Running applications
Running applications in MicroShift
Abstract
Chapter 1. Using Kustomize manifests to deploy applications
You can use the kustomize
configuration management tool with application manifests to deploy applications. Read through the following procedures for an example of how Kustomize works in MicroShift.
1.1. How Kustomize works with manifests to deploy applications
The kustomize
configuration management tool is integrated with MicroShift. You can use Kustomize and the OpenShift CLI (oc
) together to apply customizations to your application manifests and deploy those applications to a MicroShift cluster.
-
A
kustomization.yaml
file is a specification of resources plus customizations. -
Kustomize uses a
kustomization.yaml
file to load a resource, such as an application, then applies any changes you want to that application manifest and produces a copy of the manifest with the changes overlaid. - Using a manifest copy with an overlay keeps the original configuration file for your application intact, while enabling you to deploy iterations and customizations of your applications efficiently.
-
You can then deploy the application in your MicroShift cluster with an
oc
command.
1.1.1. How MicroShift uses manifests
At every start, MicroShift searches the following manifest directories for Kustomize manifest files:
-
/etc/microshift/manifests
-
/etc/microshift/manifests.d/*
-
/usr/lib/microshift/
-
/usr/lib/microshift/manifests.d/*
MicroShift automatically runs the equivalent of the kubectl apply -k
command to apply the manifests to the cluster if any of the following file types exists in the searched directories:
-
kustomization.yaml
-
kustomization.yml
-
Kustomization
This automatic loading from multiple directories means you can manage MicroShift workloads with the flexibility of having different workloads run independently of each other.
Location | Intent |
---|---|
| Read-write location for configuration management systems or development. |
| Read-write location for configuration management systems or development. |
| Read-only location for embedding configuration manifests on OSTree-based systems. |
| Read-only location for embedding configuration manifests on OSTree-based systems. |
1.2. Override the list of manifest paths
You can override the list of default manifest paths by using a new single path, or by using a new glob pattern for multiple files. Use the following procedure to customize your manifest paths.
Procedure
Override the list of default paths by inserting your own values and running one of the following commands:
-
Set
manifests.kustomizePaths
to<"/opt/alternate/path">
in the configuration file for a single path. Set
kustomizePaths
to,"/opt/alternative/path.d/*".
in the configuration file for a glob pattern.manifests: kustomizePaths: - <location> 1
- 1
- Set each location entry to an exact path by using
"/opt/alternate/path"
or a glob pattern by using"/opt/alternative/path.d/*"
.
-
Set
To disable loading manifests, set the configuration option to an empty list.
manifests: kustomizePaths: []
NoteThe configuration file overrides the defaults entirely. If the
kustomizePaths
value is set, only the values in the configuration file are used. Setting the value to an empty list disables manifest loading.
1.3. Using manifests example
This example demonstrates automatic deployment of a BusyBox container using kustomize
manifests in the /etc/microshift/manifests
directory.
Procedure
Create the BusyBox manifest files by running the following commands:
Define the directory location:
$ MANIFEST_DIR=/etc/microshift/manifests
Make the directory:
$ sudo mkdir -p ${MANIFEST_DIR}
Place the YAML file in the directory:
sudo tee ${MANIFEST_DIR}/busybox.yaml &>/dev/null <<EOF apiVersion: v1 kind: Namespace metadata: name: busybox --- apiVersion: apps/v1 kind: Deployment metadata: name: busybox namespace: busybox-deployment spec: selector: matchLabels: app: busybox template: metadata: labels: app: busybox spec: containers: - name: busybox image: BUSYBOX_IMAGE command: [ "/bin/sh", "-c", "while true ; do date; sleep 3600; done;" ] EOF
Next, create the
kustomize
manifest files by running the following commands:Place the YAML file in the directory:
sudo tee ${MANIFEST_DIR}/kustomization.yaml &>/dev/null <<EOF apiVersion: kustomize.config.k8s.io/v1beta1 kind: Kustomization namespace: busybox resources: - busybox.yaml images: - name: BUSYBOX_IMAGE newName: busybox:1.35 EOF
Restart MicroShift to apply the manifests by running the following command:
$ sudo systemctl restart microshift
Apply the manifests and start the
busybox
pod by running the following command:$ oc get pods -n busybox
Chapter 2. Options for embedding applications in a RHEL for Edge image
You can embed microservices-based workloads and applications in a Red Hat Enterprise Linux for Edge (RHEL for Edge) image to run in a MicroShift cluster. Embedded applications can be installed directly on edge devices to run in disconnected or offline environments.
2.1. Adding application RPMs to an rpm-ostree image
If you have an application that includes APIs, container images, and configuration files for deployment such as manifests, you can build application RPMs. You can then add the RPMs to your RHEL for Edge system image.
The following is an outline of the procedures to embed applications or workloads in a fully self-contained operating system image:
- Build your own RPM that includes your application manifest.
- Add the RPM to the blueprint you used to install Red Hat build of MicroShift.
- Add the workload container images to the same blueprint.
- Create a bootable ISO.
For a step-by-step tutorial about preparing and embedding applications in a RHEL for Edge image, use the following tutorial:
2.2. Adding application manifests to an image for offline use
If you have a simple application that includes a few files for deployment such as manifests, you can add those manifests directly to a RHEL for Edge system image.
See the "Create a custom file blueprint customization" section of the following RHEL for Edge documentation for an example:
2.3. Embedding applications for offline use
If you have an application that includes more than a few files, you can embed the application for offline use. See the following procedure:
2.4. Additional resources
Chapter 3. Embedding applications for offline use
You can embed microservices-based workloads and applications in a Red Hat Enterprise Linux for Edge (RHEL for Edge) image. Embedding means you can run a Red Hat build of MicroShift cluster in air-gapped, disconnected, or offline environments.
3.1. Embedding workload container images for offline use
To embed container images in devices at the edge that do not have any network connection, you must create a new container, mount the ISO, and then copy the contents into the file system.
Prerequisites
- You have root access to the host.
- Application RPMs have been added to a blueprint.
-
You installed the OpenShift CLI (
oc
).
Procedure
Render the manifests, extract all of the container image references, and translate the application image to blueprint container sources by running the following command:
$ oc kustomize ~/manifests | grep "image:" | grep -oE '[^ ]+$' | while read line; do echo -e "[[containers]]\nsource = \"${line}\"\n"; done >><my_blueprint>.toml
Push the updated blueprint to image builder by running the following command:
$ sudo composer-cli blueprints push <my_blueprint>.toml
If your workload containers are located in a private repository, you must provide image builder with the necessary pull secrets:
-
Set the
auth_file_path
in the[containers]
section of theosbuilder worker
configuration in the/etc/osbuild-worker/osbuild-worker.toml
file to point to the pull secret. If needed, create a directory and file for the pull secret, for example:
Example directory and file
[containers] auth_file_path = "/<path>/pull-secret.json" 1
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- Use the custom location previously set for copying and retrieving images.
-
Set the
Build the container image by running the following command:
$ sudo composer-cli compose start-ostree <my_blueprint> edge-commit
-
Proceed with your preferred
rpm-ostree
image flow, such as waiting for the build to complete, exporting the image and integrating it into yourrpm-ostree
repository or creating a bootable ISO.
3.2. Additional resources
Chapter 4. Embedding MicroShift applications tutorial
The following tutorial gives a detailed example of how to embed applications in a RHEL for Edge image for use in a MicroShift cluster in various environments.
4.1. Embed application RPMs tutorial
The following tutorial reviews the MicroShift installation steps and adds a description of the workflow for embedding applications. If you are already familiar with rpm-ostree
systems such as Red Hat Enterprise Linux for Edge (RHEL for Edge) and MicroShift, you can go straight to the procedures.
4.1.1. Installation workflow review
Embedding applications requires a similar workflow to embedding MicroShift into a RHEL for Edge image.
- The following image shows how system artifacts such as RPMs, containers, and files are added to a blueprint and used by the image composer to create an ostree commit.
- The ostree commit then can follow either the ISO path or the repository path to edge devices.
- The ISO path can be used for disconnected environments, while the repository path is often used in places were the network is usually connected.
Embedding MicroShift workflow
Reviewing these steps can help you understand the steps needed to embed an application:
- To embed MicroShift on RHEL for Edge, you added the MicroShift repositories to Image Builder.
- You created a blueprint that declared all the RPMs, container images, files and customizations you needed, including the addition of MicroShift.
-
You added the blueprint to Image Builder and ran a build with the Image Builder CLI tool (
composer-cli
). This step createdrpm-ostree
commits, which were used to create the container image. This image contained RHEL for Edge. -
You added the installer blueprint to Image Builder to create an
rpm-ostree
image (ISO) to boot from. This build contained both RHEL for Edge and MicroShift. - You downloaded the ISO with MicroShift embedded, prepared it for use, provisioned it, then installed it onto your edge devices.
4.1.2. Embed application RPMs workflow
After you have set up a build host that meets the Image Builder requirements, you can add your application in the form of a directory of manifests to the image. After those steps, the simplest way to embed your application or workload into a new ISO is to create your own RPMs that include the manifests. Your application RPMs contain all of the configuration files describing your deployment.
The following "Embedding applications workflow" image shows how Kubernetes application manifests and RPM spec files are combined in a single application RPM build. This build becomes the RPM artifact included in the workflow for embedding MicroShift in an ostree commit.
