. This helps you to understand Insights Operator resource usage and issues with Insights Advisor.
Prerequisites
- A recent copy of your Insights Operator archive.
Procedure
From your archive, open
/insights-operator/gathers.json
.The file contains a list of Insights Operator gather operations:
{ "name": "clusterconfig/authentication", "duration_in_ms": 730, 1 "records_count": 1, "errors": null, "panic": null }
- 1
duration_in_ms
is the amount of time in milliseconds for each gather operation.
- Inspect each gather operation for abnormalities.
4.6. Using remote health reporting in a restricted network
You can manually gather and upload Insights Operator archives to diagnose issues from a restricted network.
To use the Insights Operator in a restricted network, you must:
- Create a copy of your Insights Operator archive.
- Upload the Insights Operator archive to console.redhat.com.
Additionally, you can choose to obfuscate the Insights Operator data before upload.
4.6.1. Running an Insights Operator gather operation
You must run a gather operation to create an Insights Operator archive.
Prerequisites
-
You are logged in to OpenShift Container Platform as
cluster-admin
.
Procedure
Create a file named
gather-job.yaml
using this template:apiVersion: batch/v1 kind: Job metadata: name: insights-operator-job annotations: config.openshift.io/inject-proxy: insights-operator spec: backoffLimit: 6 ttlSecondsAfterFinished: 600 template: spec: restartPolicy: OnFailure serviceAccountName: operator nodeSelector: beta.kubernetes.io/os: linux node-role.kubernetes.io/master: "" tolerations: - effect: NoSchedule key: node-role.kubernetes.io/master operator: Exists - effect: NoExecute key: node.kubernetes.io/unreachable operator: Exists tolerationSeconds: 900 - effect: NoExecute key: node.kubernetes.io/not-ready operator: Exists tolerationSeconds: 900 volumes: - name: snapshots emptyDir: {} - name: service-ca-bundle configMap: name: service-ca-bundle optional: true initContainers: - name: insights-operator image: quay.io/openshift/origin-insights-operator:latest terminationMessagePolicy: FallbackToLogsOnError volumeMounts: - name: snapshots mountPath: /var/lib/insights-operator - name: service-ca-bundle mountPath: /var/run/configmaps/service-ca-bundle readOnly: true ports: - containerPort: 8443 name: https resources: requests: cpu: 10m memory: 70Mi args: - gather - -v=4 - --config=/etc/insights-operator/server.yaml containers: - name: sleepy image: quay.io/openshift/origin-base:latest args: - /bin/sh - -c - sleep 10m volumeMounts: [{name: snapshots, mountPath: /var/lib/insights-operator}]
Copy your
insights-operator
image version:$ oc get -n openshift-insights deployment insights-operator -o yaml
Paste your image version in
gather-job.yaml
:initContainers: - name: insights-operator image: <your_insights_operator_image_version> terminationMessagePolicy: FallbackToLogsOnError volumeMounts:
Create the gather job:
$ oc apply -n openshift-insights -f gather-job.yaml
Find the name of the job pod:
$ oc describe -n openshift-insights job/insights-operator-job
Example output
Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulCreate 7m18s job-controller Created pod: insights-operator-job-<your_job>
where
insights-operator-job-<your_job>
is the name of the pod.Verify that the operation has finished:
$ oc logs -n openshift-insights insights-operator-job-<your_job> insights-operator
Example output
I0407 11:55:38.192084 1 diskrecorder.go:34] Wrote 108 records to disk in 33ms
Save the created archive:
$ oc cp openshift-insights/insights-operator-job-<your_job>:/var/lib/insights-operator ./insights-data
Clean up the job:
$ oc delete -n openshift-insights job insights-operator-job
4.6.2. Uploading an Insights Operator archive
You can manually upload an Insights Operator archive to console.redhat.com to diagnose potential issues.
Prerequisites
-
You are logged in to OpenShift Container Platform as
cluster-admin
. - You have a workstation with unrestricted internet access.
- You have created a copy of the Insights Operator archive.
Procedure
Download the
dockerconfig.json
file:$ oc extract secret/pull-secret -n openshift-config --to=.
Copy your
"cloud.openshift.com"
"auth"
token from thedockerconfig.json
file:{ "auths": { "cloud.openshift.com": { "auth": "<your_token>", "email": "asd@redhat.com" } }
Upload the archive to console.redhat.com:
$ curl -v -H "User-Agent: insights-operator/one10time200gather184a34f6a168926d93c330 cluster/<cluster_id>" -H "Authorization: Bearer <your_token>" -F "upload=@<path_to_archive>; type=application/vnd.redhat.openshift.periodic+tar" https://console.redhat.com/api/ingress/v1/upload
where
<cluster_id>
is your cluster ID,<your_token>
is the token from your pull secret, and<path_to_archive>
is the path to the Insights Operator archive.If the operation is successful, the command returns a
"request_id"
and"account_number"
:Example output
* Connection #0 to host console.redhat.com left intact {"request_id":"393a7cf1093e434ea8dd4ab3eb28884c","upload":{"account_number":"6274079"}}%
Verification steps
- Log in to https://console.redhat.com/openshift.
- Click the Clusters menu in the left pane.
- To display the details of the cluster, click the cluster name.
Open the Insights Advisor tab of the cluster.
If the upload was successful, the tab displays one of the following:
- Your cluster passed all recommendations, if Insights Advisor did not identify any issues.
- A list of issues that Insights Advisor has detected, prioritized by risk (low, moderate, important, and critical).
4.6.3. Enabling Insights Operator data obfuscation
You can enable obfuscation to mask sensitive and identifiable IPv4 addresses and cluster base domains that the Insights Operator sends to console.redhat.com.
Although this feature is available, Red Hat recommends keeping obfuscation disabled for a more effective support experience.
Obfuscation assigns non-identifying values to cluster IPv4 addresses, and uses a translation table that is retained in memory to change IP addresses to their obfuscated versions throughout the Insights Operator archive before uploading the data to console.redhat.com.
For cluster base domains, obfuscation changes the base domain to a hardcoded substring. For example, cluster-api.openshift.example.com
becomes cluster-api.<CLUSTER_BASE_DOMAIN>
.
The following procedure enables obfuscation using the support
secret in the openshift-config
namespace.
Prerequisites
-
You are logged in to the OpenShift Container Platform web console as
cluster-admin
.
Procedure
- Navigate to Workloads → Secrets.
- Select the openshift-config project.
- Search for the support secret using the Search by name field. If it does not exist, click Create → Key/value secret to create it.
- Click the Options menu , and then click Edit Secret.
- Click Add Key/Value.
-
Create a key named
enableGlobalObfuscation
with a value oftrue
, and click Save. - Navigate to Workloads → Pods
-
Select the
openshift-insights
project. -
Find the
insights-operator
pod. -
To restart the
insights-operator
pod, click the Options menu , and then click Delete Pod.
Verification
- Navigate to Workloads → Secrets.
- Select the openshift-insights project.
- Search for the obfuscation-translation-table secret using the Search by name field.
If the obfuscation-translation-table
secret exists, then obfuscation is enabled and working.
Alternatively, you can inspect /insights-operator/gathers.json
in your Insights Operator archive for the value "is_global_obfuscation_enabled": true
.
Additional resources
- For more information on how to download your Insights Operator archive, see Showing data collected by the Insights Operator.
Chapter 5. Gathering data about your cluster
When opening a support case, it is helpful to provide debugging information about your cluster to Red Hat Support.
It is recommended to provide:
5.1. About the must-gather tool
The oc adm must-gather
CLI command collects the information from your cluster that is most likely needed for debugging issues, including:
- Resource definitions
- Service logs
By default, the oc adm must-gather
command uses the default plugin image and writes into ./must-gather.local
.
Alternatively, you can collect specific information by running the command with the appropriate arguments as described in the following sections:
To collect data related to one or more specific features, use the
--image
argument with an image, as listed in a following section.For example:
$ oc adm must-gather --image=registry.redhat.io/container-native-virtualization/cnv-must-gather-rhel8:v4.9.0
To collect the audit logs, use the
-- /usr/bin/gather_audit_logs
argument, as described in a following section.For example:
$ oc adm must-gather -- /usr/bin/gather_audit_logs
NoteAudit logs are not collected as part of the default set of information to reduce the size of the files.
When you run oc adm must-gather
, a new pod with a random name is created in a new project on the cluster. The data is collected on that pod and saved in a new directory that starts with must-gather.local
. This directory is created in the current working directory.
For example:
NAMESPACE NAME READY STATUS RESTARTS AGE ... openshift-must-gather-5drcj must-gather-bklx4 2/2 Running 0 72s openshift-must-gather-5drcj must-gather-s8sdh 2/2 Running 0 72s ...
5.1.1. Gathering data about your cluster for Red Hat Support
You can gather debugging information about your cluster by using the oc adm must-gather
CLI command.
Prerequisites
-
Access to the cluster as a user with the
cluster-admin
role. -
The OpenShift Container Platform CLI (
oc
) installed.
Procedure
Navigate to the directory where you want to store the
must-gather
data.NoteIf your cluster is using a restricted network, you must take additional steps. If your mirror registry has a trusted CA, you must first add the trusted CA to the cluster. For all clusters on restricted networks, you must import the default
must-gather
image as an image stream.$ oc import-image is/must-gather -n openshift
Run the
oc adm must-gather
command:$ oc adm must-gather
NoteBecause this command picks a random control plane node by default, the pod might be scheduled to a control plane node that is in the
NotReady
andSchedulingDisabled
state.If this command fails, for example, if you cannot schedule a pod on your cluster, then use the
oc adm inspect
command to gather information for particular resources.NoteContact Red Hat Support for the recommended resources to gather.
Create a compressed file from the
must-gather
directory that was just created in your working directory. For example, on a computer that uses a Linux operating system, run the following command:$ tar cvaf must-gather.tar.gz must-gather.local.5421342344627712289/ 1
- 1
- Make sure to replace
must-gather-local.5421342344627712289/
with the actual directory name.
- Attach the compressed file to your support case on the Red Hat Customer Portal.
5.1.2. Gathering data about specific features
You can gather debugging information about specific features by using the oc adm must-gather
CLI command with the --image
or --image-stream
argument. The must-gather
tool supports multiple images, so you can gather data about more than one feature by running a single command.
Image | Purpose |
---|---|
| Data collection for OpenShift Virtualization. |
| Data collection for OpenShift Serverless. |
| Data collection for Red Hat OpenShift Service Mesh. |
| Data collection for the Migration Toolkit for Containers. |
| Data collection for Red Hat OpenShift Container Storage. |
| Data collection for OpenShift Logging. |
| Data collection for Local Storage Operator. |
To collect the default must-gather
data in addition to specific feature data, add the --image-stream=openshift/must-gather
argument.
Prerequisites
-
Access to the cluster as a user with the
cluster-admin
role. -
The OpenShift Container Platform CLI (
oc
) installed.
Procedure
-
Navigate to the directory where you want to store the
must-gather
data. Run the
oc adm must-gather
command with one or more--image
or--image-stream
arguments. For example, the following command gathers both the default cluster data and information specific to OpenShift Virtualization:$ oc adm must-gather \ --image-stream=openshift/must-gather \ 1 --image=registry.redhat.io/container-native-virtualization/cnv-must-gather-rhel8:v4.8.7 2
You can use the
must-gather
tool with additional arguments to gather data that is specifically related to OpenShift Logging and the Red Hat OpenShift Logging Operator in your cluster. For OpenShift Logging, run the following command:$ oc adm must-gather --image=$(oc -n openshift-logging get deployment.apps/cluster-logging-operator \ -o jsonpath='{.spec.template.spec.containers[?(@.name == "cluster-logging-operator")].image}')
Example 5.1. Example
must-gather
output for OpenShift Logging├── cluster-logging │ ├── clo │ │ ├── cluster-logging-operator-74dd5994f-6ttgt │ │ ├── clusterlogforwarder_cr │ │ ├── cr │ │ ├── csv │ │ ├── deployment │ │ └── logforwarding_cr │ ├── collector │ │ ├── fluentd-2tr64 │ ├── eo │ │ ├── csv │ │ ├── deployment │ │ └── elasticsearch-operator-7dc7d97b9d-jb4r4 │ ├── es │ │ ├── cluster-elasticsearch │ │ │ ├── aliases │ │ │ ├── health │ │ │ ├── indices │ │ │ ├── latest_documents.json │ │ │ ├── nodes │ │ │ ├── nodes_stats.json │ │ │ └── thread_pool │ │ ├── cr │ │ ├── elasticsearch-cdm-lp8l38m0-1-794d6dd989-4jxms │ │ └── logs │ │ ├── elasticsearch-cdm-lp8l38m0-1-794d6dd989-4jxms │ ├── install │ │ ├── co_logs │ │ ├── install_plan │ │ ├── olmo_logs │ │ └── subscription │ └── kibana │ ├── cr │ ├── kibana-9d69668d4-2rkvz ├── cluster-scoped-resources │ └── core │ ├── nodes │ │ ├── ip-10-0-146-180.eu-west-1.compute.internal.yaml │ └── persistentvolumes │ ├── pvc-0a8d65d9-54aa-4c44-9ecc-33d9381e41c1.yaml ├── event-filter.html ├── gather-debug.log └── namespaces ├── openshift-logging │ ├── apps │ │ ├── daemonsets.yaml │ │ ├── deployments.yaml │ │ ├── replicasets.yaml │ │ └── statefulsets.yaml │ ├── batch │ │ ├── cronjobs.yaml │ │ └── jobs.yaml │ ├── core │ │ ├── configmaps.yaml │ │ ├── endpoints.yaml │ │ ├── events │ │ │ ├── elasticsearch-im-app-1596020400-gm6nl.1626341a296c16a1.yaml │ │ │ ├── elasticsearch-im-audit-1596020400-9l9n4.1626341a2af81bbd.yaml │ │ │ ├── elasticsearch-im-infra-1596020400-v98tk.1626341a2d821069.yaml │ │ │ ├── elasticsearch-im-app-1596020400-cc5vc.1626341a3019b238.yaml │ │ │ ├── elasticsearch-im-audit-1596020400-s8d5s.1626341a31f7b315.yaml │ │ │ ├── elasticsearch-im-infra-1596020400-7mgv8.1626341a35ea59ed.yaml │ │ ├── events.yaml │ │ ├── persistentvolumeclaims.yaml │ │ ├── pods.yaml │ │ ├── replicationcontrollers.yaml │ │ ├── secrets.yaml │ │ └── services.yaml │ ├── openshift-logging.yaml │ ├── pods │ │ ├── cluster-logging-operator-74dd5994f-6ttgt │ │ │ ├── cluster-logging-operator │ │ │ │ └── cluster-logging-operator │ │ │ │ └── logs │ │ │ │ ├── current.log │ │ │ │ ├── previous.insecure.log │ │ │ │ └── previous.log │ │ │ └── cluster-logging-operator-74dd5994f-6ttgt.yaml │ │ ├── cluster-logging-operator-registry-6df49d7d4-mxxff │ │ │ ├── cluster-logging-operator-registry │ │ │ │ └── cluster-logging-operator-registry │ │ │ │ └── logs │ │ │ │ ├── current.log │ │ │ │ ├── previous.insecure.log │ │ │ │ └── previous.log │ │ │ ├── cluster-logging-operator-registry-6df49d7d4-mxxff.yaml │ │ │ └── mutate-csv-and-generate-sqlite-db │ │ │ └── mutate-csv-and-generate-sqlite-db │ │ │ └── logs │ │ │ ├── current.log │ │ │ ├── previous.insecure.log │ │ │ └── previous.log │ │ ├── elasticsearch-cdm-lp8l38m0-1-794d6dd989-4jxms │ │ ├── elasticsearch-im-app-1596030300-bpgcx │ │ │ ├── elasticsearch-im-app-1596030300-bpgcx.yaml │ │ │ └── indexmanagement │ │ │ └── indexmanagement │ │ │ └── logs │ │ │ ├── current.log │ │ │ ├── previous.insecure.log │ │ │ └── previous.log │ │ ├── fluentd-2tr64 │ │ │ ├── fluentd │ │ │ │ └── fluentd │ │ │ │ └── logs │ │ │ │ ├── current.log │ │ │ │ ├── previous.insecure.log │ │ │ │ └── previous.log │ │ │ ├── fluentd-2tr64.yaml │ │ │ └── fluentd-init │ │ │ └── fluentd-init │ │ │ └── logs │ │ │ ├── current.log │ │ │ ├── previous.insecure.log │ │ │ └── previous.log │ │ ├── kibana-9d69668d4-2rkvz │ │ │ ├── kibana │ │ │ │ └── kibana │ │ │ │ └── logs │ │ │ │ ├── current.log │ │ │ │ ├── previous.insecure.log │ │ │ │ └── previous.log │ │ │ ├── kibana-9d69668d4-2rkvz.yaml │ │ │ └── kibana-proxy │ │ │ └── kibana-proxy │ │ │ └── logs │ │ │ ├── current.log │ │ │ ├── previous.insecure.log │ │ │ └── previous.log │ └── route.openshift.io │ └── routes.yaml └── openshift-operators-redhat ├── ...
