Chapter 5. Master and Node Configuration

5.1. Overview

The openshift start command is used to launch OpenShift Container Platform servers. The command and its subcommands (master to launch a master server and node to launch a node server) all take a limited set of arguments that are sufficient for launching servers in a development or experimental environment.

However, these arguments are insufficient to describe and control the full set of configuration and security options that are necessary in a production environment. To provide those options, it is necessary to use the dedicated master and node configuration files.

Master configuration files and node configuration files are fully specified with no default values. Therefore, any empty value indicates that you want to start up with an empty value for that parameter. This makes it easy to reason about exactly what your configuration is, but it also makes it difficult to remember all of the options to specify. To make this easier, the configuration files can be created with the --write-config option and then used with the --config option.

5.2. Master Configuration Files

This section reviews parameters mentioned in the master-config.yaml file.

You can create a new master configuration file to see the valid options for your installed version of OpenShift Container Platform.

Important

Whenever you modify the master-config.yaml file, you must restart the master for the changes to take effect. See Restarting OpenShift Container Platform services.

5.2.1. Admission Control Configuration

Table 5.1. Admission Control Configuration Parameters
Parameter Name	Description
`AdmissionConfig`	Contains admission control plug-in configuration.
`APIServerArguments`	Key-value pairs that will be passed directly to the Kube API server that match the API servers' command line arguments. These are not migrated, but if you reference a value that does not exist the server will not start. These values may override other settings in `KubernetesMasterConfig`, which may cause invalid configurations.
`ControllerArguments`	Key-value pairs that will be passed directly to the Kube controller manager that match the controller manager’s command line arguments. These are not migrated, but if you reference a value that does not exist the server will not start. These values may override other settings in `KubernetesMasterConfig`, which may cause invalid configurations.
`DefaultAdmissionConfig`	Used to enable or disable various admission plug-ins. When this type is present as the configuration object under `pluginConfig` and if the admission plug-in supports it, this will cause an off by default admission plug-in to be enabled.
`PluginConfig`	Allows specifying a configuration file per admission control plug-in.
`PluginOrderOverride`	A list of admission control plug-in names that will be installed on the master. Order is significant. If empty, a default list of plug-ins is used.
`SchedulerArguments`	Key-value pairs that will be passed directly to the Kube scheduler that match the scheduler’s command line arguments. These are not migrated, but if you reference a value that does not exist the server will not start. These values may override other settings in `KubernetesMasterConfig`, which may cause invalid configurations.

5.2.2. Asset Configuration

Table 5.2. Asset Configuration Parameters
Parameter Name	Description
`AssetConfig`	Holds the necessary configuration options for serving assets.
`corsAllowedOrigins`	To access the API server from a web application using a different host name, you must whitelist that host name by specifying `corsAllowedOrigins` in the configuration field or by specifying the `--cors-allowed-origins` option on `openshift start`. No pinning or escaping is done to the value. See Web Console for example usage.
`DisabledFeatures`	A list of features that should not be started. You will likely want to set this as null. It is very unlikely that anyone will want to manually disable features and that is not encouraged.
`Extensions`	Files to serve from the asset server file system under a subcontext.
`ExtensionDevelopment`	When set to true, tells the asset server to reload extension scripts and stylesheets for every request rather than only at startup. It lets you develop extensions without having to restart the server for every change.
`ExtensionProperties`	Key- (string) and value- (string) pairs that will be injected into the console under the global variable `OPENSHIFT_EXTENSION_PROPERTIES`.
`ExtensionScripts`	File paths on the asset server files to load as scripts when the web console loads.
`ExtensionStylesheets`	File paths on the asset server files to load as style sheets when the web console loads.
`LoggingPublicURL`	The public endpoint for logging (optional).
`LogoutURL`	An optional, absolute URL to redirect web browsers to after logging out of the web console. If not specified, the built-in logout page is shown.
`MasterPublicURL`	How the web console can access the OpenShift Container Platform server.
`MetricsPublicURL`	The public endpoint for metrics (optional).
`PublicURL`	URL of the the asset server.

5.2.3. Authentication and Authorization Configuration

Table 5.3. Authentication and Authorization Parameters
Parameter Name	Description
`authConfig`	Holds authentication and authorization configuration options.
`AuthenticationCacheSize`	Indicates how many authentication results should be cached. If 0, the default cache size is used.
`AuthorizationCacheTTL`	Indicates how long an authorization result should be cached. It takes a valid time duration string (e.g. "5m"). If empty, you get the default timeout. If zero (e.g. "0m"), caching is disabled.