Embedding applications workflow
The following procedures use the rpmbuild
tool to create a specification file and local repository. The specification file defines how the package is built, moving your application manifests to the correct location inside the RPM package for MicroShift to pick them up. That RPM package is then embedded in the ISO.
4.1.3. Preparing to make application RPMs
To build your own RPMs, choose a tool of your choice, such as the rpmbuild
tool, and initialize the RPM build tree in your home directory. The following is an example procedure. As long as your RPMs are accessible to image builder, you can use the method you prefer to build the application RPMs.
Prerequisites
- You have set up a Red Hat Enterprise Linux for Edge (RHEL for Edge) 9.4 build host that meets the image builder system requirements.
- You have root access to the host.
Procedure
Install the
rpmbuild
tool and create the yum repository for it by running the following command:$ sudo dnf install rpmdevtools rpmlint yum-utils createrepo
Create the file tree you need to build RPM packages by running the following command:
$ rpmdev-setuptree
Verification
List the directories to confirm creation by running the following command:
$ ls ~/rpmbuild/
Example output
BUILD RPMS SOURCES SPECS SRPMS
4.1.4. Building the RPM package for the application manifests
To build your own RPMs, you must create a spec file that adds the application manifests to the RPM package. The following is an example procedure. As long as the application RPMs and other elements needed for image building are accessible to image builder, you can use the method that you prefer.
Prerequisites
- You have set up a Red Hat Enterprise Linux for Edge (RHEL for Edge) 9.4 build host that meets the image builder system requirements.
- You have root access to the host.
- The file tree required to build RPM packages was created.
Procedure
In the
~/rpmbuild/SPECS
directory, create a file such as<application_workload_manifests.spec>
using the following template:Example spec file
Name: <application_workload_manifests> Version: 0.0.1 Release: 1%{?dist} Summary: Adds workload manifests to microshift BuildArch: noarch License: GPL Source0: %{name}-%{version}.tar.gz #Requires: microshift %description Adds workload manifests to microshift %prep %autosetup %install 1 rm -rf $RPM_BUILD_ROOT mkdir -p $RPM_BUILD_ROOT/%{_prefix}/lib/microshift/manifests cp -pr ~/manifests $RPM_BUILD_ROOT/%{_prefix}/lib/microshift/ %clean rm -rf $RPM_BUILD_ROOT %files %{_prefix}/lib/microshift/manifests/** %changelog * <DDD MM DD YYYY username@domain - V major.minor.patch> - <your_change_log_comment>
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- The
%install
section creates the target directory inside the RPM package,/usr/lib/microshift/manifests/
and copies the manifests from the source home directory,~/manifests
.
ImportantAll of the required YAML files must be in the source home directory
~/manifests
, including akustomize.yaml
file if you are using kustomize.Build your RPM package in the
~/rpmbuild/RPMS
directory by running the following command:$ rpmbuild -bb ~/rpmbuild/SPECS/<application_workload_manifests.spec>
4.1.5. Adding application RPMs to a blueprint
To add application RPMs to a blueprint, you must create a local repository that Image Builder can use to create the ISO. With this procedure, the required container images for your workload can be pulled over the network.
Prerequisites
- You have root access to the host.
-
Workload or application RPMs exist in the
~/rpmbuild/RPMS
directory.
Procedure
Create a local RPM repository by running the following command:
$ createrepo ~/rpmbuild/RPMS/
Give image builder access to the RPM repository by running the following command:
$ sudo chmod a+rx ~
NoteYou must ensure that image builder has all of the necessary permissions to access all of the files needed for image building, or the build cannot proceed.
Create the blueprint file,
repo-local-rpmbuild.toml
using the following template:id = "local-rpm-build" name = "RPMs build locally" type = "yum-baseurl" url = "file://<path>/rpmbuild/RPMS" 1 check_gpg = false check_ssl = false system = false
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- Specify part of the path to create a location that you choose. Use this path in the later commands to set up the repository and copy the RPMs.
Add the repository as a source for image builder by running the following command:
$ sudo composer-cli sources add repo-local-rpmbuild.toml
Add the RPM to your blueprint, by adding the following lines:
… [[packages]] name = "<application_workload_manifests>" 1 version = "*" …
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- Add the name of your workload here.
Push the updated blueprint to image builder by running the following command:
$ sudo composer-cli blueprints push repo-local-rpmbuild.toml
At this point, you can either run image builder to create the ISO, or embed the container images for offline use.
To create the ISO, start image builder by running the following command:
$ sudo composer-cli compose start-ostree repo-local-rpmbuild edge-commit
In this scenario, the container images are pulled over the network by the edge device during startup.
4.2. Additional resources
- Embedding applications for offline use
- Embedding Red Hat build of MicroShift in an RPM-OSTree image
- Composing, installing, and managing RHEL for Edge images
- Preparing for image building
- Meet Red Hat Device Edge with Red Hat build of MicroShift
- How to create a Linux RPM package
- Composing a RHEL for Edge image using image builder command-line
- Image Builder system requirements
Chapter 5. Greenboot workload health check scripts
Greenboot health check scripts are helpful on edge devices where direct serviceability is either limited or non-existent. You can create health check scripts to assess the health of your workloads and applications. These additional health check scripts are useful components of software problem checks and automatic system rollbacks.
A MicroShift health check script is included in the microshift-greenboot
RPM. You can also create your own health check scripts based on the workloads you are running. For example, you can write one that verifies that a service has started.
5.1. How workload health check scripts work
The workload or application health check script described in this tutorial uses the MicroShift health check functions that are available in the /usr/share/microshift/functions/greenboot.sh
file. This enables you to reuse procedures already implemented for the MicroShift core services.
The script starts by running checks that the basic functions of the workload are operating as expected. To run the script successfully:
- Execute the script from a root user account.
- Enable the MicroShift service.
The health check performs the following actions:
-
Gets a wait timeout of the current boot cycle for the
wait_for
function. -
Calls the
namespace_images_downloaded
function to wait until pod images are available. -
Calls the
namespace_pods_ready
function to wait until pods are ready. -
Calls the
namespace_pods_not_restarting
function to verify pods are not restarting.
Restarting pods can indicate a crash loop.
5.2. Included greenboot health checks
Health check scripts are available in /usr/lib/greenboot/check
, a read-only directory in RPM-OSTree systems. The following health checks are included with the greenboot-default-health-checks
framework.
Check if repository URLs are still DNS solvable:
This script is under
/usr/lib/greenboot/check/required.d/01_repository_dns_check.sh
and ensures that DNS queries to repository URLs are still available.Check if update platforms are still reachable:
This script is under
/usr/lib/greenboot/check/wanted.d/01_update_platform_check.sh
and tries to connect and get a 2XX or 3XX HTTP code from the update platforms defined in/etc/ostree/remotes.d
.Check if the current boot has been triggered by the hardware watchdog:
This script is under
/usr/lib/greenboot/check/required.d/02_watchdog.sh
and checks whether the current boot has been watchdog-triggered or not.- If the watchdog-triggered reboot occurs within the grace period, the current boot is marked as red. Greenboot does not trigger a rollback to the previous deployment.
- If the watchdog-triggered reboot occurs after the grace period, the current boot is not marked as red. Greenboot does not trigger a rollback to the previous deployment.
-
A 24-hour grace period is enabled by default. This grace period can be either disabled by modifying
GREENBOOT_WATCHDOG_CHECK_ENABLED
in/etc/greenboot/greenboot.conf to false
, or configured by changing theGREENBOOT_WATCHDOG_GRACE_PERIOD=number_of_hours
variable value in/etc/greenboot/greenboot.conf
.
5.3. How to create a health check script for your application
You can create workload or application health check scripts in the text editor of your choice using the example in this documentation. Save the scripts in the /etc/greenboot/check/required.d
directory. When a script in the /etc/greenboot/check/required.d
directory exits with an error, greenboot triggers a reboot in an attempt to heal the system.
Any script in the /etc/greenboot/check/required.d
directory triggers a reboot if it exits with an error.
If your health check logic requires any post-check steps, you can also create additional scripts and save them in the relevant greenboot directories. For example:
-
You can also place shell scripts you want to run after a boot has been declared successful in
/etc/greenboot/green.d
. -
You can place shell scripts you want to run after a boot has been declared failed in
/etc/greenboot/red.d
. For example, if you have steps to heal the system before restarting, you can create scripts for your use case and place them in the/etc/greenboot/red.d
directory.
5.3.1. About the workload health check script example
The following example uses the MicroShift health check script as a template. You can use this example with the provided libraries as a guide for creating basic health check scripts for your applications.
5.3.1.1. Basic prerequisites for creating a health check script
- The workload must be installed.
- You must have root access.
5.3.1.2. Example and functional requirements
You can start with the following example health check script. Modify it for your use case. In your workload health check script, you must complete the following minimum steps:
- Set the environment variables.
- Define the user workload namespaces.
- List the expected pod count.
Choose a name prefix for your application that ensures it runs after the 40_microshift_running_check.sh
script, which implements the Red Hat build of MicroShift health check procedure for its core services.