Run the
oc adm must-gather
command with one or more--image
or--image-stream
arguments. For example, the following command gathers both the default cluster data and information specific to KubeVirt:$ oc adm must-gather \ --image-stream=openshift/must-gather \ 1 --image=quay.io/kubevirt/must-gather 2
Create a compressed file from the
must-gather
directory that was just created in your working directory. For example, on a computer that uses a Linux operating system, run the following command:$ tar cvaf must-gather.tar.gz must-gather.local.5421342344627712289/ 1
- 1
- Make sure to replace
must-gather-local.5421342344627712289/
with the actual directory name.
- Attach the compressed file to your support case on the Red Hat Customer Portal.
5.1.3. Gathering audit logs
You can gather audit logs, which are a security-relevant chronological set of records documenting the sequence of activities that have affected the system by individual users, administrators, or other components of the system. You can gather audit logs for:
- etcd server
- Kubernetes API server
- OpenShift OAuth API server
- OpenShift API server
Procedure
Run the
oc adm must-gather
command with the-- /usr/bin/gather_audit_logs
flag:$ oc adm must-gather -- /usr/bin/gather_audit_logs
Create a compressed file from the
must-gather
directory that was just created in your working directory. For example, on a computer that uses a Linux operating system, run the following command:$ tar cvaf must-gather.tar.gz must-gather.local.472290403699006248 1
- 1
- Replace
must-gather-local.472290403699006248
with the actual directory name.
- Attach the compressed file to your support case on the Red Hat Customer Portal.
5.2. Obtaining your cluster ID
When providing information to Red Hat Support, it is helpful to provide the unique identifier for your cluster. You can have your cluster ID autofilled by using the OpenShift Container Platform web console. You can also manually obtain your cluster ID by using the web console or the OpenShift CLI (oc
).
Prerequisites
-
Access to the cluster as a user with the
cluster-admin
role. -
Access to the web console or the OpenShift CLI (
oc
) installed.
Procedure
To open a support case and have your cluster ID autofilled using the web console:
- From the toolbar, navigate to (?) Help → Open Support Case.
- The Cluster ID value is autofilled.
To manually obtain your cluster ID using the web console:
- Navigate to Home → Dashboards → Overview.
- The value is available in the Cluster ID field of the Details section.
To obtain your cluster ID using the OpenShift CLI (
oc
), run the following command:$ oc get clusterversion -o jsonpath='{.items[].spec.clusterID}{"\n"}'
5.3. About sosreport
sosreport
is a tool that collects configuration details, system information, and diagnostic data from Red Hat Enterprise Linux (RHEL) and Red Hat Enterprise Linux CoreOS (RHCOS) systems. sosreport
provides a standardized way to collect diagnostic information relating to a node, which can then be provided to Red Hat Support for issue diagnosis.
In some support interactions, Red Hat Support may ask you to collect a sosreport
archive for a specific OpenShift Container Platform node. For example, it might sometimes be necessary to review system logs or other node-specific data that is not included within the output of oc adm must-gather
.
5.4. Generating a sosreport archive for an OpenShift Container Platform cluster node
The recommended way to generate a sosreport
for an OpenShift Container Platform 4.8 cluster node is through a debug pod.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - You have SSH access to your hosts.
-
You have installed the OpenShift CLI (
oc
). - You have a Red Hat standard or premium Subscription.
- You have a Red Hat Customer Portal account.
- You have an existing Red Hat Support case ID.
Procedure
Obtain a list of cluster nodes:
$ oc get nodes
Enter into a debug session on the target node. This step instantiates a debug pod called
<node_name>-debug
:$ oc debug node/my-cluster-node
To enter into a debug session on the target node that is tainted with the
NoExecute
effect, add a toleration to a dummy namespace, and start the debug pod in the dummy namespace:$ oc new-project dummy
$ oc patch namespace dummy --type=merge -p '{"metadata": {"annotations": { "scheduler.alpha.kubernetes.io/defaultTolerations": "[{\"operator\": \"Exists\"}]"}}}'
$ oc debug node/my-cluster-node
Set
/host
as the root directory within the debug shell. The debug pod mounts the host’s root file system in/host
within the pod. By changing the root directory to/host
, you can run binaries contained in the host’s executable paths:# chroot /host
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,
oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
instead.Start a
toolbox
container, which includes the required binaries and plugins to runsosreport
:# toolbox
NoteIf an existing
toolbox
pod is already running, thetoolbox
command outputs'toolbox-' already exists. Trying to start…
. Remove the running toolbox container withpodman rm toolbox-
and spawn a new toolbox container, to avoid issues withsosreport
plugins.Collect a
sosreport
archive.Run the
sosreport
command and enable thecrio.all
andcrio.logs
CRI-O container enginesosreport
plugins:# sosreport -k crio.all=on -k crio.logs=on 1
- 1
-k
enables you to definesosreport
plugin parameters outside of the defaults.
- Press Enter when prompted, to continue.
-
Provide the Red Hat Support case ID.
sosreport
adds the ID to the archive’s file name. The
sosreport
output provides the archive’s location and checksum. The following sample output references support case ID01234567
:Your sosreport has been generated and saved in: /host/var/tmp/sosreport-my-cluster-node-01234567-2020-05-28-eyjknxt.tar.xz 1 The checksum is: 382ffc167510fd71b4f12a4f40b97a4e
- 1
- The
sosreport
archive’s file path is outside of thechroot
environment because the toolbox container mounts the host’s root directory at/host
.
Provide the
sosreport
archive to Red Hat Support for analysis, using one of the following methods.Upload the file to an existing Red Hat support case directly from an OpenShift Container Platform cluster.
From within the toolbox container, run
redhat-support-tool
to attach the archive directly to an existing Red Hat support case. This example uses support case ID01234567
:# redhat-support-tool addattachment -c 01234567 /host/var/tmp/my-sosreport.tar.xz 1
- 1
- The toolbox container mounts the host’s root directory at
/host
. Reference the absolute path from the toolbox container’s root directory, including/host/
, when specifying files to upload through theredhat-support-tool
command.
Upload the file to an existing Red Hat support case.
Concatenate the
sosreport
archive by running theoc debug node/<node_name>
command and redirect the output to a file. This command assumes you have exited the previousoc debug
session:$ oc debug node/my-cluster-node -- bash -c 'cat /host/var/tmp/sosreport-my-cluster-node-01234567-2020-05-28-eyjknxt.tar.xz' > /tmp/sosreport-my-cluster-node-01234567-2020-05-28-eyjknxt.tar.xz 1
- 1
- The debug container mounts the host’s root directory at
/host
. Reference the absolute path from the debug container’s root directory, including/host
, when specifying target files for concatenation.
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Transferring a
sosreport
archive from a cluster node by usingscp
is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to copy asosreport
archive from a node by runningscp core@<node>.<cluster_name>.<base_domain>:<file_path> <local_path>
.- Navigate to an existing support case within https://access.redhat.com/support/cases/.
- Select Attach files and follow the prompts to upload the file.
5.5. Querying bootstrap node journal logs
If you experience bootstrap-related issues, you can gather bootkube.service
journald
unit logs and container logs from the bootstrap node.
Prerequisites
- You have SSH access to your bootstrap node.
- You have the fully qualified domain name of the bootstrap node.
Procedure
Query
bootkube.service
journald
unit logs from a bootstrap node during OpenShift Container Platform installation. Replace<bootstrap_fqdn>
with the bootstrap node’s fully qualified domain name:$ ssh core@<bootstrap_fqdn> journalctl -b -f -u bootkube.service
NoteThe
bootkube.service
log on the bootstrap node outputs etcdconnection refused
errors, indicating that the bootstrap server is unable to connect to etcd on control plane nodes (also known as the master nodes). After etcd has started on each control plane node and the nodes have joined the cluster, the errors should stop.Collect logs from the bootstrap node containers using
podman
on the bootstrap node. Replace<bootstrap_fqdn>
with the bootstrap node’s fully qualified domain name:$ ssh core@<bootstrap_fqdn> 'for pod in $(sudo podman ps -a -q); do sudo podman logs $pod; done'
5.6. Querying cluster node journal logs
You can gather journald
unit logs and other logs within /var/log
on individual cluster nodes.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
). - You have SSH access to your hosts.
Procedure
Query
kubelet
journald
unit logs from OpenShift Container Platform cluster nodes. The following example queries control plane nodes (also known as the master nodes) only:$ oc adm node-logs --role=master -u kubelet 1
- 1
- Replace
kubelet
as appropriate to query other unit logs.
Collect logs from specific subdirectories under
/var/log/
on cluster nodes.Retrieve a list of logs contained within a
/var/log/
subdirectory. The following example lists files in/var/log/openshift-apiserver/
on all control plane nodes:$ oc adm node-logs --role=master --path=openshift-apiserver
Inspect a specific log within a
/var/log/
subdirectory. The following example outputs/var/log/openshift-apiserver/audit.log
contents from all control plane nodes:$ oc adm node-logs --role=master --path=openshift-apiserver/audit.log
If the API is not functional, review the logs on each node using SSH instead. The following example tails
/var/log/openshift-apiserver/audit.log
:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo tail -f /var/log/openshift-apiserver/audit.log
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. Before attempting to collect diagnostic data over SSH, review whether the data collected by running
oc adm must gather
and otheroc
commands is sufficient instead. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
.
5.7. Collecting a network trace from an OpenShift Container Platform node or container
When investigating potential network-related OpenShift Container Platform issues, Red Hat Support might request a network packet trace from a specific OpenShift Container Platform cluster node or from a specific container. The recommended method to capture a network trace in OpenShift Container Platform is through a debug pod.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
). - You have a Red Hat standard or premium Subscription.
- You have a Red Hat Customer Portal account.
- You have an existing Red Hat Support case ID.
- You have SSH access to your hosts.
Procedure
Obtain a list of cluster nodes:
$ oc get nodes
Enter into a debug session on the target node. This step instantiates a debug pod called
<node_name>-debug
:$ oc debug node/my-cluster-node
Set
/host
as the root directory within the debug shell. The debug pod mounts the host’s root file system in/host
within the pod. By changing the root directory to/host
, you can run binaries contained in the host’s executable paths:# chroot /host
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,
oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
instead.From within the
chroot
environment console, obtain the node’s interface names:# ip ad
Start a
toolbox
container, which includes the required binaries and plugins to runsosreport
:# toolbox
NoteIf an existing
toolbox
pod is already running, thetoolbox
command outputs'toolbox-' already exists. Trying to start…
. To avoidtcpdump
issues, remove the running toolbox container withpodman rm toolbox-
and spawn a new toolbox container.Initiate a
tcpdump
session on the cluster node and redirect output to a capture file. This example usesens5
as the interface name:$ tcpdump -nn -s 0 -i ens5 -w /host/var/tmp/my-cluster-node_$(date +%d_%m_%Y-%H_%M_%S-%Z).pcap 1
- 1
- The
tcpdump
capture file’s path is outside of thechroot
environment because the toolbox container mounts the host’s root directory at/host
.
If a
tcpdump
capture is required for a specific container on the node, follow these steps.Determine the target container ID. The
chroot host
command precedes thecrictl
command in this step because the toolbox container mounts the host’s root directory at/host
:# chroot /host crictl ps
Determine the container’s process ID. In this example, the container ID is
a7fe32346b120
:# chroot /host crictl inspect --output yaml a7fe32346b120 | grep 'pid' | awk '{print $2}'
Initiate a
tcpdump
session on the container and redirect output to a capture file. This example uses49628
as the container’s process ID andens5
as the interface name. Thensenter
command enters the namespace of a target process and runs a command in its namespace. because the target process in this example is a container’s process ID, thetcpdump
command is run in the container’s namespace from the host:# nsenter -n -t 49628 -- tcpdump -nn -i ens5 -w /host/var/tmp/my-cluster-node-my-container_$(date +%d_%m_%Y-%H_%M_%S-%Z).pcap.pcap 1
- 1
- The
tcpdump
capture file’s path is outside of thechroot
environment because the toolbox container mounts the host’s root directory at/host
.
Provide the
tcpdump
capture file to Red Hat Support for analysis, using one of the following methods.Upload the file to an existing Red Hat support case directly from an OpenShift Container Platform cluster.
From within the toolbox container, run
redhat-support-tool
to attach the file directly to an existing Red Hat Support case. This example uses support case ID01234567
:# redhat-support-tool addattachment -c 01234567 /host/var/tmp/my-tcpdump-capture-file.pcap 1
- 1
- The toolbox container mounts the host’s root directory at
/host
. Reference the absolute path from the toolbox container’s root directory, including/host/
, when specifying files to upload through theredhat-support-tool
command.
Upload the file to an existing Red Hat support case.
Concatenate the
sosreport
archive by running theoc debug node/<node_name>
command and redirect the output to a file. This command assumes you have exited the previousoc debug
session:$ oc debug node/my-cluster-node -- bash -c 'cat /host/var/tmp/my-tcpdump-capture-file.pcap' > /tmp/my-tcpdump-capture-file.pcap 1
- 1
- The debug container mounts the host’s root directory at
/host
. Reference the absolute path from the debug container’s root directory, including/host
, when specifying target files for concatenation.
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Transferring a
tcpdump
capture file from a cluster node by usingscp
is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to copy atcpdump
capture file from a node by runningscp core@<node>.<cluster_name>.<base_domain>:<file_path> <local_path>
.- Navigate to an existing support case within https://access.redhat.com/support/cases/.
- Select Attach files and follow the prompts to upload the file.
5.8. Providing diagnostic data to Red Hat Support
When investigating OpenShift Container Platform issues, Red Hat Support might ask you to upload diagnostic data to a support case. Files can be uploaded to a support case through the Red Hat Customer Portal, or from an OpenShift Container Platform cluster directly by using the redhat-support-tool
command.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - You have SSH access to your hosts.
-
You have installed the OpenShift CLI (
oc
). - You have a Red Hat standard or premium Subscription.
- You have a Red Hat Customer Portal account.
- You have an existing Red Hat Support case ID.
Procedure
Upload diagnostic data to an existing Red Hat support case through the Red Hat Customer Portal.
Concatenate a diagnostic file contained on an OpenShift Container Platform node by using the
oc debug node/<node_name>
command and redirect the output to a file. The following example copies/host/var/tmp/my-diagnostic-data.tar.gz
from a debug container to/var/tmp/my-diagnostic-data.tar.gz
:$ oc debug node/my-cluster-node -- bash -c 'cat /host/var/tmp/my-diagnostic-data.tar.gz' > /var/tmp/my-diagnostic-data.tar.gz 1
- 1
- The debug container mounts the host’s root directory at
/host
. Reference the absolute path from the debug container’s root directory, including/host
, when specifying target files for concatenation.
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Transferring files from a cluster node by using
scp
is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to copy diagnostic files from a node by runningscp core@<node>.<cluster_name>.<base_domain>:<file_path> <local_path>
.- Navigate to an existing support case within https://access.redhat.com/support/cases/.
- Select Attach files and follow the prompts to upload the file.
Upload diagnostic data to an existing Red Hat support case directly from an OpenShift Container Platform cluster.
Obtain a list of cluster nodes:
$ oc get nodes
Enter into a debug session on the target node. This step instantiates a debug pod called
<node_name>-debug
:$ oc debug node/my-cluster-node
Set
/host
as the root directory within the debug shell. The debug pod mounts the host’s root file system in/host
within the pod. By changing the root directory to/host
, you can run binaries contained in the host’s executable paths:# chroot /host
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,
oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
instead.Start a
toolbox
container, which includes the required binaries to runredhat-support-tool
:# toolbox
NoteIf an existing
toolbox
pod is already running, thetoolbox
command outputs'toolbox-' already exists. Trying to start…
. Remove the running toolbox container withpodman rm toolbox-
and spawn a new toolbox container, to avoid issues.Run
redhat-support-tool
to attach a file from the debug pod directly to an existing Red Hat Support case. This example uses support case ID '01234567' and example file path/host/var/tmp/my-diagnostic-data.tar.gz
:# redhat-support-tool addattachment -c 01234567 /host/var/tmp/my-diagnostic-data.tar.gz 1
- 1
- The toolbox container mounts the host’s root directory at
/host
. Reference the absolute path from the toolbox container’s root directory, including/host/
, when specifying files to upload through theredhat-support-tool
command.