5.2.4. Controller Configuration

Table 5.4. Controller Configuration Parameters
Parameter Name	Description
`Controllers`	List of the controllers that should be started. If set to none, no controllers will start automatically. The default value is * which will start all controllers. When using *, you may exclude controllers by prepending a `-` in front of their name. No other values are recognized at this time.
`ControllerLeaseTTL`	Enables controller election, instructing the master to attempt to acquire a lease before controllers start and renewing it within a number of seconds defined by this value. Setting this value non-negative forces `pauseControllers=true`. This value defaults off (0, or omitted) and controller election can be disabled with -1.
`PauseControllers`	Instructs the master to not automatically start controllers, but instead to wait until a notification to the server is received before launching them.

5.2.5. etcd Configuration

Table 5.5. etcd Configuration Parameters
Parameter Name	Description
`Address`	The advertised host:port for client connections to etcd.
`etcdClientInfo`	Contains information about how to connect to etcd.
`etcdConfig`	Holds the necessary configuration options for connecting with an etcd database.
`etcdStorageConfig`	Contains information about how API resources are stored in etcd. These values are only relevant when etcd is the backing store for the cluster.
`KubernetesStoragePrefix`	The path within etcd that the Kubernetes resources will be rooted under. This value, if changed, will mean existing objects in *etcd* will no longer be located. The default value is kubernetes.io.
`KubernetesStorageVersion`	The API version that Kubernetes resources in *etcd* should be serialized to. This value should not be advanced until all clients in the cluster that read from etcd have code that allows them to read the new version.
`OpenShiftStoragePrefix`	The path within etcd that the OpenShift Container Platform resources will be rooted under. This value, if changed, will mean existing objects in etcd will no longer be located. The default value is openshift.io.
`OpenShiftStorageVersion`	API version that OS resources in *etcd* should be serialized to. This value should not be advanced until all clients in the cluster that read from *etcd* have code that allows them to read the new version.
`PeerAddress`	The advertised host:port for peer connections to *etcd*.
`PeerServingInfo`	Describes how to start serving the *etcd* peer.
`ServingInfo`	Describes how to start serving the etcd master.
`StorageDir`	The path to the *etcd* storage directory.

5.2.6. Grant Configuration

Table 5.6. Grant Configuration Parameters
Parameter Name	Description
`GrantConfig`	Describes how to handle grants.
`GrantHandlerAuto`	Auto-approves client authorization grant requests.
`GrantHandlerDeny`	Auto-denies client authorization grant requests.
`GrantHandlerPrompt`	Prompts the user to approve new client authorization grant requests.
`Method`	Determines the default strategy to use when an OAuth client requests a grant.This method will be used only if the specific OAuth client does not provide a strategy of their own. Valid grant handling methods are: auto: always approves grant requests, useful for trusted clients prompt: prompts the end user for approval of grant requests, useful for third-party clients deny: always denies grant requests, useful for black-listed clients

5.2.7. Image Configuration

Table 5.7. Image Configuration Parameters
Parameter Name	Description
`Format`	The format of the name to be built for the system component.
`Latest`	Determines if the latest tag will be pulled from the registry.

5.2.8. Image Policy Configuration

Table 5.8. Image Policy Configuration Parameters
Parameter Name	Description
`DisableScheduledImport`	Allows scheduled background import of images to be disabled.
`MaxImagesBulkImportedPerRepository`	Controls the number of images that are imported when a user does a bulk import of a Docker repository. This number defaults to 5 to prevent users from importing large numbers of images accidentally. Set -1 for no limit.
`MaxScheduledImageImportsPerMinute`	The maximum number of scheduled image streams that will be imported in the background per minute. The default value is 60.
`ScheduledImageImportMinimumIntervalSeconds`	The minimum number of seconds that can elapse between when image streams scheduled for background import are checked against the upstream repository. The default value is 15 minutes.
`AllowedRegistriesForImport`	Limits the docker registries that normal users may import images from. Set this list to the registries that you trust to contain valid Docker images and that you want applications to be able to import from. Users with permission to create Images or ImageStreamMappings via the API are not affected by this policy - typically only administrators or system integrations will have those permissions.
`InternalRegistryHostname`	Sets the hostname for the default internal image registry. The value must be in `hostname[:port]` format. For backward compatibility, users can still use `OPENSHIFT_DEFAULT_REGISTRY` environment variable but this setting overrides the environment variable. When this is set, the internal registry must have its hostname set as well. See setting the registry hostname for more details.
`ExternalRegistryHostname`	ExternalRegistryHostname sets the hostname for the default external image registry. The external hostname should be set only when the image registry is exposed externally. The value is used in `publicDockerImageRepository` field in ImageStreams. The value must be in `hostname[:port]` format.