Example workload health check script
# #!/bin/bash set -e SCRIPT_NAME=$(basename $0) PODS_NS_LIST=(<user_workload_namespace1> <user_workload_namespace2>) PODS_CT_LIST=(<user_workload_namespace1_pod_count> <user_workload_namespace2_pod_count>) # Update these two lines with at least one namespace and the pod counts that are specific to your workloads. Use the kubernetes <namespace> where your workload is deployed. # Set greenboot to read and execute the workload health check functions library. source /usr/share/microshift/functions/greenboot.sh # Set the exit handler to log the exit status. trap 'script_exit' EXIT # Set the script exit handler to log a `FAILURE` or `FINISHED` message depending on the exit status of the last command. # args: None # return: None function script_exit() { [ "$?" -ne 0 ] && status=FAILURE || status=FINISHED echo $status } # Set the system to automatically stop the script if the user running it is not 'root'. if [ $(id -u) -ne 0 ] ; then echo "The '${SCRIPT_NAME}' script must be run with the 'root' user privileges" exit 1 fi echo "STARTED" # Set the script to stop without reporting an error if the MicroShift service is not running. if [ $(systemctl is-enabled microshift.service 2>/dev/null) != "enabled" ] ; then echo "MicroShift service is not enabled. Exiting..." exit 0 fi # Set the wait timeout for the current check based on the boot counter. WAIT_TIMEOUT_SECS=$(get_wait_timeout) # Set the script to wait for the pod images to be downloaded. for i in ${!PODS_NS_LIST[@]}; do CHECK_PODS_NS=${PODS_NS_LIST[$i]} echo "Waiting ${WAIT_TIMEOUT_SECS}s for pod image(s) from the ${CHECK_PODS_NS} namespace to be downloaded" wait_for ${WAIT_TIMEOUT_SECS} namespace_images_downloaded done # Set the script to wait for pods to enter ready state. for i in ${!PODS_NS_LIST[@]}; do CHECK_PODS_NS=${PODS_NS_LIST[$i]} CHECK_PODS_CT=${PODS_CT_LIST[$i]} echo "Waiting ${WAIT_TIMEOUT_SECS}s for ${CHECK_PODS_CT} pod(s) from the ${CHECK_PODS_NS} namespace to be in 'Ready' state" wait_for ${WAIT_TIMEOUT_SECS} namespace_pods_ready done # Verify that pods are not restarting by running, which could indicate a crash loop. for i in ${!PODS_NS_LIST[@]}; do CHECK_PODS_NS=${PODS_NS_LIST[$i]} echo "Checking pod restart count in the ${CHECK_PODS_NS} namespace" namespace_pods_not_restarting ${CHECK_PODS_NS} done
5.4. Testing a workload health check script
Prerequisites
- You have root access.
- You have installed a workload.
- You have created a health check script for the workload.
- The Red Hat build of MicroShift service is enabled.
Procedure
To test that greenboot is running a health check script file, reboot the host by running the following command:
$ sudo reboot
Examine the output of greenboot health checks by running the following command:
$ sudo journalctl -o cat -u greenboot-healthcheck.service
NoteMicroShift core service health checks run before the workload health checks.
Example output
GRUB boot variables: boot_success=0 boot_indeterminate=0 Greenboot variables: GREENBOOT_WATCHDOG_CHECK_ENABLED=true ... ... FINISHED Script '40_microshift_running_check.sh' SUCCESS Running Wanted Health Check Scripts... Finished greenboot Health Checks Runner.
5.5. Additional resources
Chapter 6. Automating application management with the GitOps controller
GitOps with Argo CD for MicroShift is a lightweight, optional add-on controller derived from the Red Hat OpenShift GitOps Operator. GitOps for MicroShift uses the command-line interface (CLI) of Argo CD to interact with the GitOps controller that acts as the declarative GitOps engine. You can consistently configure and deploy Kubernetes-based infrastructure and applications across clusters and development lifecycles.
6.1. What you can do with the GitOps agent
By using the GitOps with Argo CD agent with MicroShift, you can utilize the following principles:
Implement application lifecycle management.
- Create and manage your clusters and application configuration files using the core principles of developing and maintaining software in a Git repository.
- You can update the single repository and GitOps automates the deployment of new applications or updates to existing ones.
- For example, if you have 1,000 edge devices, each using MicroShift and a local GitOps agent, you can easily add or update an application on all 1,000 devices with just one change in your central Git repository.
- The Git repository contains a declarative description of the infrastructure you need in your specified environment and contains an automated process to make your environment match the described state.
- You can also use the Git repository as an audit trail of changes so that you can create processes based on Git flows such as review and approval for merging pull requests that implement configuration changes.
6.2. Creating GitOps applications on MicroShift
You can create a custom YAML configuration to deploy and manage applications in your MicroShift service. To install the necessary packages to run GitOps applications, follow the documentation in "Installing the GitOps Argo CD manifests from an RPM package".
Prerequisites
-
You installed the
microshift-gitops
packages. -
The Argo CD pods are running in the
openshift-gitops
namespace.
Procedure
Create a YAML file and add your customized configurations for the application:
Example YAML for a
spring-petclinic
applicationkind: AppProject apiVersion: argoproj.io/v1alpha1 metadata: name: default namespace: openshift-gitops spec: clusterResourceWhitelist: - group: '*' kind: '*' destinations: - namespace: '*' server: '*' sourceRepos: - '*' --- kind: Application apiVersion: argoproj.io/v1alpha1 metadata: name: spring-petclinic namespace: openshift-gitops spec: destination: namespace: spring-petclinic server: https://kubernetes.default.svc project: default source: directory: recurse: true path: app repoURL: https://github.com/siamaksade/openshift-gitops-getting-started syncPolicy: automated: {} syncOptions: - CreateNamespace=true - ServerSideApply=true
To deploy the applications defined in the YAML file, run the following command:
$ oc apply -f <my_app.yaml> 1
- 1
- Replace
<my_app.yaml>
with the name of your application YAML.
Verification
To verify your application is deployed and synced, run the following command:
$ oc get applications -A
It might take a few minutes for the application to show the
Healthy
status.Example output
NAMESPACE NAME SYNC STATUS HEALTH STATUS openshift-gitops spring-petclinic Synced Healthy
Additional resources
6.3. Limitations of using the GitOps agent with MicroShift
GitOps with Argo CD for MicroShift has the following differences from the Red Hat OpenShift GitOps Operator:
-
The
gitops-operator
component is not used with MicroShift. - To maintain the small resource use of MicroShift, the Argo CD web console is not available. You can use the Argo CD CLI.
- Because MicroShift is single-node, there is no multi-cluster support. Each instance of MicroShift is paired with a local GitOps agent.
-
The
oc adm must-gather
command is not available in MicroShift.
6.4. Troubleshooting GitOps
If you have problems with your GitOps controller, you can use the OpenShift CLI (oc
) tool.
6.4.1. Debugging GitOps with oc adm inspect
You can debug GitOps by using the OpenShift CLI (oc
).
Prerequisites
-
The
oc
command line tool is installed.
Procedure
Run the
oc adm inspect
command when in the GitOps namespace:$ oc adm inspect ns/openshift-gitops
Example output
Gathering data for ns/openshift-gitops... W0501 20:34:35.978508 57625 util.go:118] the server doesn't have a resource type egressfirewalls, skipping the inspection W0501 20:34:35.980881 57625 util.go:118] the server doesn't have a resource type egressqoses, skipping the inspection W0501 20:34:36.040664 57625 util.go:118] the server doesn't have a resource type servicemonitors, skipping the inspection Wrote inspect data to inspect.local.2673575938140296280.
Next steps
-
If
oc adm inspect
did not provide the information you need, you can run an sos report.
6.5. Additional resources
Chapter 7. Pod security authentication and authorization
Pod security admission is an implementation of the Kubernetes pod security standards. Use pod security admission to restrict the behavior of pods.
7.1. Security context constraint synchronization with pod security standards
MicroShift includes Kubernetes pod security admission.
In addition to the global pod security admission control configuration, a controller exists that applies pod security admission control warn
and audit
labels to namespaces according to the security context constraint (SCC) permissions of the service accounts that are in a given namespace.
Namespaces that are defined as part of the cluster payload have pod security admission synchronization disabled permanently. You can enable pod security admission synchronization on other namespaces as necessary. If an Operator is installed in a user-created openshift-*
namespace, synchronization is turned on by default after a cluster service version (CSV) is created in the namespace.
The controller examines ServiceAccount
object permissions to use security context constraints in each namespace. Security context constraints (SCCs) are mapped to pod security profiles based on their field values; the controller uses these translated profiles. Pod security admission warn
and audit
labels are set to the most privileged pod security profile found in the namespace to prevent warnings and audit logging as pods are created.
Namespace labeling is based on consideration of namespace-local service account privileges.
Applying pods directly might use the SCC privileges of the user who runs the pod. However, user privileges are not considered during automatic labeling.
7.1.1. Viewing security context constraints in a namespace
You can view the security context constraints (SCC) permissions in a given namespace.
Prerequisites
-
You have installed the OpenShift CLI (
oc
).
Procedure
To view the security context constraints in your namespace, run the following command:
oc get --show-labels namespace <namespace>
7.2. Controlling pod security admission synchronization
You can enable automatic pod security admission synchronization for most namespaces.
System defaults are not enforced when the security.openshift.io/scc.podSecurityLabelSync
field is empty or set to false
. You must set the label to true
for synchronization to occur.