5.9. About toolbox
toolbox
is a tool that starts a container on a Red Hat Enterprise Linux CoreOS (RHCOS) system. The tool is primarily used to start a container that includes the required binaries and plugins that are needed to run commands such as sosreport
and redhat-support-tool
.
The primary purpose for a toolbox
container is to gather diagnostic information and to provide it to Red Hat Support. However, if additional diagnostic tools are required, you can add RPM packages or run an image that is an alternative to the standard support tools image.
Installing packages to a toolbox
container
By default, running the toolbox
command starts a container with the registry.redhat.io/rhel8/support-tools:latest
image. This image contains the most frequently used support tools. If you need to collect node-specific data that requires a support tool that is not part of the image, you can install additional packages.
Prerequisites
-
You have accessed a node with the
oc debug node/<node_name>
command.
Procedure
Set
/host
as the root directory within the debug shell. The debug pod mounts the host’s root file system in/host
within the pod. By changing the root directory to/host
, you can run binaries contained in the host’s executable paths:# chroot /host
Start the toolbox container:
# toolbox
Install the additional package, such as
wget
:# dnf install -y <package_name>
Starting an alternative image with toolbox
By default, running the toolbox
command starts a container with the registry.redhat.io/rhel8/support-tools:latest
image. You can start an alternative image by creating a .toolboxrc
file and specifying the image to run.
Prerequisites
-
You have accessed a node with the
oc debug node/<node_name>
command.
Procedure
Set
/host
as the root directory within the debug shell. The debug pod mounts the host’s root file system in/host
within the pod. By changing the root directory to/host
, you can run binaries contained in the host’s executable paths:# chroot /host
Create a
.toolboxrc
file in the home directory for the root user ID:# vi ~/.toolboxrc
REGISTRY=quay.io 1 IMAGE=fedora/fedora:33-x86_64 2 TOOLBOX_NAME=toolbox-fedora-33 3
Start a toolbox container with the alternative image:
# toolbox
NoteIf an existing
toolbox
pod is already running, thetoolbox
command outputs'toolbox-' already exists. Trying to start…
. Remove the running toolbox container withpodman rm toolbox-
and spawn a new toolbox container, to avoid issues withsosreport
plugins.
Chapter 6. Summarizing cluster specifications
6.1. Summarizing cluster specifications through clusterversion
You can obtain a summary of OpenShift Container Platform cluster specifications by querying the clusterversion
resource.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
Query cluster version, availability, uptime, and general status:
$ oc get clusterversion
Obtain a detailed summary of cluster specifications, update availability, and update history:
$ oc describe clusterversion
Chapter 7. Troubleshooting
7.1. Troubleshooting installations
7.1.1. Determining where installation issues occur
When troubleshooting OpenShift Container Platform installation issues, you can monitor installation logs to determine at which stage issues occur. Then, retrieve diagnostic data relevant to that stage.
OpenShift Container Platform installation proceeds through the following stages:
- Ignition configuration files are created.
- The bootstrap machine boots and starts hosting the remote resources required for the control plane machines (also known as the master machines) to boot.
- The control plane machines fetch the remote resources from the bootstrap machine and finish booting.
- The control plane machines use the bootstrap machine to form an etcd cluster.
- The bootstrap machine starts a temporary Kubernetes control plane using the new etcd cluster.
- The temporary control plane schedules the production control plane to the control plane machines.
- The temporary control plane shuts down and passes control to the production control plane.
- The bootstrap machine adds OpenShift Container Platform components into the production control plane.
- The installation program shuts down the bootstrap machine.
- The control plane sets up the worker nodes.
- The control plane installs additional services in the form of a set of Operators.
- The cluster downloads and configures remaining components needed for the day-to-day operation, including the creation of worker machines in supported environments.
7.1.2. User-provisioned infrastructure installation considerations
The default installation method uses installer-provisioned infrastructure. With installer-provisioned infrastructure clusters, OpenShift Container Platform manages all aspects of the cluster, including the operating system itself. If possible, use this feature to avoid having to provision and maintain the cluster infrastructure.
You can alternatively install OpenShift Container Platform 4.8 on infrastructure that you provide. If you use this installation method, follow user-provisioned infrastructure installation documentation carefully. Additionally, review the following considerations before the installation:
- Check the Red Hat Enterprise Linux (RHEL) Ecosystem to determine the level of Red Hat Enterprise Linux CoreOS (RHCOS) support provided for your chosen server hardware or virtualization technology.
- Many virtualization and cloud environments require agents to be installed on guest operating systems. Ensure that these agents are installed as a containerized workload deployed through a daemon set.
Install cloud provider integration if you want to enable features such as dynamic storage, on-demand service routing, node hostname to Kubernetes hostname resolution, and cluster autoscaling.
NoteIt is not possible to enable cloud provider integration in OpenShift Container Platform environments that mix resources from different cloud providers, or that span multiple physical or virtual platforms. The node life cycle controller will not allow nodes that are external to the existing provider to be added to a cluster, and it is not possible to specify more than one cloud provider integration.
- A provider-specific Machine API implementation is required if you want to use machine sets or autoscaling to automatically provision OpenShift Container Platform cluster nodes.
- Check whether your chosen cloud provider offers a method to inject Ignition configuration files into hosts as part of their initial deployment. If they do not, you will need to host Ignition configuration files by using an HTTP server. The steps taken to troubleshoot Ignition configuration file issues will differ depending on which of these two methods is deployed.
- Storage needs to be manually provisioned if you want to leverage optional framework components such as the embedded container registry, Elasticsearch, or Prometheus. Default storage classes are not defined in user-provisioned infrastructure installations unless explicitly configured.
- A load balancer is required to distribute API requests across all control plane nodes (also known as the master nodes) in highly available OpenShift Container Platform environments. You can use any TCP-based load balancing solution that meets OpenShift Container Platform DNS routing and port requirements.
7.1.3. Checking a load balancer configuration before OpenShift Container Platform installation
Check your load balancer configuration prior to starting an OpenShift Container Platform installation.
Prerequisites
- You have configured an external load balancer of your choosing, in preparation for an OpenShift Container Platform installation. The following example is based on a Red Hat Enterprise Linux (RHEL) host using HAProxy to provide load balancing services to a cluster.
- You have configured DNS in preparation for an OpenShift Container Platform installation.
- You have SSH access to your load balancer.
Procedure
Check that the
haproxy
systemd service is active:$ ssh <user_name>@<load_balancer> systemctl status haproxy
Verify that the load balancer is listening on the required ports. The following example references ports
80
,443
,6443
, and22623
.For HAProxy instances running on Red Hat Enterprise Linux (RHEL) 6, verify port status by using the
netstat
command:$ ssh <user_name>@<load_balancer> netstat -nltupe | grep -E ':80|:443|:6443|:22623'
For HAProxy instances running on Red Hat Enterprise Linux (RHEL) 7 or 8, verify port status by using the
ss
command:$ ssh <user_name>@<load_balancer> ss -nltupe | grep -E ':80|:443|:6443|:22623'
NoteRed Hat recommends the
ss
command instead ofnetstat
in Red Hat Enterprise Linux (RHEL) 7 or later.ss
is provided by the iproute package. For more information on thess
command, see the Red Hat Enterprise Linux (RHEL) 7 Performance Tuning Guide.
Check that the wildcard DNS record resolves to the load balancer:
$ dig <wildcard_fqdn> @<dns_server>
7.1.4. Specifying OpenShift Container Platform installer log levels
By default, the OpenShift Container Platform installer log level is set to info
. If more detailed logging is required when diagnosing a failed OpenShift Container Platform installation, you can increase the openshift-install
log level to debug
when starting the installation again.
Prerequisites
- You have access to the installation host.
Procedure
Set the installation log level to
debug
when initiating the installation:$ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete --log-level debug 1
- 1
- Possible log levels include
info
,warn
,error,
anddebug
.
7.1.5. Troubleshooting openshift-install command issues
If you experience issues running the openshift-install
command, check the following:
The installation has been initiated within 24 hours of Ignition configuration file creation. The Ignition files are created when the following command is run:
$ ./openshift-install create ignition-configs --dir=./install_dir
-
The
install-config.yaml
file is in the same directory as the installer. If an alternative installation path is declared by using the./openshift-install --dir
option, verify that theinstall-config.yaml
file exists within that directory.
7.1.6. Monitoring installation progress
You can monitor high-level installation, bootstrap, and control plane logs as an OpenShift Container Platform installation progresses. This provides greater visibility into how an installation progresses and helps identify the stage at which an installation failure occurs.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
). - You have SSH access to your hosts.
You have the fully qualified domain names of the bootstrap and control plane nodes (also known as the master nodes).
NoteThe initial
kubeadmin
password can be found in<install_directory>/auth/kubeadmin-password
on the installation host.
Procedure
Watch the installation log as the installation progresses:
$ tail -f ~/<installation_directory>/.openshift_install.log
Monitor the
bootkube.service
journald unit log on the bootstrap node, after it has booted. This provides visibility into the bootstrapping of the first control plane. Replace<bootstrap_fqdn>
with the bootstrap node’s fully qualified domain name:$ ssh core@<bootstrap_fqdn> journalctl -b -f -u bootkube.service
NoteThe
bootkube.service
log on the bootstrap node outputs etcdconnection refused
errors, indicating that the bootstrap server is unable to connect to etcd on control plane nodes. After etcd has started on each control plane node and the nodes have joined the cluster, the errors should stop.Monitor
kubelet.service
journald unit logs on control plane nodes, after they have booted. This provides visibility into control plane node agent activity.Monitor the logs using
oc
:$ oc adm node-logs --role=master -u kubelet
If the API is not functional, review the logs using SSH instead. Replace
<master-node>.<cluster_name>.<base_domain>
with appropriate values:$ ssh core@<master-node>.<cluster_name>.<base_domain> journalctl -b -f -u kubelet.service
Monitor
crio.service
journald unit logs on control plane nodes, after they have booted. This provides visibility into control plane node CRI-O container runtime activity.Monitor the logs using
oc
:$ oc adm node-logs --role=master -u crio
If the API is not functional, review the logs using SSH instead. Replace
<master-node>.<cluster_name>.<base_domain>
with appropriate values:$ ssh core@master-N.cluster_name.sub_domain.domain journalctl -b -f -u crio.service
7.1.7. Gathering bootstrap node diagnostic data
When experiencing bootstrap-related issues, you can gather bootkube.service
journald
unit logs and container logs from the bootstrap node.
Prerequisites
- You have SSH access to your bootstrap node.
- You have the fully qualified domain name of the bootstrap node.
- If you are hosting Ignition configuration files by using an HTTP server, you must have the HTTP server’s fully qualified domain name and the port number. You must also have SSH access to the HTTP host.
Procedure
- If you have access to the bootstrap node’s console, monitor the console until the node reaches the login prompt.
Verify the Ignition file configuration.
If you are hosting Ignition configuration files by using an HTTP server.
Verify the bootstrap node Ignition file URL. Replace
<http_server_fqdn>
with HTTP server’s fully qualified domain name:$ curl -I http://<http_server_fqdn>:<port>/bootstrap.ign 1
- 1
- The
-I
option returns the header only. If the Ignition file is available on the specified URL, the command returns200 OK
status. If it is not available, the command returns404 file not found
.
To verify that the Ignition file was received by the bootstrap node, query the HTTP server logs on the serving host. For example, if you are using an Apache web server to serve Ignition files, enter the following command:
$ grep -is 'bootstrap.ign' /var/log/httpd/access_log
If the bootstrap Ignition file is received, the associated
HTTP GET
log message will include a200 OK
success status, indicating that the request succeeded.- If the Ignition file was not received, check that the Ignition files exist and that they have the appropriate file and web server permissions on the serving host directly.
If you are using a cloud provider mechanism to inject Ignition configuration files into hosts as part of their initial deployment.
- Review the bootstrap node’s console to determine if the mechanism is injecting the bootstrap node Ignition file correctly.
- Verify the availability of the bootstrap node’s assigned storage device.
- Verify that the bootstrap node has been assigned an IP address from the DHCP server.
Collect
bootkube.service
journald unit logs from the bootstrap node. Replace<bootstrap_fqdn>
with the bootstrap node’s fully qualified domain name:$ ssh core@<bootstrap_fqdn> journalctl -b -f -u bootkube.service
NoteThe
bootkube.service
log on the bootstrap node outputs etcdconnection refused
errors, indicating that the bootstrap server is unable to connect to etcd on control plane nodes (also known as the master nodes). After etcd has started on each control plane node and the nodes have joined the cluster, the errors should stop.Collect logs from the bootstrap node containers.
Collect the logs using
podman
on the bootstrap node. Replace<bootstrap_fqdn>
with the bootstrap node’s fully qualified domain name:$ ssh core@<bootstrap_fqdn> 'for pod in $(sudo podman ps -a -q); do sudo podman logs $pod; done'
If the bootstrap process fails, verify the following.
-
You can resolve
api.<cluster_name>.<base_domain>
from the installation host. - The load balancer proxies port 6443 connections to bootstrap and control plane nodes. Ensure that the proxy configuration meets OpenShift Container Platform installation requirements.
-
You can resolve
7.1.8. Investigating control plane node installation issues
If you experience control plane node (also known as the master node)installation issues, determine the control plane node OpenShift Container Platform software defined network (SDN), and network Operator status. Collect kubelet.service
, crio.service
journald unit logs, and control plane node container logs for visibility into control plane node agent, CRI-O container runtime, and pod activity.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
). - You have SSH access to your hosts.
- You have the fully qualified domain names of the bootstrap and control plane nodes.
If you are hosting Ignition configuration files by using an HTTP server, you must have the HTTP server’s fully qualified domain name and the port number. You must also have SSH access to the HTTP host.
NoteThe initial
kubeadmin
password can be found in<install_directory>/auth/kubeadmin-password
on the installation host.
Procedure
- If you have access to the console for the control plane node, monitor the console until the node reaches the login prompt. During the installation, Ignition log messages are output to the console.
Verify Ignition file configuration.
If you are hosting Ignition configuration files by using an HTTP server.
Verify the control plane node Ignition file URL. Replace
<http_server_fqdn>
with HTTP server’s fully qualified domain name:$ curl -I http://<http_server_fqdn>:<port>/master.ign 1
- 1
- The
-I
option returns the header only. If the Ignition file is available on the specified URL, the command returns200 OK
status. If it is not available, the command returns404 file not found
.
To verify that the Ignition file was received by the control plane node query the HTTP server logs on the serving host. For example, if you are using an Apache web server to serve Ignition files:
$ grep -is 'master.ign' /var/log/httpd/access_log
If the master Ignition file is received, the associated
HTTP GET
log message will include a200 OK
success status, indicating that the request succeeded.- If the Ignition file was not received, check that it exists on the serving host directly. Ensure that the appropriate file and web server permissions are in place.
If you are using a cloud provider mechanism to inject Ignition configuration files into hosts as part of their initial deployment.
- Review the console for the control plane node to determine if the mechanism is injecting the control plane node Ignition file correctly.
- Check the availability of the storage device assigned to the control plane node.
- Verify that the control plane node has been assigned an IP address from the DHCP server.
Determine control plane node status.
Query control plane node status:
$ oc get nodes
If one of the control plane nodes does not reach a
Ready
status, retrieve a detailed node description:$ oc describe node <master_node>
NoteIt is not possible to run
oc
commands if an installation issue prevents the OpenShift Container Platform API from running or if the kubelet is not running yet on each node:
Determine OpenShift Container Platform SDN status.
Review
sdn-controller
,sdn
, andovs
daemon set status, in theopenshift-sdn
namespace:$ oc get daemonsets -n openshift-sdn
If those resources are listed as
Not found
, review pods in theopenshift-sdn
namespace:$ oc get pods -n openshift-sdn
Review logs relating to failed OpenShift Container Platform SDN pods in the
openshift-sdn
namespace:$ oc logs <sdn_pod> -n openshift-sdn
Determine cluster network configuration status.
Review whether the cluster’s network configuration exists:
$ oc get network.config.openshift.io cluster -o yaml
If the installer failed to create the network configuration, generate the Kubernetes manifests again and review message output:
$ ./openshift-install create manifests
Review the pod status in the
openshift-network-operator
namespace to determine whether the Cluster Network Operator (CNO) is running:$ oc get pods -n openshift-network-operator
Gather network Operator pod logs from the
openshift-network-operator
namespace:$ oc logs pod/<network_operator_pod_name> -n openshift-network-operator
Monitor
kubelet.service
journald unit logs on control plane nodes, after they have booted. This provides visibility into control plane node agent activity.Retrieve the logs using
oc
:$ oc adm node-logs --role=master -u kubelet
If the API is not functional, review the logs using SSH instead. Replace
<master-node>.<cluster_name>.<base_domain>
with appropriate values:$ ssh core@<master-node>.<cluster_name>.<base_domain> journalctl -b -f -u kubelet.service
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. Before attempting to collect diagnostic data over SSH, review whether the data collected by running
oc adm must gather
and otheroc
commands is sufficient instead. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
.
Retrieve
crio.service
journald unit logs on control plane nodes, after they have booted. This provides visibility into control plane node CRI-O container runtime activity.Retrieve the logs using
oc
:$ oc adm node-logs --role=master -u crio
If the API is not functional, review the logs using SSH instead:
$ ssh core@<master-node>.<cluster_name>.<base_domain> journalctl -b -f -u crio.service
Collect logs from specific subdirectories under
/var/log/
on control plane nodes.Retrieve a list of logs contained within a
/var/log/
subdirectory. The following example lists files in/var/log/openshift-apiserver/
on all control plane nodes:$ oc adm node-logs --role=master --path=openshift-apiserver
Inspect a specific log within a
/var/log/
subdirectory. The following example outputs/var/log/openshift-apiserver/audit.log
contents from all control plane nodes:$ oc adm node-logs --role=master --path=openshift-apiserver/audit.log
If the API is not functional, review the logs on each node using SSH instead. The following example tails
/var/log/openshift-apiserver/audit.log
:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo tail -f /var/log/openshift-apiserver/audit.log
Review control plane node container logs using SSH.
List the containers:
$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl ps -a
Retrieve a container’s logs using
crictl
:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl logs -f <container_id>
If you experience control plane node configuration issues, verify that the MCO, MCO endpoint, and DNS record are functioning. The Machine Config Operator (MCO) manages operating system configuration during the installation procedure. Also verify system clock accuracy and certificate validity.
Test whether the MCO endpoint is available. Replace
<cluster_name>
with appropriate values:$ curl https://api-int.<cluster_name>:22623/config/master
- If the endpoint is unresponsive, verify load balancer configuration. Ensure that the endpoint is configured to run on port 22623.
Verify that the MCO endpoint’s DNS record is configured and resolves to the load balancer.
Run a DNS lookup for the defined MCO endpoint name:
$ dig api-int.<cluster_name> @<dns_server>
Run a reverse lookup to the assigned MCO IP address on the load balancer:
$ dig -x <load_balancer_mco_ip_address> @<dns_server>
Verify that the MCO is functioning from the bootstrap node directly. Replace
<bootstrap_fqdn>
with the bootstrap node’s fully qualified domain name:$ ssh core@<bootstrap_fqdn> curl https://api-int.<cluster_name>:22623/config/master
System clock time must be synchronized between bootstrap, master, and worker nodes. Check each node’s system clock reference time and time synchronization statistics:
$ ssh core@<node>.<cluster_name>.<base_domain> chronyc tracking
Review certificate validity:
$ openssl s_client -connect api-int.<cluster_name>:22623 | openssl x509 -noout -text
7.1.9. Investigating etcd installation issues
If you experience etcd issues during installation, you can check etcd pod status and collect etcd pod logs. You can also verify etcd DNS records and check DNS availability on control plane nodes (also known as the master nodes).
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
). - You have SSH access to your hosts.
- You have the fully qualified domain names of the control plane nodes.
Procedure
Check the status of etcd pods.
Review the status of pods in the
openshift-etcd
namespace:$ oc get pods -n openshift-etcd
Review the status of pods in the
openshift-etcd-operator
namespace:$ oc get pods -n openshift-etcd-operator
If any of the pods listed by the previous commands are not showing a
Running
or aCompleted
status, gather diagnostic information for the pod.Review events for the pod:
$ oc describe pod/<pod_name> -n <namespace>
Inspect the pod’s logs:
$ oc logs pod/<pod_name> -n <namespace>
If the pod has more than one container, the preceding command will create an error, and the container names will be provided in the error message. Inspect logs for each container:
$ oc logs pod/<pod_name> -c <container_name> -n <namespace>
If the API is not functional, review etcd pod and container logs on each control plane node by using SSH instead. Replace
<master-node>.<cluster_name>.<base_domain>
with appropriate values.List etcd pods on each control plane node:
$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl pods --name=etcd-
For any pods not showing
Ready
status, inspect pod status in detail. Replace<pod_id>
with the pod’s ID listed in the output of the preceding command:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl inspectp <pod_id>
List containers related to a pod:
$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl ps | grep '<pod_id>'
For any containers not showing
Ready
status, inspect container status in detail. Replace<container_id>
with container IDs listed in the output of the preceding command:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl inspect <container_id>
Review the logs for any containers not showing a
Ready
status. Replace<container_id>
with the container IDs listed in the output of the preceding command:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl logs -f <container_id>
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. Before attempting to collect diagnostic data over SSH, review whether the data collected by running
oc adm must gather
and otheroc
commands is sufficient instead. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
.
- Validate primary and secondary DNS server connectivity from control plane nodes.
7.1.10. Investigating control plane node kubelet and API server issues
To investigate control plane node (also known as the master node) kubelet and API server issues during installation, check DNS, DHCP, and load balancer functionality. Also, verify that certificates have not expired.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
). - You have SSH access to your hosts.
- You have the fully qualified domain names of the control plane nodes.
Procedure
-
Verify that the API server’s DNS record directs the kubelet on control plane nodes to
https://api-int.<cluster_name>.<base_domain>:6443
. Ensure that the record references the load balancer. - Ensure that the load balancer’s port 6443 definition references each control plane node.
- Check that unique control plane node hostnames have been provided by DHCP.
Inspect the
kubelet.service
journald unit logs on each control plane node.Retrieve the logs using
oc
:$ oc adm node-logs --role=master -u kubelet
If the API is not functional, review the logs using SSH instead. Replace
<master-node>.<cluster_name>.<base_domain>
with appropriate values:$ ssh core@<master-node>.<cluster_name>.<base_domain> journalctl -b -f -u kubelet.service
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. Before attempting to collect diagnostic data over SSH, review whether the data collected by running
oc adm must gather
and otheroc
commands is sufficient instead. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
.
Check for certificate expiration messages in the control plane node kubelet logs.
Retrieve the log using
oc
:$ oc adm node-logs --role=master -u kubelet | grep -is 'x509: certificate has expired'
If the API is not functional, review the logs using SSH instead. Replace
<master-node>.<cluster_name>.<base_domain>
with appropriate values:$ ssh core@<master-node>.<cluster_name>.<base_domain> journalctl -b -f -u kubelet.service | grep -is 'x509: certificate has expired'
7.1.11. Investigating worker node installation issues
If you experience worker node installation issues, you can review the worker node status. Collect kubelet.service
, crio.service
journald unit logs and the worker node container logs for visibility into the worker node agent, CRI-O container runtime and pod activity. Additionally, you can check the Ignition file and Machine API Operator functionality. If worker node post-installation configuration fails, check Machine Config Operator (MCO) and DNS functionality. You can also verify system clock synchronization between the bootstrap, master, and worker nodes, and validate certificates.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
). - You have SSH access to your hosts.
- You have the fully qualified domain names of the bootstrap and worker nodes.
If you are hosting Ignition configuration files by using an HTTP server, you must have the HTTP server’s fully qualified domain name and the port number. You must also have SSH access to the HTTP host.
NoteThe initial
kubeadmin
password can be found in<install_directory>/auth/kubeadmin-password
on the installation host.
Procedure
- If you have access to the worker node’s console, monitor the console until the node reaches the login prompt. During the installation, Ignition log messages are output to the console.
Verify Ignition file configuration.
If you are hosting Ignition configuration files by using an HTTP server.
Verify the worker node Ignition file URL. Replace
<http_server_fqdn>
with HTTP server’s fully qualified domain name:$ curl -I http://<http_server_fqdn>:<port>/worker.ign 1
- 1
- The
-I
option returns the header only. If the Ignition file is available on the specified URL, the command returns200 OK
status. If it is not available, the command returns404 file not found
.
To verify that the Ignition file was received by the worker node, query the HTTP server logs on the HTTP host. For example, if you are using an Apache web server to serve Ignition files:
$ grep -is 'worker.ign' /var/log/httpd/access_log
If the worker Ignition file is received, the associated
HTTP GET
log message will include a200 OK
success status, indicating that the request succeeded.- If the Ignition file was not received, check that it exists on the serving host directly. Ensure that the appropriate file and web server permissions are in place.
If you are using a cloud provider mechanism to inject Ignition configuration files into hosts as part of their initial deployment.
- Review the worker node’s console to determine if the mechanism is injecting the worker node Ignition file correctly.
- Check the availability of the worker node’s assigned storage device.
- Verify that the worker node has been assigned an IP address from the DHCP server.
Determine worker node status.
Query node status:
$ oc get nodes
Retrieve a detailed node description for any worker nodes not showing a
Ready
status:$ oc describe node <worker_node>
NoteIt is not possible to run
oc
commands if an installation issue prevents the OpenShift Container Platform API from running or if the kubelet is not running yet on each node.
Unlike control plane nodes (also known as the master nodes), worker nodes are deployed and scaled using the Machine API Operator. Check the status of the Machine API Operator.
Review Machine API Operator pod status:
$ oc get pods -n openshift-machine-api
If the Machine API Operator pod does not have a
Ready
status, detail the pod’s events:$ oc describe pod/<machine_api_operator_pod_name> -n openshift-machine-api
Inspect
machine-api-operator
container logs. The container runs within themachine-api-operator
pod:$ oc logs pod/<machine_api_operator_pod_name> -n openshift-machine-api -c machine-api-operator
Also inspect
kube-rbac-proxy
container logs. The container also runs within themachine-api-operator
pod:$ oc logs pod/<machine_api_operator_pod_name> -n openshift-machine-api -c kube-rbac-proxy
Monitor
kubelet.service
journald unit logs on worker nodes, after they have booted. This provides visibility into worker node agent activity.Retrieve the logs using
oc
:$ oc adm node-logs --role=worker -u kubelet
If the API is not functional, review the logs using SSH instead. Replace
<worker-node>.<cluster_name>.<base_domain>
with appropriate values:$ ssh core@<worker-node>.<cluster_name>.<base_domain> journalctl -b -f -u kubelet.service
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. Before attempting to collect diagnostic data over SSH, review whether the data collected by running
oc adm must gather
and otheroc
commands is sufficient instead. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
.
Retrieve
crio.service
journald unit logs on worker nodes, after they have booted. This provides visibility into worker node CRI-O container runtime activity.Retrieve the logs using
oc
:$ oc adm node-logs --role=worker -u crio
If the API is not functional, review the logs using SSH instead:
$ ssh core@<worker-node>.<cluster_name>.<base_domain> journalctl -b -f -u crio.service
Collect logs from specific subdirectories under
/var/log/
on worker nodes.Retrieve a list of logs contained within a
/var/log/
subdirectory. The following example lists files in/var/log/sssd/
on all worker nodes:$ oc adm node-logs --role=worker --path=sssd
Inspect a specific log within a
/var/log/
subdirectory. The following example outputs/var/log/sssd/audit.log
contents from all worker nodes:$ oc adm node-logs --role=worker --path=sssd/sssd.log
If the API is not functional, review the logs on each node using SSH instead. The following example tails
/var/log/sssd/sssd.log
:$ ssh core@<worker-node>.<cluster_name>.<base_domain> sudo tail -f /var/log/sssd/sssd.log
Review worker node container logs using SSH.
List the containers:
$ ssh core@<worker-node>.<cluster_name>.<base_domain> sudo crictl ps -a
Retrieve a container’s logs using
crictl
:$ ssh core@<worker-node>.<cluster_name>.<base_domain> sudo crictl logs -f <container_id>
If you experience worker node configuration issues, verify that the MCO, MCO endpoint, and DNS record are functioning. The Machine Config Operator (MCO) manages operating system configuration during the installation procedure. Also verify system clock accuracy and certificate validity.
Test whether the MCO endpoint is available. Replace
<cluster_name>
with appropriate values:$ curl https://api-int.<cluster_name>:22623/config/worker
- If the endpoint is unresponsive, verify load balancer configuration. Ensure that the endpoint is configured to run on port 22623.
Verify that the MCO endpoint’s DNS record is configured and resolves to the load balancer.
Run a DNS lookup for the defined MCO endpoint name:
$ dig api-int.<cluster_name> @<dns_server>
Run a reverse lookup to the assigned MCO IP address on the load balancer:
$ dig -x <load_balancer_mco_ip_address> @<dns_server>
Verify that the MCO is functioning from the bootstrap node directly. Replace
<bootstrap_fqdn>
with the bootstrap node’s fully qualified domain name:$ ssh core@<bootstrap_fqdn> curl https://api-int.<cluster_name>:22623/config/worker
System clock time must be synchronized between bootstrap, master, and worker nodes. Check each node’s system clock reference time and time synchronization statistics:
$ ssh core@<node>.<cluster_name>.<base_domain> chronyc tracking
Review certificate validity:
$ openssl s_client -connect api-int.<cluster_name>:22623 | openssl x509 -noout -text
7.1.12. Querying Operator status after installation
You can check Operator status at the end of an installation. Retrieve diagnostic data for Operators that do not become available. Review logs for any Operator pods that are listed as Pending
or have an error status. Validate base images used by problematic pods.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
Check that cluster Operators are all available at the end of an installation.
$ oc get clusteroperators
Verify that all of the required certificate signing requests (CSRs) are approved. Some nodes might not move to a
Ready
status and some cluster Operators might not become available if there are pending CSRs.Check the status of the CSRs and ensure that you see a client and server request with the
Pending
orApproved
status for each machine that you added to the cluster:$ oc get csr
Example output
NAME AGE REQUESTOR CONDITION csr-8b2br 15m system:serviceaccount:openshift-machine-config-operator:node-bootstrapper Pending 1 csr-8vnps 15m system:serviceaccount:openshift-machine-config-operator:node-bootstrapper Pending csr-bfd72 5m26s system:node:ip-10-0-50-126.us-east-2.compute.internal Pending 2 csr-c57lv 5m26s system:node:ip-10-0-95-157.us-east-2.compute.internal Pending ...
In this example, two machines are joining the cluster. You might see more approved CSRs in the list.
If the CSRs were not approved, after all of the pending CSRs for the machines you added are in
Pending
status, approve the CSRs for your cluster machines:NoteBecause the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. After you approve the initial CSRs, the subsequent node client CSRs are automatically approved by the cluster
kube-controller-manager
.NoteFor clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the
oc exec
,oc rsh
, andoc logs
commands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by thenode-bootstrapper
service account in thesystem:node
orsystem:admin
groups, and confirm the identity of the node.To approve them individually, run the following command for each valid CSR:
$ oc adm certificate approve <csr_name> 1
- 1
<csr_name>
is the name of a CSR from the list of current CSRs.
To approve all pending CSRs, run the following command:
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
View Operator events:
$ oc describe clusteroperator <operator_name>
Review Operator pod status within the Operator’s namespace:
$ oc get pods -n <operator_namespace>
Obtain a detailed description for pods that do not have
Running
status:$ oc describe pod/<operator_pod_name> -n <operator_namespace>
Inspect pod logs:
$ oc logs pod/<operator_pod_name> -n <operator_namespace>
When experiencing pod base image related issues, review base image status.
Obtain details of the base image used by a problematic pod:
$ oc get pod -o "jsonpath={range .status.containerStatuses[*]}{.name}{'\t'}{.state}{'\t'}{.image}{'\n'}{end}" <operator_pod_name> -n <operator_namespace>
List base image release information:
$ oc adm release info <image_path>:<tag> --commits
7.1.13. Gathering logs from a failed installation
If you gave an SSH key to your installation program, you can gather data about your failed installation.
You use a different command to gather logs about an unsuccessful installation than to gather logs from a running cluster. If you must gather logs from a running cluster, use the oc adm must-gather
command.