Namespaces that are defined as part of the cluster payload have pod security admission synchronization disabled permanently. These namespaces include:
-
default
-
kube-node-lease
-
kube-system
-
kube-public
-
openshift
-
All system-created namespaces that are prefixed with
openshift-
, except foropenshift-operators
By default, all namespaces that have anopenshift-
prefix are not synchronized. You can enable synchronization for any user-createdopenshift-*
namespaces. You cannot enable synchronization for any system-createdopenshift-*
namespaces, except foropenshift-operators
.
If an Operator is installed in a user-created openshift-*
namespace, synchronization is turned on by default after a cluster service version (CSV) is created in the namespace. The synchronized label inherits the permissions of the service accounts in the namespace.
Procedure
To enable pod security admission label synchronization in a namespace, set the value of the
security.openshift.io/scc.podSecurityLabelSync
label totrue
.Run the following command:
$ oc label namespace <namespace> security.openshift.io/scc.podSecurityLabelSync=true
You can use the --overwrite flag to reverse the effects of the pod security label synchronization in a namespace.
Chapter 8. Operators
8.1. Using Operators with MicroShift
You can use Operators with MicroShift to create applications that monitor the running services in your cluster. Operators can manage applications and their resources, such as deploying a database or message bus. As customized software running inside your cluster, Operators can be used to implement and automate common operations.
Operators offer a more localized configuration experience and integrate with Kubernetes APIs and CLI tools such as kubectl
and oc
. Operators are designed specifically for your applications. Operators enable you to configure components instead of modifying a global configuration file.
MicroShift applications are generally expected to be deployed in static environments. However, Operators are available if helpful in your use case. To determine the compatibility of an Operator with MicroShift, check the Operator documentation.
8.1.1. How to use Operators with MicroShift clusters
There are two ways to use Operators for your MicroShift clusters:
8.1.1.1. Manifests for Operators
Operators can be installed and managed directly by using manifests. You can use the kustomize
configuration management tool with MicroShift to deploy an application. Use the same steps to install Operators with manifests.
- See Using Kustomize manifests to deploy applications and Using manifests example for details.
8.1.1.2. Operator Lifecycle Manager for Operators
You can also install add-on Operators to a MicroShift cluster using Operator Lifecycle Manager (OLM). OLM can be used to manage both custom Operators and Operators that are widely available. Building catalogs is required to use OLM with MicroShift.
- For details, see Using Operator Lifecycle Manager with MicroShift.
8.2. Using Operator Lifecycle Manager with MicroShift
The Operator Lifecycle Manager (OLM) package manager is used in MicroShift for installing and running optional add-on Operators.
8.2.1. Considerations for using OLM with MicroShift
- Cluster Operators as applied in OpenShift Container Platform are not used in MicroShift.
You must create your own catalogs for the add-on Operators you want to use with your applications. Catalogs are not provided by default.
-
Each catalog must have an accessible
CatalogSource
added to a cluster, so that the OLM catalog Operator can use the catalog for content.
-
Each catalog must have an accessible
You must use the CLI to conduct OLM activities with MicroShift. The console and OperatorHub GUIs are not available.
-
Use the Operator Package Manager
opm
CLI with network-connected clusters, or for building catalogs for custom Operators that use an internal registry. - To mirror your catalogs and Operators for disconnected or offline clusters, install the oc-mirror OpenShift CLI plugin.
-
Use the Operator Package Manager
Before using an Operator, verify with the provider that the Operator is supported on Red Hat build of MicroShift.
8.2.2. Determining your OLM installation type
You can install the OLM package manager for use with MicroShift 4.15 or newer versions. There are different ways to install OLM for MicroShift clusters, depending on your use case.
-
You can install the
microshift-olm
RPM at the same time you install the MicroShift RPM on Red Hat Enterprise Linux (RHEL). -
You can install the
microshift-olm
on an existing MicroShift 4.17. Restart the MicroShift service after installing OLM for the changes to apply. See Installing the Operator Lifecycle Manager (OLM) from an RPM package. - You can embed OLM in a Red Hat Enterprise Linux for Edge (RHEL for Edge) image. See Adding the Operator Lifecycle Manager (OLM) service to a blueprint.
8.2.3. Namespace use in MicroShift
The microshift-olm
RPM creates the three default namespaces: one for running OLM, and two for catalog and Operator installation. You can create additional namespaces as needed for your use case.
8.2.3.1. Default namespaces
The following table lists the default namespaces and a brief description of how each namespace works.
Default Namespace | Details |
| The OLM package manager runs in this namespace. |
|
The global namespace. Empty by default. To make the catalog source to be available globally to users in all namespaces, set the |
|
The default namespace where Operators run in MicroShift. Operators that reference catalogs in the |
8.2.3.2. Custom namespaces
If you want to use a catalog and Operator together in a single namespace, then you must create a custom namespace. After you create the namespace, you must create the catalog in that namespace. All Operators running in the custom namespace must have the same single-namespace watch scope.
8.2.4. About building Operator catalogs
To use Operator Lifecycle Manager (OLM) with MicroShift, you must build custom Operator catalogs that you can then manage with OLM. The standard catalogs that are included with OpenShift Container Platform are not included with MicroShift.
8.2.4.1. File-based Operator catalogs
You can create catalogs for your custom Operators or filter catalogs of widely available Operators. You can combine both methods to create the catalogs needed for your specific use case. To run MicroShift with your own Operators and OLM, make a catalog by using the file-based catalog structure.
- For details, see Managing custom catalogs and Example catalog.
-
See also
opm
CLI reference.
-
When adding a catalog source to a cluster, set the
securityContextConfig
value torestricted
in thecatalogSource.yaml
file. Ensure that your catalog can run withrestricted
permissions.
Additional resources
-
opm
CLI reference - About Operator catalogs
-
To create file-based catalogs by using the
opm
CLI, see Managing custom catalogs
8.2.5. How to deploy Operators using OLM
After you create and deploy your custom catalog, you must create a Subscription custom resource (CR) that can access the catalog and install the Operators you choose. Where Operators run depends on the namespace in which you create the Subscription CR.
Operators in OLM have a watch scope. For example, some Operators only support watching their own namespace, while others support watching every namespace in the cluster. All Operators installed in a given namespace must have the same watch scope.
8.2.5.1. Connectivity and OLM Operator deployment
Operators can be deployed anywhere a catalog is running.
- For clusters that are connected to the internet, mirroring images is not required. Images can be pulled over the network.
- For restricted networks in which MicroShift has access to an internal network only, images must be mirrored to an internal registry.
-
For use cases in which MicroShift clusters are completely offline, all images must be embedded into an
osbuild
blueprint.
Additional resources
8.2.5.2. Adding OLM-based Operators to a networked cluster using the global namespace
To deploy different operators to different namespaces, use this procedure. For MicroShift clusters that have network connectivity, Operator Lifecycle Manager (OLM) can access sources hosted on remote registries. The following procedure lists the basic steps of using configuration files to install an Operator that uses the global namespace.
To use an Operator installed in a different namespace, or in more than one namespace, make sure that the catalog source and the Subscription CR that references the Operator are running in the openshift-marketplace
namespace.
Prerequisites
-
The OpenShift CLI (
oc
) is installed. - Operator Lifecycle Manager (OLM) is installed.
- You have created a custom catalog in the global namespace.
Procedure
Confirm that OLM is running by using the following command:
$ oc -n openshift-operator-lifecycle-manager get pod -l app=olm-operator
Example output
NAME READY STATUS RESTARTS AGE olm-operator-85b5c6786-n6kbc 1/1 Running 0 2m24s
Confirm that the OLM catalog Operator is running by using the following command:
$ oc -n openshift-operator-lifecycle-manager get pod -l app=catalog-operator
Example output
NAME READY STATUS RESTARTS AGE catalog-operator-5fc7f857b6-tj8cf 1/1 Running 0 2m33s
The following steps assume you are using the global namespace, openshift-marketplace
. The catalog must run in the same namespace as the Operator. The Operator must support the AllNamespaces mode.
Create the
CatalogSource
object by using the following example YAML:Example catalog source YAML
apiVersion: operators.coreos.com/v1alpha1 kind: CatalogSource metadata: name: operatorhubio-catalog namespace: openshift-marketplace 1 spec: sourceType: grpc image: quay.io/operatorhubio/catalog:latest displayName: Community Operators 2 publisher: OperatorHub.io grpcPodConfig: securityContextConfig: restricted 3 updateStrategy: registryPoll: interval: 60m
- 1
- The global namespace. Setting the
metadata.namespace
toopenshift-marketplace
enables the catalog to run in all namespaces. Subscriptions in any namespace can reference catalogs created in theopenshift-marketplace
namespace. - 2
- Community Operators are not installed by default with OLM for MicroShift. Listed here for example only.
- 3
- The value of
securityContextConfig
must be set torestricted
for MicroShift.
Apply the
CatalogSource
configuration by running the following command:$ oc apply -f <catalog_source.yaml> 1
- 1
- Replace
<catalog-source.yaml>
with your catalog source configuration file name. In this example,catalogsource.yaml
is used.