Prerequisites
- Your OpenShift Container Platform installation failed before the bootstrap process finished. The bootstrap node is running and accessible through SSH.
-
The
ssh-agent
process is active on your computer, and you provided the same SSH key to both thessh-agent
process and the installation program. - If you tried to install a cluster on infrastructure that you provisioned, you must have the fully qualified domain names of the bootstrap and control plane nodes (also known as the master nodes).
Procedure
Generate the commands that are required to obtain the installation logs from the bootstrap and control plane machines:
If you used installer-provisioned infrastructure, change to the directory that contains the installation program and run the following command:
$ ./openshift-install gather bootstrap --dir <installation_directory> 1
- 1
installation_directory
is the directory you specified when you ran./openshift-install create cluster
. This directory contains the OpenShift Container Platform definition files that the installation program creates.
For installer-provisioned infrastructure, the installation program stores information about the cluster, so you do not specify the hostnames or IP addresses.
If you used infrastructure that you provisioned yourself, change to the directory that contains the installation program and run the following command:
$ ./openshift-install gather bootstrap --dir <installation_directory> \ 1 --bootstrap <bootstrap_address> \ 2 --master <master_1_address> \ 3 --master <master_2_address> \ 4 --master <master_3_address>" 5
- 1
- For
installation_directory
, specify the same directory you specified when you ran./openshift-install create cluster
. This directory contains the OpenShift Container Platform definition files that the installation program creates. - 2
<bootstrap_address>
is the fully qualified domain name or IP address of the cluster’s bootstrap machine.- 3 4 5
- For each control plane, or master, machine in your cluster, replace
<master_*_address>
with its fully qualified domain name or IP address.
NoteA default cluster contains three control plane machines. List all of your control plane machines as shown, no matter how many your cluster uses.
Example output
INFO Pulling debug logs from the bootstrap machine INFO Bootstrap gather logs captured here "<installation_directory>/log-bundle-<timestamp>.tar.gz"
If you open a Red Hat support case about your installation failure, include the compressed logs in the case.
7.1.14. Additional resources
- See Installation process for more details on OpenShift Container Platform installation types and process.
7.2. Verifying node health
7.2.1. Reviewing node status, resource usage, and configuration
Review cluster node health status, resource consumption statistics, and node logs. Additionally, query kubelet
status on individual nodes.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
List the name, status, and role for all nodes in the cluster:
$ oc get nodes
Summarize CPU and memory usage for each node within the cluster:
$ oc adm top nodes
Summarize CPU and memory usage for a specific node:
$ oc adm top node my-node
7.2.2. Querying the kubelet’s status on a node
You can review cluster node health status, resource consumption statistics, and node logs. Additionally, you can query kubelet
status on individual nodes.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
).
Procedure
The kubelet is managed using a systemd service on each node. Review the kubelet’s status by querying the
kubelet
systemd service within a debug pod.Start a debug pod for a node:
$ oc debug node/my-node
Set
/host
as the root directory within the debug shell. The debug pod mounts the host’s root file system in/host
within the pod. By changing the root directory to/host
, you can run binaries contained in the host’s executable paths:# chroot /host
NoteOpenShift Container Platform cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or
kubelet
is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
instead.Check whether the
kubelet
systemd service is active on the node:# systemctl is-active kubelet
Output a more detailed
kubelet.service
status summary:# systemctl status kubelet
7.2.3. Querying cluster node journal logs
You can gather journald
unit logs and other logs within /var/log
on individual cluster nodes.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
). - You have SSH access to your hosts.
Procedure
Query
kubelet
journald
unit logs from OpenShift Container Platform cluster nodes. The following example queries control plane nodes (also known as the master nodes) only:$ oc adm node-logs --role=master -u kubelet 1
- 1
- Replace
kubelet
as appropriate to query other unit logs.
Collect logs from specific subdirectories under
/var/log/
on cluster nodes.Retrieve a list of logs contained within a
/var/log/
subdirectory. The following example lists files in/var/log/openshift-apiserver/
on all control plane nodes:$ oc adm node-logs --role=master --path=openshift-apiserver
Inspect a specific log within a
/var/log/
subdirectory. The following example outputs/var/log/openshift-apiserver/audit.log
contents from all control plane nodes:$ oc adm node-logs --role=master --path=openshift-apiserver/audit.log
If the API is not functional, review the logs on each node using SSH instead. The following example tails
/var/log/openshift-apiserver/audit.log
:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo tail -f /var/log/openshift-apiserver/audit.log
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. Before attempting to collect diagnostic data over SSH, review whether the data collected by running
oc adm must gather
and otheroc
commands is sufficient instead. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
.
7.3. Troubleshooting CRI-O container runtime issues
7.3.1. About CRI-O container runtime engine
CRI-O is a Kubernetes-native container runtime implementation that integrates closely with the operating system to deliver an efficient and optimized Kubernetes experience. CRI-O provides facilities for running, stopping, and restarting containers.
The CRI-O container runtime engine is managed using a systemd service on each OpenShift Container Platform cluster node. When container runtime issues occur, verify the status of the crio
systemd service on each node. Gather CRI-O journald unit logs from nodes that manifest container runtime issues.
7.3.2. Verifying CRI-O runtime engine status
You can verify CRI-O container runtime engine status on each cluster node.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
Review CRI-O status by querying the
crio
systemd service on a node, within a debug pod.Start a debug pod for a node:
$ oc debug node/my-node
Set
/host
as the root directory within the debug shell. The debug pod mounts the host’s root file system in/host
within the pod. By changing the root directory to/host
, you can run binaries contained in the host’s executable paths:# chroot /host
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,
oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
instead.Check whether the
crio
systemd service is active on the node:# systemctl is-active crio
Output a more detailed
crio.service
status summary:# systemctl status crio.service
7.3.3. Gathering CRI-O journald unit logs
If you experience CRI-O issues, you can obtain CRI-O journald unit logs from a node.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
). - You have the fully qualified domain names of the control plane, or control plane machines (also known as the master machines).
Procedure
Gather CRI-O journald unit logs. The following example collects logs from all control plane nodes (within the cluster:
$ oc adm node-logs --role=master -u crio
Gather CRI-O journald unit logs from a specific node:
$ oc adm node-logs <node_name> -u crio
If the API is not functional, review the logs using SSH instead. Replace
<node>.<cluster_name>.<base_domain>
with appropriate values:$ ssh core@<node>.<cluster_name>.<base_domain> journalctl -b -f -u crio.service
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. Before attempting to collect diagnostic data over SSH, review whether the data collected by running
oc adm must gather
and otheroc
commands is sufficient instead. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
.
7.3.4. Cleaning CRI-O storage
You can manually clear the CRI-O ephemeral storage if you experience the following issues:
A node cannot run on any pods and this error appears:
Failed to create pod sandbox: rpc error: code = Unknown desc = failed to mount container XXX: error recreating the missing symlinks: error reading name of symlink for XXX: open /var/lib/containers/storage/overlay/XXX/link: no such file or directory
You cannot create a new container on a working node and the “can’t stat lower layer” error appears:
can't stat lower layer ... because it does not exist. Going through storage to recreate the missing symlinks.
-
Your node is in the
NotReady
state after a cluster upgrade or if you attempt to reboot it. -
The container runtime implementation (
crio
) is not working properly. -
You are unable to start a debug shell on the node using
oc debug node/<nodename>
because the container runtime instance (crio
) is not working.
Follow this process to completely wipe the CRI-O storage and resolve the errors.
Prerequisites:
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
Use
cordon
on the node. This is to avoid any workload getting scheduled if the node gets into theReady
status. You will know that scheduling is disabled whenSchedulingDisabled
is in your Status section:$ oc adm cordon <nodename>
Drain the node as the cluster-admin user:
$ oc adm drain <nodename> --ignore-daemonsets --delete-emptydir-data
NoteThe
terminationGracePeriodSeconds
attribute of a pod or pod template controls the graceful termination period. This attribute defaults at 30 seconds, but can be customized per application as necessary. If set to more than 90 seconds, the pod might be marked asSIGKILLed
and fail to terminate successfully.When the node returns, connect back to the node via SSH or Console. Then connect to the root user:
$ ssh core@node1.example.com $ sudo -i
Manually stop the kubelet:
# systemctl stop kubelet
Stop the containers and pods:
Use the following command to stop the pods that are not in the
HostNetwork
. They must be removed first because their removal relies on the networking plugin pods, which are in theHostNetwork
... for pod in $(crictl pods -q); do if [[ "$(crictl inspectp $pod | jq -r .status.linux.namespaces.options.network)" != "NODE" ]]; then crictl rmp -f $pod; fi; done
Stop all other pods:
# crictl rmp -fa
Manually stop the crio services:
# systemctl stop crio
After you run those commands, you can completely wipe the ephemeral storage:
# crio wipe -f
Start the crio and kubelet service:
# systemctl start crio # systemctl start kubelet
You will know if the clean up worked if the crio and kubelet services are started, and the node is in the
Ready
status:$ oc get nodes
Example output
NAME STATUS ROLES AGE VERSION ci-ln-tkbxyft-f76d1-nvwhr-master-1 Ready, SchedulingDisabled master 133m v1.22.0-rc.0+75ee307
Mark the node schedulable. You will know that the scheduling is enabled when
SchedulingDisabled
is no longer in status:$ oc adm uncordon <nodename>
Example output
NAME STATUS ROLES AGE VERSION ci-ln-tkbxyft-f76d1-nvwhr-master-1 Ready master 133m v1.22.0-rc.0+75ee307
7.4. Troubleshooting operating system issues
OpenShift Container Platform runs on RHCOS. You can follow these procedures to troubleshoot problems related to the operating system.
7.4.1. Investigating kernel crashes
The kdump
service, included in kexec-tools
, provides a crash-dumping mechanism. You can use this service to save the contents of the system’s memory for later analysis.
The kdump
service is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see https://access.redhat.com/support/offerings/techpreview/.
7.4.1.1. Enabling kdump
RHCOS ships with kexec-tools
, but manual configuration is required to enable kdump
.
Procedure
Perform the following steps to enable kdump
on RHCOS:
To reserve memory for the crash kernel during the first kernel booting, provide kernel arguments by entering the following command:
# rpm-ostree kargs --append='crashkernel=256M'
Optional: To write the crash dump over the network or to some other location, rather than to the default local
/var/crash
location, edit the/etc/kdump.conf
configuration file.NoteNetwork dumps are required when using LUKS.
kdump
does not support local crash dumps on LUKS-encrypted devices.For details on configuring the
kdump
service, see the comments in/etc/sysconfig/kdump
,/etc/kdump.conf
, and thekdump.conf
manual page. Also refer to the RHELkdump
documentation for further information on configuring the dump target.Enable the
kdump
systemd service:# systemctl enable kdump.service
Reboot your system:
# systemctl reboot
-
Ensure that
kdump
has loaded a crash kernel by checking that thekdump.service
has started and exited successfully and thatcat /sys/kernel/kexec_crash_loaded
prints1
.
7.4.1.2. Enabling kdump on day-1
The kdump
service is intended to be enabled per node to debug kernel problems. Because there are costs to having kdump
enabled, and these costs accumulate with each additional kdump
-enabled node, it is recommended that kdump
only be enabled on each node as needed. Potential costs of enabling kdump
on each node include:
- Less available RAM due to memory being reserved for the crash kernel.
- Node unavailability while the kernel is dumping the core.
- Additional storage space being used to store the crash dumps.
-
Not being production-ready because the
kdump
service is in Technology Preview.
If you are aware of the downsides and trade-offs of having the kdump
service enabled, it is possible to enable kdump
in a cluster-wide fashion. Although machine-specific machine configs are not yet supported, you can perform the previous steps through a systemd
unit in a MachineConfig
object on day-1 and have kdump enabled on all nodes in the cluster. You can create a MachineConfig
object and inject that object into the set of manifest files used by Ignition during cluster setup. See "Customizing nodes" in the Installing → Installation configuration section for more information and examples on how to use Ignition configs.
Procedure
Create a MachineConfig
object for cluster-wide configuration:
Create a Butane config file,
99-worker-kdump.bu
, that configures and enables kdump:variant: openshift version: 4.8.0 metadata: name: 99-worker-kdump 1 labels: machineconfiguration.openshift.io/role: worker 2 openshift: kernel_arguments: 3 - crashkernel=256M storage: files: - path: /etc/kdump.conf 4 mode: 0644 overwrite: true contents: inline: | path /var/crash core_collector makedumpfile -l --message-level 7 -d 31 - path: /etc/sysconfig/kdump 5 mode: 0644 overwrite: true contents: inline: | KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet log_buf_len swiotlb" KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug transparent_hugepage=never nokaslr novmcoredd hest_disable" KEXEC_ARGS="-s" KDUMP_IMG="vmlinuz" systemd: units: - name: kdump.service enabled: true
- 1 2
- Replace
worker
withmaster
in both locations when creating aMachineConfig
object for control plane nodes. - 3
- Provide kernel arguments to reserve memory for the crash kernel. You can add other kernel arguments if necessary.
- 4
- If you want to change the contents of
/etc/kdump.conf
from the default, include this section and modify theinline
subsection accordingly. - 5
- If you want to change the contents of
/etc/sysconfig/kdump
from the default, include this section and modify theinline
subsection accordingly.
Use Butane to generate a machine config YAML file,
99-worker-kdump.yaml
, containing the configuration to be delivered to the nodes:$ butane 99-worker-kdump.bu -o 99-worker-kdump.yaml
Put the YAML file into manifests during cluster setup. You can also create this
MachineConfig
object after cluster setup with the YAML file:$ oc create -f ./99-worker-kdump.yaml
7.4.1.3. Testing the kdump configuration
See the Testing the kdump configuration section in the RHEL documentation for kdump.
7.4.1.4. Analyzing a core dump
See the Analyzing a core dump section in the RHEL documentation for kdump.
It is recommended to perform vmcore analysis on a separate RHEL system.
Additional resources
- Setting up kdump in RHEL
- Linux kernel documentation for kdump
-
kdump.conf(5) — a manual page for the
/etc/kdump.conf
configuration file containing the full documentation of available options -
kexec(8) — a manual page for the
kexec
package - Red Hat Knowledgebase article regarding kexec and kdump
7.4.2. Debugging Ignition failures
If a machine cannot be provisioned, Ignition fails and RHCOS will boot into the emergency shell. Use the following procedure to get debugging information.
Procedure
Run the following command to show which service units failed:
$ systemctl --failed
Optional: Run the following command on an individual service unit to find out more information:
$ journalctl -u <unit>.service
7.5. Troubleshooting network issues
7.5.1. How the network interface is selected
For installations on bare metal or with virtual machines that have more than one network interface controller (NIC), the NIC that OpenShift Container Platform uses for communication with the Kubernetes API server is determined by the nodeip-configuration.service
service unit that is run by systemd when the node boots. The service iterates through the network interfaces on the node and the first network interface that is configured with a subnet than can host the IP address for the API server is selected for OpenShift Container Platform communication.
After the nodeip-configuration.service
service determines the correct NIC, the service creates the /etc/systemd/system/kubelet.service.d/20-nodenet.conf
file. The 20-nodenet.conf
file sets the KUBELET_NODE_IP
environment variable to the IP address that the service selected.
When the kubelet service starts, it reads the value of the environment variable from the 20-nodenet.conf
file and sets the IP address as the value to the --node-ip
kubelet command-line argument. As a result, the kubelet service uses the selected IP address as the node IP address.
If hardware or networking is reconfigured after installation, it is possible that the nodeip-configuration.service
service can select a different NIC after a reboot. In some cases, you might be able to detect that a different NIC is selected by reviewing the INTERNAL-IP
column in the output from the oc get nodes -o wide
command.
If network communication is disrupted or misconfigured because a different NIC is selected, one strategy for overriding the selection process is to set the correct IP address explicitly. The following list identifies the high-level steps and considerations:
-
Create a shell script that determines the IP address to use for OpenShift Container Platform communication. Have the script create a custom unit file such as
/etc/systemd/system/kubelet.service.d/98-nodenet-override.conf
. Use the custom unit file,98-nodenet-override.conf
, to set theKUBELET_NODE_IP
environment variable to the IP address. -
Do not overwrite the
/etc/systemd/system/kubelet.service.d/20-nodenet.conf
file. Specify a file name with a numerically higher value such as98-nodenet-override.conf
in the same directory path. The goal is to have the custom unit file run after20-nodenet.conf
and override the value of the environment variable. -
Create a machine config object with the shell script as a base64-encoded string and use the Machine Config Operator to deploy the script to the nodes at a file system path such as
/usr/local/bin/override-node-ip.sh
. -
Ensure that
systemctl daemon-reload
runs after the shell script runs. The simplest method is to specifyExecStart=systemctl daemon-reload
in the machine config, as shown in the following sample.
Sample machine config to override the network interface for kubelet
apiVersion: machineconfiguration.openshift.io/v1 kind: MachineConfig metadata: labels: machineconfiguration.openshift.io/role: worker name: 98-nodenet-override spec: config: ignition: version: 3.2.0 storage: files: - contents: source: data:text/plain;charset=utf-8;base64,<encoded_script> mode: 0755 overwrite: true path: /usr/local/bin/override-node-ip.sh systemd: units: - contents: | [Unit] Description=Override node IP detection Wants=network-online.target Before=kubelet.service After=network-online.target [Service] Type=oneshot ExecStart=/usr/local/bin/override-node-ip.sh ExecStart=systemctl daemon-reload [Install] WantedBy=multi-user.target enabled: true name: nodenet-override.service
7.5.2. Troubleshooting Open vSwitch issues
To troubleshoot some Open vSwitch (OVS) issues, you might need to configure the log level to include more information.
If you modify the log level on a node temporarily, be aware that you can receive log messages from the machine config daemon on the node like the following example:
E0514 12:47:17.998892 2281 daemon.go:1350] content mismatch for file /etc/systemd/system/ovs-vswitchd.service: [Unit]
To avoid the log messages related to the mismatch, revert the log level change after you complete your troubleshooting.
7.5.2.1. Configuring the Open vSwitch log level temporarily
For short-term troubleshooting, you can configure the Open vSwitch (OVS) log level temporarily. The following procedure does not require rebooting the node. In addition, the configuration change does not persist whenever you reboot the node.
After you perform this procedure to change the log level, you can receive log messages from the machine config daemon that indicate a content mismatch for the ovs-vswitchd.service
. To avoid the log messages, repeat this procedure and set the log level to the original value.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
Start a debug pod for a node:
$ oc debug node/<node_name>
Set
/host
as the root directory within the debug shell. The debug pod mounts the root file system from the host in/host
within the pod. By changing the root directory to/host
, you can run binaries from the host file system:# chroot /host
View the current syslog level for OVS modules:
# ovs-appctl vlog/list
The following example output shows the log level for syslog set to
info
.Example output
console syslog file ------- ------ ------ backtrace OFF INFO INFO bfd OFF INFO INFO bond OFF INFO INFO bridge OFF INFO INFO bundle OFF INFO INFO bundles OFF INFO INFO cfm OFF INFO INFO collectors OFF INFO INFO command_line OFF INFO INFO connmgr OFF INFO INFO conntrack OFF INFO INFO conntrack_tp OFF INFO INFO coverage OFF INFO INFO ct_dpif OFF INFO INFO daemon OFF INFO INFO daemon_unix OFF INFO INFO dns_resolve OFF INFO INFO dpdk OFF INFO INFO ...
Specify the log level in the
/etc/systemd/system/ovs-vswitchd.service.d/10-ovs-vswitchd-restart.conf
file:Restart=always ExecStartPre=-/bin/sh -c '/usr/bin/chown -R :$${OVS_USER_ID##*:} /var/lib/openvswitch' ExecStartPre=-/bin/sh -c '/usr/bin/chown -R :$${OVS_USER_ID##*:} /etc/openvswitch' ExecStartPre=-/bin/sh -c '/usr/bin/chown -R :$${OVS_USER_ID##*:} /run/openvswitch' ExecStartPost=-/usr/bin/ovs-appctl vlog/set syslog:dbg ExecReload=-/usr/bin/ovs-appctl vlog/set syslog:dbg
In the preceding example, the log level is set to
dbg
. Change the last two lines by settingsyslog:<log_level>
tooff
,emer
,err
,warn
,info
, ordbg
. Theoff
log level filters out all log messages.Restart the service:
# systemctl daemon-reload
# systemctl restart ovs-vswitchd
7.5.2.2. Configuring the Open vSwitch log level permanently
For long-term changes to the Open vSwitch (OVS) log level, you can change the log level permanently.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
Create a file, such as
99-change-ovs-loglevel.yaml
, with aMachineConfig
object like the following example:apiVersion: machineconfiguration.openshift.io/v1 kind: MachineConfig metadata: labels: machineconfiguration.openshift.io/role: master 1 name: 99-change-ovs-loglevel spec: config: ignition: version: 3.2.0 systemd: units: - dropins: - contents: | [Service] ExecStartPost=-/usr/bin/ovs-appctl vlog/set syslog:dbg 2 ExecReload=-/usr/bin/ovs-appctl vlog/set syslog:dbg name: 20-ovs-vswitchd-restart.conf name: ovs-vswitchd.service
Apply the machine config:
$ oc apply -f 99-change-ovs-loglevel.yaml
Additional resources
7.5.2.3. Displaying Open vSwitch logs
Use the following procedure to display Open vSwitch (OVS) logs.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
Run one of the following commands:
Display the logs by using the
oc
command from outside the cluster:$ oc adm node-logs <node_name> -u ovs-vswitchd
Display the logs after logging on to a node in the cluster:
# journalctl -b -f -u ovs-vswitchd.service
One way to log on to a node is by using the
oc debug node/<node_name>
command.
7.6. Troubleshooting Operator issues
Operators are a method of packaging, deploying, and managing an OpenShift Container Platform application. They act like an extension of the software vendor’s engineering team, watching over an OpenShift Container Platform environment and using its current state to make decisions in real time. Operators are designed to handle upgrades seamlessly, react to failures automatically, and not take shortcuts, such as skipping a software backup process to save time.
OpenShift Container Platform 4.8 includes a default set of Operators that are required for proper functioning of the cluster. These default Operators are managed by the Cluster Version Operator (CVO).
As a cluster administrator, you can install application Operators from the OperatorHub using the OpenShift Container Platform web console or the CLI. You can then subscribe the Operator to one or more namespaces to make it available for developers on your cluster. Application Operators are managed by Operator Lifecycle Manager (OLM).
If you experience Operator issues, verify Operator subscription status. Check Operator pod health across the cluster and gather Operator logs for diagnosis.
7.6.1. Operator subscription condition types
Subscriptions can report the following condition types:
Condition | Description |
---|---|
| Some or all of the catalog sources to be used in resolution are unhealthy. |
| An install plan for a subscription is missing. |
| An install plan for a subscription is pending installation. |
| An install plan for a subscription has failed. |
Default OpenShift Container Platform cluster Operators are managed by the Cluster Version Operator (CVO) and they do not have a Subscription
object. Application Operators are managed by Operator Lifecycle Manager (OLM) and they have a Subscription
object.
7.6.2. Viewing Operator subscription status by using the CLI
You can view Operator subscription status by using the CLI.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
List Operator subscriptions:
$ oc get subs -n <operator_namespace>
Use the
oc describe
command to inspect aSubscription
resource:$ oc describe sub <subscription_name> -n <operator_namespace>
In the command output, find the
Conditions
section for the status of Operator subscription condition types. In the following example, theCatalogSourcesUnhealthy
condition type has a status offalse
because all available catalog sources are healthy:Example output
Conditions: Last Transition Time: 2019-07-29T13:42:57Z Message: all available catalogsources are healthy Reason: AllCatalogSourcesHealthy Status: False Type: CatalogSourcesUnhealthy
Default OpenShift Container Platform cluster Operators are managed by the Cluster Version Operator (CVO) and they do not have a Subscription
object. Application Operators are managed by Operator Lifecycle Manager (OLM) and they have a Subscription
object.
7.6.3. Viewing Operator catalog source status by using the CLI
You can view the status of an Operator catalog source by using the CLI.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
List the catalog sources in a namespace. For example, you can check the
openshift-marketplace
namespace, which is used for cluster-wide catalog sources:$ oc get catalogsources -n openshift-marketplace
Example output
NAME DISPLAY TYPE PUBLISHER AGE certified-operators Certified Operators grpc Red Hat 55m community-operators Community Operators grpc Red Hat 55m example-catalog Example Catalog grpc Example Org 2m25s redhat-marketplace Red Hat Marketplace grpc Red Hat 55m redhat-operators Red Hat Operators grpc Red Hat 55m
Use the
oc describe
command to get more details and status about a catalog source:$ oc describe catalogsource example-catalog -n openshift-marketplace
Example output
Name: example-catalog Namespace: openshift-marketplace ... Status: Connection State: Address: example-catalog.openshift-marketplace.svc:50051 Last Connect: 2021-09-09T17:07:35Z Last Observed State: TRANSIENT_FAILURE Registry Service: Created At: 2021-09-09T17:05:45Z Port: 50051 Protocol: grpc Service Name: example-catalog Service Namespace: openshift-marketplace
In the preceding example output, the last observed state is
TRANSIENT_FAILURE
. This state indicates that there is a problem establishing a connection for the catalog source.List the pods in the namespace where your catalog source was created:
$ oc get pods -n openshift-marketplace
Example output
NAME READY STATUS RESTARTS AGE certified-operators-cv9nn 1/1 Running 0 36m community-operators-6v8lp 1/1 Running 0 36m marketplace-operator-86bfc75f9b-jkgbc 1/1 Running 0 42m example-catalog-bwt8z 0/1 ImagePullBackOff 0 3m55s redhat-marketplace-57p8c 1/1 Running 0 36m redhat-operators-smxx8 1/1 Running 0 36m
When a catalog source is created in a namespace, a pod for the catalog source is created in that namespace. In the preceding example output, the status for the
example-catalog-bwt8z
pod isImagePullBackOff
. This status indicates that there is an issue pulling the catalog source’s index image.Use the
oc describe
command to inspect a pod for more detailed information:$ oc describe pod example-catalog-bwt8z -n openshift-marketplace
Example output
Name: example-catalog-bwt8z Namespace: openshift-marketplace Priority: 0 Node: ci-ln-jyryyg2-f76d1-ggdbq-worker-b-vsxjd/10.0.128.2 ... Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Scheduled 48s default-scheduler Successfully assigned openshift-marketplace/example-catalog-bwt8z to ci-ln-jyryyf2-f76d1-fgdbq-worker-b-vsxjd Normal AddedInterface 47s multus Add eth0 [10.131.0.40/23] from openshift-sdn Normal BackOff 20s (x2 over 46s) kubelet Back-off pulling image "quay.io/example-org/example-catalog:v1" Warning Failed 20s (x2 over 46s) kubelet Error: ImagePullBackOff Normal Pulling 8s (x3 over 47s) kubelet Pulling image "quay.io/example-org/example-catalog:v1" Warning Failed 8s (x3 over 47s) kubelet Failed to pull image "quay.io/example-org/example-catalog:v1": rpc error: code = Unknown desc = reading manifest v1 in quay.io/example-org/example-catalog: unauthorized: access to the requested resource is not authorized Warning Failed 8s (x3 over 47s) kubelet Error: ErrImagePull
In the preceding example output, the error messages indicate that the catalog source’s index image is failing to pull successfully because of an authorization issue. For example, the index image might be stored in a registry that requires login credentials.
Additional resources
7.6.4. Querying Operator pod status
You can list Operator pods within a cluster and their status. You can also collect a detailed Operator pod summary.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
).
Procedure
List Operators running in the cluster. The output includes Operator version, availability, and up-time information:
$ oc get clusteroperators
List Operator pods running in the Operator’s namespace, plus pod status, restarts, and age:
$ oc get pod -n <operator_namespace>
Output a detailed Operator pod summary:
$ oc describe pod <operator_pod_name> -n <operator_namespace>
If an Operator issue is node-specific, query Operator container status on that node.
Start a debug pod for the node:
$ oc debug node/my-node
Set
/host
as the root directory within the debug shell. The debug pod mounts the host’s root file system in/host
within the pod. By changing the root directory to/host
, you can run binaries contained in the host’s executable paths:# chroot /host
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,
oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
instead.List details about the node’s containers, including state and associated pod IDs:
# crictl ps
List information about a specific Operator container on the node. The following example lists information about the
network-operator
container:# crictl ps --name network-operator
- Exit from the debug shell.
7.6.5. Gathering Operator logs
If you experience Operator issues, you can gather detailed diagnostic information from Operator pod logs.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
). - You have the fully qualified domain names of the control plane, or control plane machines (also known as the master machines).
Procedure
List the Operator pods that are running in the Operator’s namespace, plus the pod status, restarts, and age:
$ oc get pods -n <operator_namespace>
Review logs for an Operator pod:
$ oc logs pod/<pod_name> -n <operator_namespace>
If an Operator pod has multiple containers, the preceding command will produce an error that includes the name of each container. Query logs from an individual container:
$ oc logs pod/<operator_pod_name> -c <container_name> -n <operator_namespace>
If the API is not functional, review Operator pod and container logs on each control plane node by using SSH instead. Replace
<master-node>.<cluster_name>.<base_domain>
with appropriate values.List pods on each control plane node:
$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl pods
For any Operator pods not showing a
Ready
status, inspect the pod’s status in detail. Replace<operator_pod_id>
with the Operator pod’s ID listed in the output of the preceding command:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl inspectp <operator_pod_id>
List containers related to an Operator pod:
$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl ps --pod=<operator_pod_id>
For any Operator container not showing a
Ready
status, inspect the container’s status in detail. Replace<container_id>
with a container ID listed in the output of the preceding command:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl inspect <container_id>
Review the logs for any Operator containers not showing a
Ready
status. Replace<container_id>
with a container ID listed in the output of the preceding command:$ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl logs -f <container_id>
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. Before attempting to collect diagnostic data over SSH, review whether the data collected by running
oc adm must gather
and otheroc
commands is sufficient instead. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
.
7.6.6. Disabling the Machine Config Operator from automatically rebooting
When configuration changes are made by the Machine Config Operator (MCO), Red Hat Enterprise Linux CoreOS (RHCOS) must reboot for the changes to take effect. Whether the configuration change is automatic or manual, an RHCOS node reboots automatically unless it is paused.
The following modifications do not trigger a node reboot:
When the MCO detects any of the following changes, it applies the update without draining or rebooting the node:
-
Changes to the SSH key in the
spec.config.passwd.users.sshAuthorizedKeys
parameter of a machine config. -
Changes to the global pull secret or pull secret in the
openshift-config
namespace. -
Automatic rotation of the
/etc/kubernetes/kubelet-ca.crt
certificate authority (CA) by the Kubernetes API Server Operator.
-
Changes to the SSH key in the
When the MCO detects changes to the
/etc/containers/registries.conf
file, such as adding or editing anImageDigestMirrorSet
orImageTagMirrorSet
object, it drains the corresponding nodes, applies the changes, and uncordons the nodes.The node drain does not happen for the following changes:-
The addition of a registry with the
pull-from-mirror = "digest-only"
parameter set for each mirror. -
The addition of a mirror with the
pull-from-mirror = "digest-only"
parameter set in a registry. -
The addition of items to the
unqualified-search-registries
list.
-
The addition of a registry with the
To avoid unwanted disruptions, you can modify the machine config pool (MCP) to prevent automatic rebooting after the Operator makes changes to the machine config.
Pausing an MCP prevents the MCO from applying any configuration changes on the associated nodes. Pausing an MCP also prevents any automatically-rotated certificates from being pushed to the associated nodes, including the automatic rotation of the kube-apiserver-to-kubelet-signer
CA certificate. If the MCP is paused when the kube-apiserver-to-kubelet-signer
CA certificate expires, and the MCO attempts to renew the certificate automatically, the new certificate is created but not applied across the nodes in the paused MCP. This causes failure in multiple oc
commands, including but not limited to oc debug
, oc logs
, oc exec
, and oc attach
. Pausing an MCP should be done with careful consideration about the kube-apiserver-to-kubelet-signer
CA certificate expiration and for short periods of time only.
New CA certificates are generated at 292 days from the installation date and removed at 365 days from that date. To determine the next automatic CA certificate rotation, see the Understand CA cert auto renewal in Red Hat OpenShift 4.
7.6.6.1. Disabling the Machine Config Operator from automatically rebooting by using the console
To avoid unwanted disruptions from changes made by the Machine Config Operator (MCO), you can use the OpenShift Container Platform web console to modify the machine config pool (MCP) to prevent the MCO from making any changes to nodes in that pool. This prevents any reboots that would normally be part of the MCO update process.