Example output
catalogsource.operators.coreos.com/operatorhubio-catalog created
To verify that the catalog source is applied, check for the
READY
state by using the following command:$ oc describe catalogsources.operators.coreos.com -n openshift-marketplace operatorhubio-catalog
Example output
Name: operatorhubio-catalog Namespace: openshift-marketplace Labels: <none> Annotations: <none> API Version: operators.coreos.com/v1alpha1 Kind: CatalogSource Metadata: Creation Timestamp: 2024-01-31T09:55:31Z Generation: 1 Resource Version: 1212 UID: 4edc1a96-83cd-4de9-ac8c-c269ca895f3e Spec: Display Name: Community Operators Grpc Pod Config: Security Context Config: restricted Image: quay.io/operatorhubio/catalog:latest Publisher: OperatorHub.io Source Type: grpc Update Strategy: Registry Poll: Interval: 60m Status: Connection State: Address: operatorhubio-catalog.openshift-marketplace.svc:50051 Last Connect: 2024-01-31T09:55:57Z Last Observed State: READY 1 Registry Service: Created At: 2024-01-31T09:55:31Z Port: 50051 Protocol: grpc Service Name: operatorhubio-catalog Service Namespace: openshift-marketplace Events: <none>
- 1
- The status is reported as
READY
.
Confirm that the catalog source is running by using the following command:
$ oc get pods -n openshift-marketplace -l olm.catalogSource=operatorhubio-catalog
Example output
NAME READY STATUS RESTARTS AGE operatorhubio-catalog-x24nh 1/1 Running 0 59s
Create a Subscription CR configuration file by using the following example YAML:
Example Subscription custom resource YAML
apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: my-cert-manager namespace: openshift-operators spec: channel: stable name: cert-manager source: operatorhubio-catalog sourceNamespace: openshift-marketplace 1
- 1
- The global namespace. Setting the
sourceNamespace
value toopenshift-marketplace
enables Operators to run in multiple namespaces if the catalog also runs in theopenshift-marketplace
namespace.
Apply the Subscription CR configuration by running the following command:
$ oc apply -f <subscription_cr.yaml> 1
- 1
- Replace
<subscription_cr.yaml>
with your Subscription CR filename.
Example output
subscription.operators.coreos.com/my-cert-manager created
- You can create a configuration file for the specific Operand you want to use and apply it now.
Verification
Verify that your Operator is running by using the following command:
$ oc get pods -n openshift-operators 1
- 1
- The namespace from the Subscription CR is used.
NoteAllow a minute or two for the Operator start.
Example output
NAME READY STATUS RESTARTS AGE cert-manager-7df8994ddb-4vrkr 1/1 Running 0 19s cert-manager-cainjector-5746db8fd7-69442 1/1 Running 0 18s cert-manager-webhook-f858bf58b-748nt 1/1 Running 0 18s
8.2.5.3. Adding OLM-based Operators to a networked cluster in a specific namespace
Use this procedure if you want to specify a namespace for an Operator, for example, olm-microshift
. In this example, the catalog is scoped and available in the global openshift-marketplace
namespace. The Operator uses content from the global namespace, but runs only in the olm-microshift
namespace. For MicroShift clusters that have network connectivity, Operator Lifecycle Manager (OLM) can access sources hosted on remote registries.
All of the Operators installed in a specific namespace must have the same watch scope. In this case, the watch scope is OwnNamespace.
Prerequisites
-
The OpenShift CLI (
oc
) is installed. - Operator Lifecycle Manager (OLM) is installed.
- You have created a custom catalog that is running in the global namespace.
Procedure
Confirm that OLM is running by using the following command:
$ oc -n openshift-operator-lifecycle-manager get pod -l app=olm-operator
Example output
NAME READY STATUS RESTARTS AGE olm-operator-85b5c6786-n6kbc 1/1 Running 0 16m
Confirm that the OLM catalog Operator is running by using the following command:
$ oc -n openshift-operator-lifecycle-manager get pod -l app=catalog-operator
Example output
NAME READY STATUS RESTARTS AGE catalog-operator-5fc7f857b6-tj8cf 1/1 Running 0 16m
Create a namespace by using the following example YAML:
Example namespace YAML
apiVersion: v1 kind: Namespace metadata: name: olm-microshift
Apply the namespace configuration using the following command:
$ oc apply -f <ns.yaml> 1
- 1
- Replace
<ns.yaml>
with the name of your namespace configuration file. In this example,olm-microshift
is used.
Example output
namespace/olm-microshift created
Create the Operator group YAML by using the following example YAML:
Example Operator group YAML
kind: OperatorGroup apiVersion: operators.coreos.com/v1 metadata: name: og namespace: olm-microshift spec: 1 targetNamespaces: - olm-microshift
- 1
- For Operators using the global namespace, omit the
spec.targetNamespaces
field and values.
Apply the Operator group configuration by running the following command:
$ oc apply -f <og.yaml> 1
- 1
- Replace
<og.yaml>
with the name of your operator group configuration file.
Example output
operatorgroup.operators.coreos.com/og created
Create the
CatalogSource
object by using the following example YAML:Example catalog source YAML
apiVersion: operators.coreos.com/v1alpha1 kind: CatalogSource metadata: name: operatorhubio-catalog namespace: openshift-marketplace 1 spec: sourceType: grpc image: quay.io/operatorhubio/catalog:latest displayName: Community Operators 2 publisher: OperatorHub.io grpcPodConfig: securityContextConfig: restricted 3 updateStrategy: registryPoll: interval: 60m
- 1
- The global namespace. Setting the
metadata.namespace
toopenshift-marketplace
enables the catalog to run in all namespaces. Subscriptions CRs in any namespace can reference catalogs created in theopenshift-marketplace
namespace. - 2
- Community Operators are not installed by default with OLM for MicroShift. Listed here for example only.
- 3
- The value of
securityContextConfig
must be set torestricted
for MicroShift.
Apply the
CatalogSource
configuration by running the following command:$ oc apply -f <catalog_source.yaml> 1
- 1
- Replace
<catalog_source.yaml>
with your catalog source configuration file name.
To verify that the catalog source is applied, check for the
READY
state by using the following command:$ oc describe catalogsources.operators.coreos.com -n openshift-marketplace operatorhubio-catalog
Example output
Name: operatorhubio-catalog Namespace: openshift-marketplace Labels: <none> Annotations: <none> API Version: operators.coreos.com/v1alpha1 Kind: CatalogSource Metadata: Creation Timestamp: 2024-01-31T10:09:46Z Generation: 1 Resource Version: 2811 UID: 60ce4a36-86d3-4921-b9fc-84d67c28df48 Spec: Display Name: Community Operators Grpc Pod Config: Security Context Config: restricted Image: quay.io/operatorhubio/catalog:latest Publisher: OperatorHub.io Source Type: grpc Update Strategy: Registry Poll: Interval: 60m Status: Connection State: Address: operatorhubio-catalog.openshift-marketplace.svc:50051 Last Connect: 2024-01-31T10:10:04Z Last Observed State: READY 1 Registry Service: Created At: 2024-01-31T10:09:46Z Port: 50051 Protocol: grpc Service Name: operatorhubio-catalog Service Namespace: openshift-marketplace Events: <none>
- 1
- The status is reported as
READY
.
Confirm that the catalog source is running by using the following command:
$ oc get pods -n openshift-marketplace -l olm.catalogSource=operatorhubio-catalog
Example output
NAME READY STATUS RESTARTS AGE operatorhubio-catalog-j7sc8 1/1 Running 0 43s
Create a Subscription CR configuration file by using the following example YAML:
Example Subscription custom resource YAML
apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: my-gitlab-operator-kubernetes namespace: olm-microshift 1 spec: channel: stable name: gitlab-operator-kubernetes source: operatorhubio-catalog sourceNamespace: openshift-marketplace 2
Apply the Subscription CR configuration by running the following command:
$ oc apply -f <subscription_cr.yaml> 1
- 1
- Replace
<subscription_cr.yaml>
with the name of the Subscription CR configuration file.
Example output
subscription.operators.coreos.com/my-gitlab-operator-kubernetes
- You can create a configuration file for the specific Operand you want to use and apply it now.
Verification
Verify that your Operator is running by using the following command:
$ oc get pods -n olm-microshift 1
- 1
- The namespace from the Subscription CR is used.
NoteAllow a minute or two for the Operator start.
Example output
NAME READY STATUS RESTARTS AGE gitlab-controller-manager-69bb6df7d6-g7ntx 2/2 Running 0 3m24s
Additional resources
8.3. Creating custom catalogs using the oc-mirror plugin
You can create custom catalogs with widely available Operators and mirror them by using the oc-mirror OpenShift CLI (oc) plugin.
8.3.1. Using Red Hat-provided Operator catalogs and mirror registries
You can filter and prune catalogs to get specific Operators and mirror them by using the oc-mirror OpenShift CLI (oc) plugin. You can also use Operators in disconnected settings or embedded in Red Hat Enterprise Linux for Edge (RHEL for Edge) images. To read more details about how to configure your systems for mirroring, use the links in the following "Additional resources" section. If you are ready to deploy Operators from Red Hat-provided Operator catalogs, mirror them, or to embed them in RHEL for Edge images, start with the following section, "Inspecting catalog contents by using the oc-mirror plugin."