Pausing an MCP prevents the MCO from applying any configuration changes on the associated nodes. Pausing an MCP also prevents any automatically-rotated certificates from being pushed to the associated nodes, including the automatic rotation of the kube-apiserver-to-kubelet-signer
CA certificate. If the MCP is paused when the kube-apiserver-to-kubelet-signer
CA certificate expires, and the MCO attempts to renew the certificate automatically, the new certificate is created but not applied across the nodes in the paused MCP. This causes failure in multiple oc
commands, including but not limited to oc debug
, oc logs
, oc exec
, and oc attach
. Pausing an MCP should be done with careful consideration about the kube-apiserver-to-kubelet-signer
CA certificate expiration and for short periods of time only.
New CA certificates are generated at 292 days from the installation date and removed at 365 days from that date. To determine the next automatic CA certificate rotation, see the Understand CA cert auto renewal in Red Hat OpenShift 4.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role.
Procedure
To pause or unpause automatic MCO update rebooting:
Pause the autoreboot process:
-
Log in to the OpenShift Container Platform web console as a user with the
cluster-admin
role. - Click Compute → MachineConfigPools.
- On the MachineConfigPools page, click either master or worker, depending upon which nodes you want to pause rebooting for.
- On the master or worker page, click YAML.
In the YAML, update the
spec.paused
field totrue
.Sample MachineConfigPool object
apiVersion: machineconfiguration.openshift.io/v1 kind: MachineConfigPool ... spec: ... paused: true 1
- 1
- Update the
spec.paused
field totrue
to pause rebooting.
To verify that the MCP is paused, return to the MachineConfigPools page.
On the MachineConfigPools page, the Paused column reports True for the MCP you modified.
If the MCP has pending changes while paused, the Updated column is False and Updating is False. When Updated is True and Updating is False, there are no pending changes.
ImportantIf there are pending changes (where both the Updated and Updating columns are False), it is recommended to schedule a maintenance window for a reboot as early as possible. Use the following steps for unpausing the autoreboot process to apply the changes that were queued since the last reboot.
-
Log in to the OpenShift Container Platform web console as a user with the
Unpause the autoreboot process:
-
Log in to the OpenShift Container Platform web console as a user with the
cluster-admin
role. - Click Compute → MachineConfigPools.
- On the MachineConfigPools page, click either master or worker, depending upon which nodes you want to pause rebooting for.
- On the master or worker page, click YAML.
In the YAML, update the
spec.paused
field tofalse
.Sample MachineConfigPool object
apiVersion: machineconfiguration.openshift.io/v1 kind: MachineConfigPool ... spec: ... paused: false 1
- 1
- Update the
spec.paused
field tofalse
to allow rebooting.
NoteBy unpausing an MCP, the MCO applies all paused changes reboots Red Hat Enterprise Linux CoreOS (RHCOS) as needed.
To verify that the MCP is paused, return to the MachineConfigPools page.
On the MachineConfigPools page, the Paused column reports False for the MCP you modified.
If the MCP is applying any pending changes, the Updated column is False and the Updating column is True. When Updated is True and Updating is False, there are no further changes being made.
-
Log in to the OpenShift Container Platform web console as a user with the
7.6.6.2. Disabling the Machine Config Operator from automatically rebooting by using the CLI
To avoid unwanted disruptions from changes made by the Machine Config Operator (MCO), you can modify the machine config pool (MCP) using the OpenShift CLI (oc) to prevent the MCO from making any changes to nodes in that pool. This prevents any reboots that would normally be part of the MCO update process.
Pausing an MCP prevents the MCO from applying any configuration changes on the associated nodes. Pausing an MCP also prevents any automatically-rotated certificates from being pushed to the associated nodes, including the automatic rotation of the kube-apiserver-to-kubelet-signer
CA certificate. If the MCP is paused when the kube-apiserver-to-kubelet-signer
CA certificate expires, and the MCO attempts to renew the certificate automatically, the new certificate is created but not applied across the nodes in the paused MCP. This causes failure in multiple oc
commands, including but not limited to oc debug
, oc logs
, oc exec
, and oc attach
. Pausing an MCP should be done with careful consideration about the kube-apiserver-to-kubelet-signer
CA certificate expiration and for short periods of time only.
New CA certificates are generated at 292 days from the installation date and removed at 365 days from that date. To determine the next automatic CA certificate rotation, see the Understand CA cert auto renewal in Red Hat OpenShift 4.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
To pause or unpause automatic MCO update rebooting:
Pause the autoreboot process:
Update the
MachineConfigPool
custom resource to set thespec.paused
field totrue
.Control plane (master) nodes
$ oc patch --type=merge --patch='{"spec":{"paused":true}}' machineconfigpool/master
Worker nodes
$ oc patch --type=merge --patch='{"spec":{"paused":true}}' machineconfigpool/worker
Verify that the MCP is paused:
Control plane (master) nodes
$ oc get machineconfigpool/master --template='{{.spec.paused}}'
Worker nodes
$ oc get machineconfigpool/worker --template='{{.spec.paused}}'
Example output
true
The
spec.paused
field istrue
and the MCP is paused.Determine if the MCP has pending changes:
# oc get machineconfigpool
Example output
NAME CONFIG UPDATED UPDATING master rendered-master-33cf0a1254318755d7b48002c597bf91 True False worker rendered-worker-e405a5bdb0db1295acea08bcca33fa60 False False
If the UPDATED column is False and UPDATING is False, there are pending changes. When UPDATED is True and UPDATING is False, there are no pending changes. In the previous example, the worker node has pending changes. The control plane node (also known as the master node) does not have any pending changes.
ImportantIf there are pending changes (where both the Updated and Updating columns are False), it is recommended to schedule a maintenance window for a reboot as early as possible. Use the following steps for unpausing the autoreboot process to apply the changes that were queued since the last reboot.
Unpause the autoreboot process:
Update the
MachineConfigPool
custom resource to set thespec.paused
field tofalse
.Control plane (master) nodes
$ oc patch --type=merge --patch='{"spec":{"paused":false}}' machineconfigpool/master
Worker nodes
$ oc patch --type=merge --patch='{"spec":{"paused":false}}' machineconfigpool/worker
NoteBy unpausing an MCP, the MCO applies all paused changes and reboots Red Hat Enterprise Linux CoreOS (RHCOS) as needed.
Verify that the MCP is unpaused:
Control plane (master) nodes
$ oc get machineconfigpool/master --template='{{.spec.paused}}'
Worker nodes
$ oc get machineconfigpool/worker --template='{{.spec.paused}}'
Example output
false
The
spec.paused
field isfalse
and the MCP is unpaused.Determine if the MCP has pending changes:
$ oc get machineconfigpool
Example output
NAME CONFIG UPDATED UPDATING master rendered-master-546383f80705bd5aeaba93 True False worker rendered-worker-b4c51bb33ccaae6fc4a6a5 False True
If the MCP is applying any pending changes, the UPDATED column is False and the UPDATING column is True. When UPDATED is True and UPDATING is False, there are no further changes being made. In the previous example, the MCO is updating the worker node.
7.6.7. Refreshing failing subscriptions
In Operator Lifecycle Manager (OLM), if you subscribe to an Operator that references images that are not accessible on your network, you can find jobs in the openshift-marketplace
namespace that are failing with the following errors:
Example output
ImagePullBackOff for Back-off pulling image "example.com/openshift4/ose-elasticsearch-operator-bundle@sha256:6d2587129c846ec28d384540322b40b05833e7e00b25cca584e004af9a1d292e"
Example output
rpc error: code = Unknown desc = error pinging docker registry example.com: Get "https://example.com/v2/": dial tcp: lookup example.com on 10.0.0.1:53: no such host
As a result, the subscription is stuck in this failing state and the Operator is unable to install or upgrade.
You can refresh a failing subscription by deleting the subscription, cluster service version (CSV), and other related objects. After recreating the subscription, OLM then reinstalls the correct version of the Operator.
Prerequisites
- You have a failing subscription that is unable to pull an inaccessible bundle image.
- You have confirmed that the correct bundle image is accessible.
Procedure
Get the names of the
Subscription
andClusterServiceVersion
objects from the namespace where the Operator is installed:$ oc get sub,csv -n <namespace>
Example output
NAME PACKAGE SOURCE CHANNEL subscription.operators.coreos.com/elasticsearch-operator elasticsearch-operator redhat-operators 5.0 NAME DISPLAY VERSION REPLACES PHASE clusterserviceversion.operators.coreos.com/elasticsearch-operator.5.0.0-65 OpenShift Elasticsearch Operator 5.0.0-65 Succeeded
Delete the subscription:
$ oc delete subscription <subscription_name> -n <namespace>
Delete the cluster service version:
$ oc delete csv <csv_name> -n <namespace>
Get the names of any failing jobs and related config maps in the
openshift-marketplace
namespace:$ oc get job,configmap -n openshift-marketplace
Example output
NAME COMPLETIONS DURATION AGE job.batch/1de9443b6324e629ddf31fed0a853a121275806170e34c926d69e53a7fcbccb 1/1 26s 9m30s NAME DATA AGE configmap/1de9443b6324e629ddf31fed0a853a121275806170e34c926d69e53a7fcbccb 3 9m30s
Delete the job:
$ oc delete job <job_name> -n openshift-marketplace
This ensures pods that try to pull the inaccessible image are not recreated.
Delete the config map:
$ oc delete configmap <configmap_name> -n openshift-marketplace
- Reinstall the Operator using OperatorHub in the web console.
Verification
Check that the Operator has been reinstalled successfully:
$ oc get sub,csv,installplan -n <namespace>
7.7. Investigating pod issues
OpenShift Container Platform leverages the Kubernetes concept of a pod, which is one or more containers deployed together on one host. A pod is the smallest compute unit that can be defined, deployed, and managed on OpenShift Container Platform 4.8.
After a pod is defined, it is assigned to run on a node until its containers exit, or until it is removed. Depending on policy and exit code, Pods are either removed after exiting or retained so that their logs can be accessed.
The first thing to check when pod issues arise is the pod’s status. If an explicit pod failure has occurred, observe the pod’s error state to identify specific image, container, or pod network issues. Focus diagnostic data collection according to the error state. Review pod event messages, as well as pod and container log information. Diagnose issues dynamically by accessing running Pods on the command line, or start a debug pod with root access based on a problematic pod’s deployment configuration.
7.7.1. Understanding pod error states
Pod failures return explicit error states that can be observed in the status
field in the output of oc get pods
. Pod error states cover image, container, and container network related failures.
The following table provides a list of pod error states along with their descriptions.
Pod error state | Description |
---|---|
| Generic image retrieval error. |
| Image retrieval failed and is backed off. |
| The specified image name was invalid. |
| Image inspection did not succeed. |
|
|
| When attempting to retrieve an image from a registry, an HTTP error was encountered. |
| The specified container is either not present or not managed by the kubelet, within the declared pod. |
| Container initialization failed. |
| None of the pod’s containers started successfully. |
| None of the pod’s containers were killed successfully. |
| A container has terminated. The kubelet will not attempt to restart it. |
| A container or image attempted to run with root privileges. |
| Pod sandbox creation did not succeed. |
| Pod sandbox configuration was not obtained. |
| A pod sandbox did not stop successfully. |
| Network initialization failed. |
| Network termination failed. |
7.7.2. Reviewing pod status
You can query pod status and error states. You can also query a pod’s associated deployment configuration and review base image availability.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
). -
skopeo
is installed.
Procedure
Switch into a project:
$ oc project <project_name>
List pods running within the namespace, as well as pod status, error states, restarts, and age:
$ oc get pods
Determine whether the namespace is managed by a deployment configuration:
$ oc status
If the namespace is managed by a deployment configuration, the output includes the deployment configuration name and a base image reference.
Inspect the base image referenced in the preceding command’s output:
$ skopeo inspect docker://<image_reference>
If the base image reference is not correct, update the reference in the deployment configuration:
$ oc edit deployment/my-deployment
When deployment configuration changes on exit, the configuration will automatically redeploy. Watch pod status as the deployment progresses, to determine whether the issue has been resolved:
$ oc get pods -w
Review events within the namespace for diagnostic information relating to pod failures:
$ oc get events
7.7.3. Inspecting pod and container logs
You can inspect pod and container logs for warnings and error messages related to explicit pod failures. Depending on policy and exit code, pod and container logs remain available after pods have been terminated.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
).
Procedure
Query logs for a specific pod:
$ oc logs <pod_name>
Query logs for a specific container within a pod:
$ oc logs <pod_name> -c <container_name>
Logs retrieved using the preceding
oc logs
commands are composed of messages sent to stdout within pods or containers.Inspect logs contained in
/var/log/
within a pod.List log files and subdirectories contained in
/var/log
within a pod:$ oc exec <pod_name> ls -alh /var/log
Query a specific log file contained in
/var/log
within a pod:$ oc exec <pod_name> cat /var/log/<path_to_log>
List log files and subdirectories contained in
/var/log
within a specific container:$ oc exec <pod_name> -c <container_name> ls /var/log
Query a specific log file contained in
/var/log
within a specific container:$ oc exec <pod_name> -c <container_name> cat /var/log/<path_to_log>
7.7.4. Accessing running pods
You can review running pods dynamically by opening a shell inside a pod or by gaining network access through port forwarding.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
).
Procedure
Switch into the project that contains the pod you would like to access. This is necessary because the
oc rsh
command does not accept the-n
namespace option:$ oc project <namespace>
Start a remote shell into a pod:
$ oc rsh <pod_name> 1
- 1
- If a pod has multiple containers,
oc rsh
defaults to the first container unless-c <container_name>
is specified.
Start a remote shell into a specific container within a pod:
$ oc rsh -c <container_name> pod/<pod_name>
Create a port forwarding session to a port on a pod:
$ oc port-forward <pod_name> <host_port>:<pod_port> 1
- 1
- Enter
Ctrl+C
to cancel the port forwarding session.
7.7.5. Starting debug pods with root access
You can start a debug pod with root access, based on a problematic pod’s deployment or deployment configuration. Pod users typically run with non-root privileges, but running troubleshooting pods with temporary root privileges can be useful during issue investigation.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
).
Procedure
Start a debug pod with root access, based on a deployment.
Obtain a project’s deployment name:
$ oc get deployment -n <project_name>
Start a debug pod with root privileges, based on the deployment:
$ oc debug deployment/my-deployment --as-root -n <project_name>
Start a debug pod with root access, based on a deployment configuration.
Obtain a project’s deployment configuration name:
$ oc get deploymentconfigs -n <project_name>
Start a debug pod with root privileges, based on the deployment configuration:
$ oc debug deploymentconfig/my-deployment-configuration --as-root -n <project_name>
You can append -- <command>
to the preceding oc debug
commands to run individual commands within a debug pod, instead of running an interactive shell.
7.7.6. Copying files to and from pods and containers
You can copy files to and from a pod to test configuration changes or gather diagnostic information.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
).
Procedure
Copy a file to a pod:
$ oc cp <local_path> <pod_name>:/<path> -c <container_name> 1
- 1
- The first container in a pod is selected if the
-c
option is not specified.
Copy a file from a pod:
$ oc cp <pod_name>:/<path> -c <container_name><local_path> 1
- 1
- The first container in a pod is selected if the
-c
option is not specified.
NoteFor
oc cp
to function, thetar
binary must be available within the container.
7.8. Troubleshooting the Source-to-Image process
7.8.1. Strategies for Source-to-Image troubleshooting
Use Source-to-Image (S2I) to build reproducible, Docker-formatted container images. You can create ready-to-run images by injecting application source code into a container image and assembling a new image. The new image incorporates the base image (the builder) and built source.
To determine where in the S2I process a failure occurs, you can observe the state of the pods relating to each of the following S2I stages:
- During the build configuration stage, a build pod is used to create an application container image from a base image and application source code.
- During the deployment configuration stage, a deployment pod is used to deploy application pods from the application container image that was built in the build configuration stage. The deployment pod also deploys other resources such as services and routes. The deployment configuration begins after the build configuration succeeds.
-
After the deployment pod has started the application pods, application failures can occur within the running application pods. For instance, an application might not behave as expected even though the application pods are in a
Running
state. In this scenario, you can access running application pods to investigate application failures within a pod.
When troubleshooting S2I issues, follow this strategy:
- Monitor build, deployment, and application pod status
- Determine the stage of the S2I process where the problem occurred
- Review logs corresponding to the failed stage
7.8.2. Gathering Source-to-Image diagnostic data
The S2I tool runs a build pod and a deployment pod in sequence. The deployment pod is responsible for deploying the application pods based on the application container image created in the build stage. Watch build, deployment and application pod status to determine where in the S2I process a failure occurs. Then, focus diagnostic data collection accordingly.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. - Your API service is still functional.
-
You have installed the OpenShift CLI (
oc
).
Procedure
Watch the pod status throughout the S2I process to determine at which stage a failure occurs:
$ oc get pods -w 1
- 1
- Use
-w
to monitor pods for changes until you quit the command usingCtrl+C
.
Review a failed pod’s logs for errors.
If the build pod fails, review the build pod’s logs:
$ oc logs -f pod/<application_name>-<build_number>-build
NoteAlternatively, you can review the build configuration’s logs using
oc logs -f bc/<application_name>
. The build configuration’s logs include the logs from the build pod.If the deployment pod fails, review the deployment pod’s logs:
$ oc logs -f pod/<application_name>-<build_number>-deploy
NoteAlternatively, you can review the deployment configuration’s logs using
oc logs -f dc/<application_name>
. This outputs logs from the deployment pod until the deployment pod completes successfully. The command outputs logs from the application pods if you run it after the deployment pod has completed. After a deployment pod completes, its logs can still be accessed by runningoc logs -f pod/<application_name>-<build_number>-deploy
.If an application pod fails, or if an application is not behaving as expected within a running application pod, review the application pod’s logs:
$ oc logs -f pod/<application_name>-<build_number>-<random_string>
7.8.3. Gathering application diagnostic data to investigate application failures
Application failures can occur within running application pods. In these situations, you can retrieve diagnostic information with these strategies:
- Review events relating to the application pods.
- Review the logs from the application pods, including application-specific log files that are not collected by the OpenShift Logging framework.
- Test application functionality interactively and run diagnostic tools in an application container.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
List events relating to a specific application pod. The following example retrieves events for an application pod named
my-app-1-akdlg
:$ oc describe pod/my-app-1-akdlg
Review logs from an application pod:
$ oc logs -f pod/my-app-1-akdlg
Query specific logs within a running application pod. Logs that are sent to stdout are collected by the OpenShift Logging framework and are included in the output of the preceding command. The following query is only required for logs that are not sent to stdout.
If an application log can be accessed without root privileges within a pod, concatenate the log file as follows:
$ oc exec my-app-1-akdlg -- cat /var/log/my-application.log
If root access is required to view an application log, you can start a debug container with root privileges and then view the log file from within the container. Start the debug container from the project’s
DeploymentConfig
object. Pod users typically run with non-root privileges, but running troubleshooting pods with temporary root privileges can be useful during issue investigation:$ oc debug dc/my-deployment-configuration --as-root -- cat /var/log/my-application.log
NoteYou can access an interactive shell with root access within the debug pod if you run
oc debug dc/<deployment_configuration> --as-root
without appending-- <command>
.
Test application functionality interactively and run diagnostic tools, in an application container with an interactive shell.
Start an interactive shell on the application container:
$ oc exec -it my-app-1-akdlg /bin/bash
- Test application functionality interactively from within the shell. For example, you can run the container’s entry point command and observe the results. Then, test changes from the command line directly, before updating the source code and rebuilding the application container through the S2I process.
Run diagnostic binaries available within the container.
NoteRoot privileges are required to run some diagnostic binaries. In these situations you can start a debug pod with root access, based on a problematic pod’s
DeploymentConfig
object, by runningoc debug dc/<deployment_configuration> --as-root
. Then, you can run diagnostic binaries as root from within the debug pod.
If diagnostic binaries are not available within a container, you can run a host’s diagnostic binaries within a container’s namespace by using
nsenter
. The following example runsip ad
within a container’s namespace, using the host`sip
binary.Enter into a debug session on the target node. This step instantiates a debug pod called
<node_name>-debug
:$ oc debug node/my-cluster-node
Set
/host
as the root directory within the debug shell. The debug pod mounts the host’s root file system in/host
within the pod. By changing the root directory to/host
, you can run binaries contained in the host’s executable paths:# chroot /host
NoteOpenShift Container Platform 4.8 cluster nodes running Red Hat Enterprise Linux CoreOS (RHCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. However, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on the target node,
oc
operations will be impacted. In such situations, it is possible to access nodes usingssh core@<node>.<cluster_name>.<base_domain>
instead.Determine the target container ID:
# crictl ps
Determine the container’s process ID. In this example, the target container ID is
a7fe32346b120
:# crictl inspect a7fe32346b120 --output yaml | grep 'pid:' | awk '{print $2}'
Run
ip ad
within the container’s namespace, using the host’sip
binary. This example uses31150
as the container’s process ID. Thensenter
command enters the namespace of a target process and runs a command in its namespace. Because the target process in this example is a container’s process ID, theip ad
command is run in the container’s namespace from the host:# nsenter -n -t 31150 -- ip ad
NoteRunning a host’s diagnostic binaries within a container’s namespace is only possible if you are using a privileged container such as a debug node.
7.8.4. Additional resources
- See Source-to-Image (S2I) build for more details about the S2I build strategy.
7.9. Troubleshooting storage issues
7.9.1. Resolving multi-attach errors
When a node crashes or shuts down abruptly, the attached ReadWriteOnce (RWO) volume is expected to be unmounted from the node so that it can be used by a pod scheduled on another node.
However, mounting on a new node is not possible because the failed node is unable to unmount the attached volume.
A multi-attach error is reported:
Example output
Unable to attach or mount volumes: unmounted volumes=[sso-mysql-pvol], unattached volumes=[sso-mysql-pvol default-token-x4rzc]: timed out waiting for the condition Multi-Attach error for volume "pvc-8837384d-69d7-40b2-b2e6-5df86943eef9" Volume is already used by pod(s) sso-mysql-1-ns6b4
Procedure
To resolve the multi-attach issue, use one of the following solutions:
Enable multiple attachments by using RWX volumes.
For most storage solutions, you can use ReadWriteMany (RWX) volumes to prevent multi-attach errors.
Recover or delete the failed node when using an RWO volume.
For storage that does not support RWX, such as VMware vSphere, RWO volumes must be used instead. However, RWO volumes cannot be mounted on multiple nodes.
If you encounter a multi-attach error message with an RWO volume, force delete the pod on a shutdown or crashed node to avoid data loss in critical workloads, such as when dynamic persistent volumes are attached.
$ oc delete pod <old_pod> --force=true --grace-period=0
This command deletes the volumes stuck on shutdown or crashed nodes after six minutes.
7.10. Troubleshooting Windows container workload issues
7.10.1. Windows Machine Config Operator does not install
If you have completed the process of installing the Windows Machine Config Operator (WMCO), but the Operator is stuck in the InstallWaiting
phase, your issue is likely caused by a networking issue.
The WMCO requires your OpenShift Container Platform cluster to be configured with hybrid networking using OVN-Kubernetes; the WMCO cannot complete the installation process without hybrid networking available. This is necessary to manage nodes on multiple operating systems (OS) and OS variants. This must be completed during the installation of your cluster.
For more information, see Configuring hybrid networking.
7.10.2. Investigating why Windows Machine does not become compute node
There are various reasons why a Windows Machine does not become a compute node. The best way to investigate this problem is to collect the Windows Machine Config Operator (WMCO) logs.
Prerequisites
- You installed the Windows Machine Config Operator (WMCO) using Operator Lifecycle Manager (OLM).
- You have created a Windows machine set.
Procedure
Run the following command to collect the WMCO logs:
$ oc logs -f deployment/windows-machine-config-operator -n openshift-windows-machine-config-operator
7.10.3. Accessing a Windows node
Windows nodes cannot be accessed using the oc debug node
command; the command requires running a privileged pod on the node, which is not yet supported for Windows. Instead, a Windows node can be accessed using a secure shell (SSH) or Remote Desktop Protocol (RDP). An SSH bastion is required for both methods.
7.10.3.1. Accessing a Windows node using SSH
You can access a Windows node by using a secure shell (SSH).
Prerequisites
- You have installed the Windows Machine Config Operator (WMCO) using Operator Lifecycle Manager (OLM).
- You have created a Windows machine set.
-
You have added the key used in the
cloud-private-key
secret and the key used when creating the cluster to the ssh-agent. For security reasons, remember to remove the keys from the ssh-agent after use. -
You have connected to the Windows node using an
ssh-bastion
pod.
Procedure
Access the Windows node by running the following command:
$ ssh -t -o StrictHostKeyChecking=no -o ProxyCommand='ssh -A -o StrictHostKeyChecking=no \ -o ServerAliveInterval=30 -W %h:%p core@$(oc get service --all-namespaces -l run=ssh-bastion \ -o go-template="{{ with (index (index .items 0).status.loadBalancer.ingress 0) }}{{ or .hostname .ip }}{{end}}")' <username>@<windows_node_internal_ip> 1 2
$ oc get nodes <node_name> -o jsonpath={.status.addresses[?\(@.type==\"InternalIP\"\)].address}
7.10.3.2. Accessing a Windows node using RDP
You can access a Windows node by using a Remote Desktop Protocol (RDP).
Prerequisites
- You installed the Windows Machine Config Operator (WMCO) using Operator Lifecycle Manager (OLM).
- You have created a Windows machine set.
-
You have added the key used in the
cloud-private-key
secret and the key used when creating the cluster to the ssh-agent. For security reasons, remember to remove the keys from the ssh-agent after use. -
You have connected to the Windows node using an
ssh-bastion
pod.
Procedure
Run the following command to set up an SSH tunnel:
$ ssh -L 2020:<windows_node_internal_ip>:3389 \ 1 core@$(oc get service --all-namespaces -l run=ssh-bastion -o go-template="{{ with (index (index .items 0).status.loadBalancer.ingress 0) }}{{ or .hostname .ip }}{{end}}")
- 1
- Specify the internal IP address of the node, which can be discovered by running the following command:
$ oc get nodes <node_name> -o jsonpath={.status.addresses[?\(@.type==\"InternalIP\"\)].address}
From within the resulting shell, SSH into the Windows node and run the following command to create a password for the user:
C:\> net user <username> * 1
- 1
- Specify the cloud provider user name, such as
Administrator
for AWS orcapi
for Azure.
You can now remotely access the Windows node at localhost:2020
using an RDP client.
7.10.4. Collecting Kubernetes node logs for Windows containers
Windows container logging works differently from Linux container logging; the Kubernetes node logs for Windows workloads are streamed to the C:\var\logs
directory by default. Therefore, you must gather the Windows node logs from that directory.
Prerequisites
- You installed the Windows Machine Config Operator (WMCO) using Operator Lifecycle Manager (OLM).
- You have created a Windows machine set.
Procedure
To view the logs under all directories in
C:\var\logs
, run the following command:$ oc adm node-logs -l kubernetes.io/os=windows --path= \ /ip-10-0-138-252.us-east-2.compute.internal containers \ /ip-10-0-138-252.us-east-2.compute.internal hybrid-overlay \ /ip-10-0-138-252.us-east-2.compute.internal kube-proxy \ /ip-10-0-138-252.us-east-2.compute.internal kubelet \ /ip-10-0-138-252.us-east-2.compute.internal pods
You can now list files in the directories using the same command and view the individual log files. For example, to view the kubelet logs, run the following command:
$ oc adm node-logs -l kubernetes.io/os=windows --path=/kubelet/kubelet.log
7.10.5. Collecting Windows application event logs
The Get-WinEvent
shim on the kubelet logs
endpoint can be used to collect application event logs from Windows machines.
Prerequisites
- You installed the Windows Machine Config Operator (WMCO) using Operator Lifecycle Manager (OLM).
- You have created a Windows machine set.
Procedure
To view logs from all applications logging to the event logs on the Windows machine, run:
$ oc adm node-logs -l kubernetes.io/os=windows --path=journal
The same command is executed when collecting logs with
oc adm must-gather
.Other Windows application logs from the event log can also be collected by specifying the respective service with a
-u
flag. For example, you can run the following command to collect logs for the docker runtime service:$ oc adm node-logs -l kubernetes.io/os=windows --path=journal -u docker
7.10.6. Collecting Docker logs for Windows containers
The Windows Docker service does not stream its logs to stdout, but instead, logs to the event log for Windows. You can view the Docker event logs to investigate issues you think might be caused by the Windows Docker service.
Prerequisites
- You installed the Windows Machine Config Operator (WMCO) using Operator Lifecycle Manager (OLM).
- You have created a Windows machine set.
Procedure
SSH into the Windows node and enter PowerShell:
C:\> powershell
View the Docker logs by running the following command:
C:\> Get-EventLog -LogName Application -Source Docker
7.10.7. Additional resources
7.11. Investigating monitoring issues
OpenShift Container Platform includes a pre-configured, pre-installed, and self-updating monitoring stack that provides monitoring for core platform components. In OpenShift Container Platform 4.8, cluster administrators can optionally enable monitoring for user-defined projects.
You can follow these procedures if your own metrics are unavailable or if Prometheus is consuming a lot of disk space.
7.11.2. Determining why Prometheus is consuming a lot of disk space
Developers can create labels to define attributes for metrics in the form of key-value pairs. The number of potential key-value pairs corresponds to the number of possible values for an attribute. An attribute that has an unlimited number of potential values is called an unbound attribute. For example, a customer_id
attribute is unbound because it has an infinite number of possible values.
Every assigned key-value pair has a unique time series. The use of many unbound attributes in labels can result in an exponential increase in the number of time series created. This can impact Prometheus performance and can consume a lot of disk space.
You can use the following measures when Prometheus consumes a lot of disk:
- Check the number of scrape samples that are being collected.
- Check the time series database (TSDB) status in the Prometheus UI for more information on which labels are creating the most time series. This requires cluster administrator privileges.
Reduce the number of unique time series that are created by reducing the number of unbound attributes that are assigned to user-defined metrics.
NoteUsing attributes that are bound to a limited set of possible values reduces the number of potential key-value pair combinations.
- Enforce limits on the number of samples that can be scraped across user-defined projects. This requires cluster administrator privileges.
Prerequisites
-
You have access to the cluster as a user with the
cluster-admin
role. -
You have installed the OpenShift CLI (
oc
).
Procedure
- In the Administrator perspective, navigate to Monitoring → Metrics.
Run the following Prometheus Query Language (PromQL) query in the Expression field. This returns the ten metrics that have the highest number of scrape samples:
topk(10,count by (job)({__name__=~".+"}))
Investigate the number of unbound label values assigned to metrics with higher than expected scrape sample counts.
- If the metrics relate to a user-defined project, review the metrics key-value pairs assigned to your workload. These are implemented through Prometheus client libraries at the application level. Try to limit the number of unbound attributes referenced in your labels.
- If the metrics relate to a core OpenShift Container Platform project, create a Red Hat support case on the Red Hat Customer Portal.
Check the TSDB status in the Prometheus UI.
- In the Administrator perspective, navigate to Networking → Routes.
-
Select the
openshift-monitoring
project in the Project list. -
Select the URL in the
prometheus-k8s
row to open the login page for the Prometheus UI. - Choose Log in with OpenShift to log in using your OpenShift Container Platform credentials.
- In the Prometheus UI, navigate to Status → TSDB Status.
Additional resources
- See Setting a scrape sample limit for user-defined projects for details on how to set a scrape sample limit and create related alerting rules
7.12. Diagnosing OpenShift CLI (oc
) issues
7.12.1. Understanding OpenShift CLI (oc
) log levels
With the OpenShift CLI (oc
), you can create applications and manage OpenShift Container Platform projects from a terminal.
If oc
command-specific issues arise, increase the oc
log level to output API request, API response, and curl
request details generated by the command. This provides a granular view of a particular oc
command’s underlying operation, which in turn might provide insight into the nature of a failure.
oc
log levels range from 1 to 10. The following table provides a list of oc
log levels, along with their descriptions.
Log level | Description |
---|---|
1 to 5 | No additional logging to stderr. |
6 | Log API requests to stderr. |
7 | Log API requests and headers to stderr. |
8 | Log API requests, headers, and body, plus API response headers and body to stderr. |
9 |
Log API requests, headers, and body, API response headers and body, plus |
10 |
Log API requests, headers, and body, API response headers and body, plus |
7.12.2. Specifying OpenShift CLI (oc
) log levels
You can investigate OpenShift CLI (oc
) issues by increasing the command’s log level.
Prerequisites
-
Install the OpenShift CLI (
oc
).
Procedure
Specify the
oc
log level when running anoc
command:$ oc <options> --loglevel <log_level>
The OpenShift Container Platform user’s current session token is typically included in logged
curl
requests where required. You can also obtain the current user’s session token manually, for use when testing aspects of anoc
command’s underlying process step by step:$ oc whoami -t