8.3.2. About the oc-mirror plugin for creating a mirror registry
You can use the oc-mirror OpenShift CLI (oc) plugin with MicroShift to filter and prune Operator catalogs. You can then mirror the filtered catalog contents to a mirror registry or use the container images in disconnected or offline deployments with RHEL for Edge.
MicroShift uses the generally available version (1) of the oc-mirror plugin. Do not use the following procedures with the Technical Preview version (2) of oc-mirror plugin.
You can mirror the container images required by the desired Operators locally or to a container mirror registry that supports Docker v2-2, such as Red Hat Quay. The procedure to mirror content from Red Hat-hosted registries connected to the internet to a disconnected image registry is the same, independent of the registry you choose. After you mirror the contents of your catalog, configure each cluster to retrieve this content from your mirror registry.
8.3.2.1. Connectivity considerations when populating a mirror registry
When you populate your registry, you can use one of following connectivity scenarios:
- Connected mirroring
- If you have a host that can access both the internet and your mirror registry, but not your cluster node, you can directly mirror the content from that machine.
- Disconnected mirroring
If you do not have a host that can access both the internet and your mirror registry, you must mirror the images to a file system and then bring that host or removable media into your disconnected environment.
ImportantA container registry must be reachable by every machine in the clusters that you provision. Installing, updating, and other operations, such as relocating workloads, might fail if the registry is unreachable.
To avoid problems caused by an unreachable registry, use the following standard practices:
- Run mirror registries in a highly available way.
- Ensure that the mirror registry at least matches the production availability of your clusters.
Additional resources
8.3.2.2. Inspecting catalog contents by using the oc-mirror plugin
Use the following example procedure to select a catalog and list Operators from available OpenShift Container Platform content to add to your oc-mirror plugin image set configuration file.
If you use your own catalogs and Operators, you can push the images directly to your internal registry.
Prerequisites
-
The OpenShift CLI (
oc
) is installed. - Operator Lifecycle Manager (OLM) is installed.
- The oc-mirror OpenShift CLI (oc) plugin is installed.
Procedure
Get a list of available Red Hat-provided Operator catalogs to filter by running the following command:
$ oc mirror list operators --version 4.17 --catalogs
Get a list of Operators in the Red Hat Operators catalog by running the following command:
$ oc mirror list operators <--catalog=<catalog_source>> 1
- 1
- Specifies your catalog source, such as
registry.redhat.io/redhat/redhat-operator-index:v4.17
orquay.io/operatorhubio/catalog:latest
.
-
Select an Operator. For this example,
amq-broker-rhel8
is selected. Optional: To inspect the channels and versions of the Operator you want to filter, enter the following commands:
Get a list of channels by running the following command:
$ oc mirror list operators --catalog=registry.redhat.io/redhat/redhat-operator-index:v4.17 --package=amq-broker-rhel8
Get a list of versions within a channel by running the following command:
$ oc mirror list operators --catalog=registry.redhat.io/redhat/redhat-operator-index:v4.17 --package=amq-broker-rhel8 --channel=7.11.x
Next steps
- Create and edit an image set configuration file using the information gathered in this procedure.
- Mirror the images from the transformed image set configuration file to a mirror registry or disk.
8.3.2.3. Creating an image set configuration file
You must create an image set configuration file to mirror catalog contents with the oc-mirror plugin. The image set configuration file defines which Operators to mirror along with other configuration settings for the oc-mirror plugin. After generating a default image set file, you must edit the contents so that remaining entries are compatible with both MicroShift and the Operator you plan to use.
You must specify a storage backend in the image set configuration file. This storage backend can be a local directory or a registry that supports Docker v2-2. The oc-mirror plugin stores metadata in this storage backend during image set creation.
Do not delete or modify the metadata that is generated by the oc-mirror plugin. You must use the same storage backend every time you run the oc-mirror plugin for the same mirror registry.
Prerequisites
- You have created a container image registry credentials file. See Configuring credentials that allow images to be mirrored.
Procedure
Use the
oc mirror init
command to create a template for the image set configuration and save it to a file calledimageset-config.yaml
:$ oc mirror init <--registry <storage_backend> > imageset-config.yaml 1
- 1
- Specifies the location of your storage backend, such as
example.com/mirror/oc-mirror-metadata
.
Example default image set configuration file
kind: ImageSetConfiguration apiVersion: mirror.openshift.io/v1alpha2 storageConfig: registry: imageURL: registry.example.com/oc-mirror skipTLS: false mirror: platform: 1 channels: - name: stable-4.17 type: ocp operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.17 packages: - name: serverless-operator channels: - name: stable additionalImages: 2 - name: registry.redhat.io/ubi8/ubi:latest helm: {} 3
Edit the values of your image set configuration file to meet the requirements of both MicroShift and the Operator you want to mirror, like the following example:
Example edited MicroShift image set configuration file
kind: ImageSetConfiguration apiVersion: mirror.openshift.io/v1alpha2 storageConfig: 1 registry: imageURL: <storage_backend> 2 skipTLS: false mirror: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.17 3 packages: - name: amq-broker-rhel8 4 channels: - name: 7.11.x 5
- 1
- Set the backend location where the image set metadata is saved. This location can be a registry or local directory. It is required to specify
storageConfig
values. - 2
- Set the registry URL for the storage backend, such as
<example.com/mirror/oc-mirror-metadata
. - 3
- Set the Operator catalog to retrieve images from.
- 4
- Specify the Operator packages to include in the image set. Remove this field to retrieve all packages in the catalog.
- 5
- Specify only certain channels of the Operator packages to include in the image set. You must always include the default channel for the Operator package even if you do not use the bundles in that channel. You can find the default channel by running the following command:
oc mirror list operators --catalog=<catalog_name> --package=<package_name>
.
- Save the updated file.
Next steps
- Use the oc-mirror plugin to mirror an image set directly to a target mirror registry.
- Configure CRI-O.
- Apply the catalog sources to your clusters.
8.3.2.3.1. Image set configuration parameters
The oc-mirror plugin requires an image set configuration file that defines what images to mirror. The following table lists the available parameters for the ImageSetConfiguration
resource.
Parameter | Description | Values |
---|---|---|
|
The API version for the |
String. For example: |
| The configuration of the image set. | Object |
| The additional images configuration of the image set. | Array of objects. For example: additionalImages: - name: registry.redhat.io/ubi8/ubi:latest |
| The tag or digest of the image to mirror. |
String. For example: |
| The full tag, digest, or pattern of images to block from mirroring. |
Array of strings. For example: |
| The Operators configuration of the image set. | Array of objects. For example: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.17 packages: - name: elasticsearch-operator minVersion: '2.4.0' |
| The Operator catalog to include in the image set. |
String. For example: |
|
When |
Boolean. The default value is |
| The Operator packages configuration. | Array of objects. For example: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.17 packages: - name: elasticsearch-operator minVersion: '5.2.3-31' |
| The Operator package name to include in the image set |
String. For example: |
| The Operator package channel configuration. | Object |
| The Operator channel name, unique within a package, to include in the image set. |
String. For example: |
| The highest version of the Operator mirror across all channels in which it exists. See the following note for further information. |
String. For example: |
| The name of the minimum bundle to include, plus all bundles in the update graph to the channel head. Set this field only if the named bundle has no semantic version metadata. |
String. For example: |
| The lowest version of the Operator to mirror across all channels in which it exists. See the following note for further information. |
String. For example: |
| The highest version of the Operator to mirror across all channels in which it exists. See the following note for further information. |
String. For example: |
| The lowest version of the Operator to mirror across all channels in which it exists. See the following note for further information. |
String. For example: |
|
If |
Boolean. The default value is |
| An alternative name and optional namespace hierarchy to mirror the referenced catalog as. |
String. For example: |
| An alternative name to mirror the referenced catalog as.
The |
String. For example: |
|
An alternative tag to append to the |
String. For example: |
| The back-end configuration of the image set. | Object |
| The local back-end configuration of the image set. | Object |
| The path of the directory to contain the image set metadata. |
String. For example: |
| The registry back-end configuration of the image set. | Object |
| The back-end registry URI. Can optionally include a namespace reference in the URI. |
String. For example: |
| Optionally skip TLS verification of the referenced back-end registry. |
Boolean. The default value is |
Using the minVersion
and maxVersion
properties to filter for a specific Operator version range can result in a multiple channel heads error. The error message states that there are multiple channel heads
. This is because when the filter is applied, the update graph of the Operator is truncated.
Operator Lifecycle Manager requires that every Operator channel contains versions that form an update graph with exactly one end point, that is, the latest version of the Operator. When the filter range is applied, that graph can turn into two or more separate graphs or a graph that has more than one end point.
To avoid this error, do not filter out the latest version of an Operator. If you still run into the error, depending on the Operator, either the maxVersion
property must be increased or the minVersion
property must be decreased. Because every Operator graph can be different, you might need to adjust these values until the error resolves.
Additional resources
8.3.2.4. Mirroring from mirror to mirror
You can use the oc-mirror plugin to mirror an image set directly to a target mirror registry that is accessible during image set creation.
You are required to specify a storage backend in the image set configuration file. This storage backend can be a local directory or a Docker v2 registry. The oc-mirror plugin stores metadata in this storage backend during image set creation.
Do not delete or modify the metadata that is generated by the oc-mirror plugin. You must use the same storage backend every time you run the oc-mirror plugin for the same mirror registry.
Prerequisites
- You have access to the internet to get the necessary container images.
-
You have installed the OpenShift CLI (
oc
). -
You have installed the
oc-mirror
CLI plugin. - You have created the image set configuration file.
Procedure
Run the
oc mirror
command to mirror the images from the specified image set configuration to a specified registry:$ oc mirror --config=./<imageset-config.yaml> \1 docker://registry.example:5000 2
- 1
- Specify the image set configuration file that you created. For example,
imageset-config.yaml
. - 2
- Specify the registry to mirror the image set file to. The registry must start with
docker://
. If you specify a top-level namespace for the mirror registry, you must also use this same namespace on subsequent executions.
Example output
Rendering catalog image "registry.example.com/redhat/redhat-operator-index:v{ocp-version}" with file-based catalog
Verification
-
Navigate into the
oc-mirror-workspace/
directory that was generated. -
Navigate into the results directory, for example,
results-1639608409/
. -
Verify that YAML files are present for the
ImageContentSourcePolicy
andCatalogSource
resources.
The ImageContentSourcePolicy
YAML file is used as reference content for manual configuration of CRI-O in MicroShift. You cannot apply the resource directly into a MicroShift cluster.
Next steps
-
Convert the
ImageContentSourcePolicy
YAML content for use in manually configuring CRI-O. - If required, mirror the images from mirror to disk for disconnected or offline use.
- Configure your cluster to use the resources generated by oc-mirror.
Troubleshooting
8.3.2.5. Configuring CRI-O for using a registry mirror for Operators
You must transform the imageContentSourcePolicy.yaml
file created with the oc-mirror plugin into a format that is compatible with the CRI-O container runtime configuration used by MicroShift.
Prerequisites
-
The OpenShift CLI (
oc
) is installed. - Operator Lifecycle Manager (OLM) is installed.
- The oc-mirror OpenShift CLI (oc) plugin is installed.
-
The
yq
binary is installed. -
ImageContentSourcePolicy
andCatalogSource
YAML files are available in theoc-mirror-workspace/results-*
directory.
Procedure
Confirm the contents of the
imageContentSourcePolicy.yaml
file by running the following command:$ cat oc-mirror-workspace/<results-directory>/imageContentSourcePolicy.yaml 1
- 1
- Specify the
results
directory name, such as<results-1707148826>
.
Example output
apiVersion: operator.openshift.io/v1alpha1 kind: ImageContentSourcePolicy metadata: labels: operators.openshift.org/catalog: "true" name: operator-0 spec: repositoryDigestMirrors: - mirrors: - registry.<example.com>/amq7 source: registry.redhat.io/amq7
Transform the
imageContentSourcePolicy.yaml
into a format ready for CRI-O configuration by running the following command:yq '.spec.repositoryDigestMirrors[] as $item ireduce([]; . + [{"mirror": $item.mirrors[], "source": ($item | .source)}]) | .[] | "[[registry]] prefix = \"" + .source + "\" location = \"" + .mirror + "\" mirror-by-digest-only = true insecure = true "' ./icsp.yaml
Example output
[[registry]] prefix = "registry.redhat.io/amq7" location = "registry.example.com/amq7" mirror-by-digest-only = true insecure = true
Add the output to the CRI-O configuration file in the
/etc/containers/registries.conf.d/
directory:Example
crio-config.yaml
mirror configuration file[[registry]] prefix = "registry.redhat.io/amq7" location = "registry.example.com/amq7" mirror-by-digest-only = true insecure = true [[registry]] prefix = "" location = "quay.io" mirror-by-digest-only = true [[registry.mirror]] location = "<registry_host>:<port>" 1 insecure = false
- 1
- Specify the host name and port of your mirror registry server, for example
microshift-quay:8443
.
Apply the CRI-O configuration changes by restarting MicroShift with the following command:
$ sudo systemctl restart crio
8.3.2.6. Installing a custom catalog created with the oc-mirror plugin
After you mirror your image set to the mirror registry, you must apply the generated CatalogSource
custom resource (CR) into the cluster. The CatalogSource
CR is used by Operator Lifecycle Manager (OLM) to retrieve information about the available Operators in the mirror registry. You must then create and apply a subscription CR to subscribe to your custom catalog.
Prerequisites
- You mirrored the image set to your registry mirror.
- You added image reference information to the CRI-O container runtime configuration.
Procedure
Apply the catalog source configuration file from the results directory to create the catalog source object by running the following command:
$ oc apply -f ./oc-mirror-workspace/results-1708508014/catalogSource-cs-redhat-operator-index.yaml
Example catalog source configuration file
apiVersion: operators.coreos.com/v1alpha1 kind: CatalogSource metadata: name: redhat-catalog namespace: openshift-marketplace 1 spec: sourceType: grpc image: registry.example.com/redhat/redhat-operator-index:v4.17 updateStrategy: registryPoll: interval: 60m
- 1
- Specifies the global namespace. Setting the
metadata.namespace
toopenshift-marketplace
enables the catalog to reference catalogs in all namespaces. Subscriptions in any namespace can reference catalogs created in theopenshift-marketplace
namespace.
Example output
catalogsource.operators.coreos.com/cs-redhat-operator-index created
Verify that the
CatalogSource
resources were successfully installed by running the following command:$ oc get catalogsource --all-namespaces
Verify that the catalog source is running by using the following command:
$ oc get pods -n openshift-marketplace
Example output
NAME READY STATUS RESTARTS AGE cs-redhat-operator-index-4227b 2/2 Running 0 2m5s
Create a
Subscription
CR, similar to the following example:Example
Subscription
CRapiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: amq-broker namespace: openshift-operators spec: channel: 7.11.x name: amq-broker-rhel8 source: cs-redhat-operator-index sourceNamespace: openshift-marketplace
Apply the Subscription CR configuration by running the following command:
$ oc apply -f ./<my-subscription-cr.yaml> 1
- 1
- Specify the name of your subscription, such as
my-subscription-cr.yaml
.
Example output
subscription.operators.coreos.com/amq-broker created
8.4. Adding OLM-based Operators to a disconnected cluster
You can use OLM-based Operators in disconnected situations by embedding them in a Red Hat Enterprise Linux for Edge (RHEL for Edge) image.
8.4.1. About adding OLM-based Operators to a disconnected cluster
For Operators that are installed on disconnected clusters, Operator Lifecycle Manager (OLM) by default cannot access sources hosted on remote registries because those remote sources require full internet connectivity. Therefore, you must mirror the remote registries to a highly available container registry.
The following steps are required to use OLM-based Operators in disconnected situations:
- Include OLM in the container image list for your mirror registry.
-
Configure the system to use your mirror registry by updating your CRI-O configuration directly.
ImageContentSourcePolicy
is not supported in MicroShift. -
Add a
CatalogSource
object to the cluster so that the OLM catalog Operator can use the local catalog on the mirror registry. - Ensure that MicroShift is installed to run in a disconnected capacity.
- Ensure that the network settings are configured to run in disconnected mode.
After enabling OLM in a disconnected cluster, you can continue to use your internet-connected workstation to keep your local catalog sources updated as newer versions of Operators are released.
Additional resources
8.4.1.1. Performing a dry run
You can use oc-mirror to perform a dry run, without actually mirroring any images. This allows you to review the list of images that would be mirrored, as well as any images that would be pruned from the mirror registry. A dry run also allows you to catch any errors with your image set configuration early or use the generated list of images with other tools to carry out the mirroring operation.
Prerequisites
- You have access to the internet to obtain the necessary container images.
-
You have installed the OpenShift CLI (
oc
). -
You have installed the
oc-mirror
CLI plugin. - You have created the image set configuration file.
Procedure
Run the
oc mirror
command with the--dry-run
flag to perform a dry run:$ oc mirror --config=./imageset-config.yaml \1 docker://registry.example:5000 \2 --dry-run 3
- 1
- Pass in the image set configuration file that was created. This procedure assumes that it is named
imageset-config.yaml
. - 2
- Specify the mirror registry. Nothing is mirrored to this registry as long as you use the
--dry-run
flag. - 3
- Use the
--dry-run
flag to generate the dry run artifacts and not an actual image set file.
Example output
Checking push permissions for registry.example:5000 Creating directory: oc-mirror-workspace/src/publish Creating directory: oc-mirror-workspace/src/v2 Creating directory: oc-mirror-workspace/src/charts Creating directory: oc-mirror-workspace/src/release-signatures No metadata detected, creating new workspace wrote mirroring manifests to oc-mirror-workspace/operators.1658342351/manifests-redhat-operator-index ... info: Planning completed in 31.48s info: Dry run complete Writing image mapping to oc-mirror-workspace/mapping.txt
Navigate into the workspace directory that was generated:
$ cd oc-mirror-workspace/
Review the
mapping.txt
file that was generated.This file contains a list of all images that would be mirrored.
Review the
pruning-plan.json
file that was generated.This file contains a list of all images that would be pruned from the mirror registry when the image set is published.
NoteThe
pruning-plan.json
file is only generated if your oc-mirror command points to your mirror registry and there are images to be pruned.
8.4.1.2. Getting catalogs and Operator container image references to use with RHEL for Edge in disconnected environments
After performing a dry run with the oc-mirror plugin to review the list of images that you want to mirror, you must get all of the container image references, then format the output for adding to an Image Builder blueprint.
For catalogs made for proprietary Operators, you can format image references for the Image Builder blueprint without using the following procedure.
Prerequisites
- You have a catalog index for the Operators you want to use.
-
You have installed the
jq
CLI tool. - You are familiar with Image Builder blueprint files.
- You have an Image Builder blueprint TOML file.
Procedure
Parse the catalog
index.json
file to get the image references that you need to include in the Image Builder blueprint. You can use either the unfiltered catalog or you can filter out images that cannot be mirrored:Parse the unfiltered catalog
index.json
file to get the image references by running the following command:jq -r --slurp '.[] | select(.relatedImages != null) | "[[containers]]\nsource = \"" + .relatedImages[].image + "\"\n"' ./oc-mirror-workspace/src/catalogs/registry.redhat.io/redhat/redhat-operator-index/v4.17/index/index.json
If you want to filter out images that cannot be mirrored, filter and parse the catalog
index.json
file by running the following command:$ jq -r --slurp '.[] | select(.relatedImages != null) | .relatedImages[] | select(.name | contains("ppc") or contains("s390x") | not) | "[[containers]]\\nsource = \\"" + .image + "\\"\\n"' ./oc-mirror-workspace/src/catalogs/registry.redhat.io/redhat/redhat-operator-index/v4.17/index/index.json
NoteThis step uses the AMQ Broker Operator as an example. You can add other criteria to the
jq
command for further filtering as required by your use case.Example image-reference output
[[containers]] source = "registry.redhat.io/amq7/amq-broker-init-rhel8@sha256:0b2126cfb6054fdf428c1f43b69e36e93a09a49ce15350e9273c98cc08c6598b" [[containers]] source = "registry.redhat.io/amq7/amq-broker-init-rhel8@sha256:0dde839c2dce7cb684094bf26523c8e16677de03149a0fff468b8c3f106e1f4f" ... ... [[containers]] source = "registry.redhat.io/amq7/amq-broker-rhel8@sha256:e8fa2a00e576ecb95561ffbdbf87b1c82d479c8791ab2c6ce741dd0d0b496d15" [[containers]] source = "registry.redhat.io/amq7/amq-broker-rhel8@sha256:ff6fefad518a6c997d4c5a6e475ba89640260167f0bc27715daf3cc30116fad1" … EOF
ImportantFor mirrored and disconnected use cases, ensure that all of the sources filtered from your catalog
index.json
file are digests. If any of the sources use tags instead of digests, the Operator installation fails. Tags require an internet connection.
View the
imageset-config.yaml
to get the catalog image reference for theCatalogSource
custom resource (CR) by running the following command:$ cat imageset-config.yaml
Example output
kind: ImageSetConfiguration apiVersion: mirror.openshift.io/v1alpha2 storageConfig: registry: imageURL: registry.example.com/microshift-mirror mirror: operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.17 1 packages: - name: amq-broker-rhel8 channels: - name: 7.11.x
- 1
- Use the value in the
mirror.catalog
catalog image reference for the follwingjq
command to get the image digest. In this example, <registry.redhat.io/redhat/redhat-operator-index:v4.17>.
Get the SHA of the catalog index image by running the following command:
$ skopeo inspect docker://<registry.redhat.io/redhat/redhat-operator-index:v4.17> | jq `.Digest` 1
- 1
- Use the value in the
mirror.catalog
catalog image reference for thejq
command to get the image digest. In this example, <registry.redhat.io/redhat/redhat-operator-index:v4.17>.
Example output
"sha256:7a76c0880a839035eb6e896d54ebd63668bb37b82040692141ba39ab4c539bc6"
To get ready to add the image references to your Image Builder blueprint file, format the catalog image reference by using the following example:
[[containers]] source = "registry.redhat.io/redhat/redhat-operator-index@sha256:7a76c0880a839035eb6e896d54ebd63668bb37b82040692141ba39ab4c539bc6"
Add the image references from all the previous steps to the Image Builder blueprint.
Generated Image Builder blueprint example snippet
name = "microshift_blueprint" description = "MicroShift 4.17.1 on x86_64 platform" version = "0.0.1" modules = [] groups = [] [[packages]] 1 name = "microshift" version = "4.17.1" ... ... [customizations.services] 2 enabled = ["microshift"] [customizations.firewall] ports = ["22:tcp", "80:tcp", "443:tcp", "5353:udp", "6443:tcp", "30000-32767:tcp", "30000-32767:udp"] ... ... [[containers]] 3 source = "quay.io/openshift-release-dev/ocp-v4.0-art-dev@sha256:f41e79c17e8b41f1b0a5a32c3e2dd7cd15b8274554d3f1ba12b2598a347475f4" [[containers]] source = "quay.io/openshift-release-dev/ocp-v4.0-art-dev@sha256:dbc65f1fba7d92b36cf7514cd130fe83a9bd211005ddb23a8dc479e0eea645fd" ... ... [[containers]] 4 source = "registry.redhat.io/redhat/redhat-operator-index@sha256:7a76c0880a839035eb6e896d54ebd63668bb37b82040692141ba39ab4c539bc6" ... ... [[containers]] source = "registry.redhat.io/amq7/amq-broker-init-rhel8@sha256:0dde839c2dce7cb684094bf26523c8e16677de03149a0fff468b8c3f106e1f4f" ... ... [[containers]] source = "registry.redhat.io/amq7/amq-broker-rhel8@sha256:e8fa2a00e576ecb95561ffbdbf87b1c82d479c8791ab2c6ce741dd0d0b496d15" [[containers]] source = "registry.redhat.io/amq7/amq-broker-rhel8@sha256:ff6fefad518a6c997d4c5a6e475ba89640260167f0bc27715daf3cc30116fad1" … EOF
- 1
- References for all non-optional MicroShift RPM packages using the same version compatible with the
microshift-release-info
RPM. - 2
- References for automatically enabling MicroShift on system startup and applying default networking settings.
- 3
- References for all non-optional MicroShift container images necessary for a disconnected deployment.
- 4
- References for the catalog index.
8.4.1.3. Applying catalogs and Operators in a disconnected-deployment RHEL for Edge image
After you have created a RHEL for Edge image for a disconnected environment and configured MicroShift networking settings for disconnected use, you can configure the namespace and create catalog and Operator custom resources (CR) for running your Operators.
Prerequisites
- You have a RHEL for Edge image.
- Networking is configured for disconnected use.
- You completed the oc-mirror plugin dry run procedure.
Procedure
Create a
CatalogSource
custom resource (CR), similar to the following example:Example
my-catalog-source-cr.yaml
fileapiVersion: operators.coreos.com/v1alpha1 kind: CatalogSource metadata: name: cs-redhat-operator-index namespace: openshift-marketplace 1 spec: image: registry.example.com/redhat/redhat-operator-index:v4.17 sourceType: grpc displayName: publisher: updateStrategy: registryPoll: interval: 60m
- 1
- The global namespace. Setting the
metadata.namespace
toopenshift-marketplace
enables the catalog to run in all namespaces. Subscriptions in any namespace can reference catalogs created in theopenshift-marketplace
namespace.
NoteThe default pod security admission definition for
openshift-marketplace
isbaseline
, therefore a catalog source custom resource (CR) created in that namespace does not require aspec.grpcPodConfig.securityContextConfig
value to be set. You can set alegacy
orrestricted
value if required for the namespace and Operators you want to use.Add the SHA of the catalog index commit to the Catalog Source (CR), similar to the following example:
Example namespace
spec.image
configurationapiVersion: operators.coreos.com/v1alpha1 kind: CatalogSource metadata: name: cs-redhat-operator-index namespace: openshift-marketplace spec: image: registry.example.com/redhat/redhat-operator-index@sha256:7a76c0880a839035eb6e896d54ebd63668bb37b82040692141ba39ab4c539bc6 1 sourceType: grpc displayName: publisher: updateStrategy: registryPoll: interval: 60m
- 1
- The SHA of the image commit. Use the same SHA you added to the image builder blueprint.
ImportantYou must use the SHA instead of a tag in your catalog CR or the pod fails to start.
Apply the YAML file from the oc-mirror plugin dry run results directory to the cluster by running the following command:
$ oc apply -f ./oc-mirror-workspace/results-1708508014/catalogSource-cs-redhat-operator-index.yaml
Example output
catalogsource.operators.coreos.com/cs-redhat-operator-index created
Verify that the
CatalogSource
resources were successfully installed by running the following command:$ oc get catalogsource --all-namespaces
Verify that the catalog source is running by using the following command:
$ oc get pods -n openshift-marketplace
Example output
NAME READY STATUS RESTARTS AGE cs-redhat-operator-index-4227b 2/2 Running 0 2m5s
Create a
Subscription
CR, similar to the following example:Example
my-subscription-cr.yaml
fileapiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: amq-broker namespace: openshift-operators spec: channel: 7.11.x name: amq-broker-rhel8 source: cs-redhat-operator-index sourceNamespace: openshift-marketplace
Apply the
Subscription
CR by running the following command:$ oc apply -f ./<my-subscription-cr.yaml> 1
- 1
- Specify the name of your
Subscription
CR, such asmy-subscription-cr.yaml
.
Example output
subscription.operators.coreos.com/amq-broker created