5.2.9. Kubernetes Master Configuration

Table 5.9. Kubernetes Master Configuration Parameters
Parameter Name	Description
`APILevels`	A list of API levels that should be enabled on startup, v1 as examples.
`DisabledAPIGroupVersions`	A map of groups to the versions (or `*`) that should be disabled.
`KubeletClientInfo`	Contains information about how to connect to kubelets.
`KubernetesMasterConfig`	Holds the necessary configuration options for the Kubernetes master.
`MasterCount`	The number of expected masters that should be running. This value defaults to 1 and may be set to a positive integer, or if set to -1, indicates this is part of a cluster.
`MasterIP`	The public IP address of Kubernetes resources. If empty, the first result from `net.InterfaceAddrs` will be used.
`MasterKubeConfig`	File name for the *.kubeconfig* file that describes how to connect this node to the master.
`ServicesNodePortRange`	The range to use for assigning service public ports on a host. Default 30000-32767.
`ServicesSubnet`	The subnet to use for assigning service IPs.
`StaticNodeNames`	The list of nodes that are statically known.

5.2.10. Network Configuration

Choose the CIDRs in the following parameters carefully, because the IPv4 address space is shared by all users of the nodes. OpenShift Container Platform reserves CIDRs from the IPv4 address space for its own use, and reserves CIDRs from the IPv4 address space for addresses that are shared between the external user and the cluster.

Table 5.10. Network Configuration Parameters
Parameter Name	Description
`ClusterNetworkCIDR`	The CIDR string to specify the global overlay network’s L3 space. This is reserved for the internal use of the cluster networking.
`externalIPNetworkCIDRs`	Controls what values are acceptable for the service external IP field. If empty, no `externalIP` may be set. It may contain a list of CIDRs which are checked for access. If a CIDR is prefixed with !, IPs in that CIDR will be rejected. Rejections will be applied first, then the IP checked against one of the allowed CIDRs. You must ensure this range does not overlap with your nodes, pods, or service CIDRs for security reasons.
`HostSubnetLength`	The number of bits to allocate to each host’s subnet. For example, 8 would mean a /24 network on the host.
`ingressIPNetworkCIDR`	Controls the range to assign ingress IPs from for services of type LoadBalancer on bare metal. It may contain a single CIDR that it will be allocated from. By default `172.46.0.0/16` is configured. For security reasons, you should ensure that this range does not overlap with the CIDRs reserved for external IPs, nodes, pods, or services.
`HostSubnetLength`	The number of bits to allocate to each host’s subnet. For example, 8 would mean a /24 network on the host.
`NetworkConfig`	Provides network options for the node.
`NetworkPluginName`	The name of the network plug-in to use.
`ServiceNetwork`	The CIDR string to specify the service networks.

5.2.11. OAuth Authentication Configuration

Table 5.11. OAuth Configuration Parameters
Parameter Name	Description
`AlwaysShowProviderSelection`	Forces the provider selection page to render even when there is only a single provider.
`AssetPublicURL`	Used for building valid client redirect URLs for external access.
`Error`	A path to a file containing a go template used to render error pages during the authentication or grant flow If unspecified, the default error page is used.
`IdentityProviders`	Ordered list of ways for a user to identify themselves.
`Login`	A path to a file containing a go template used to render the login page. If unspecified, the default login page is used.
`MasterCA`	CA for verifying the TLS connection back to the `MasterURL`.
`MasterPublicURL`	Used for building valid client redirect URLs for external access.
`MasterURL`	Used for making server-to-server calls to exchange authorization codes for access tokens.
`OAuthConfig`	Holds the necessary configuration options for OAuth authentication.
`OAuthTemplates`	Allows for customization of pages like the login page.
`ProviderSelection`	A path to a file containing a go template used to render the provider selection page. If unspecified, the default provider selection page is used.
`SessionConfig`	Holds information about configuring sessions.
`Templates`	Allows you to customize pages like the login page.
`TokenConfig`	Contains options for authorization and access tokens.

5.2.12. Project Configuration

Table 5.12. Project Configuration Parameters
Parameter Name	Description
`DefaultNodeSelector`	Holds default project node label selector.
`ProjectConfig`	Holds information about project creation and defaults.
`ProjectRequestMessage`	The string presented to a user if they are unable to request a project via the project request API endpoint.
`ProjectRequestTemplate`	The template to use for creating projects in response to projectrequest. It is in the format namespace/template and it is optional. If it is not specified, a default template is used.

5.2.13. Scheduler Configuration

Table 5.13. Scheduler Configuration Parameters
Parameter Name	Description
`SchedulerConfigFile`	Points to a file that describes how to set up the scheduler. If empty, you get the default scheduling rules

5.2.14. Security Allocator Configuration

Table 5.14. Security Allocator Parameters
Parameter Name	Description
`MCSAllocatorRange`	Defines the range of MCS categories that will be assigned to namespaces. The format is `<prefix>/<numberOfLabels>[,<maxCategory>]`. The default is s0/2 and will allocate from c0 to c1023, which means a total of 535k labels are available (1024 choose 2 ~ 535k). If this value is changed after startup, new projects may receive labels that are already allocated to other projects. Prefix may be any valid SELinux set of terms (including user, role, and type), although leaving them as the default will allow the server to set them automatically.
`SecurityAllocator`	Controls the automatic allocation of UIDs and MCS labels to a project. If nil, allocation is disabled.
`UIDAllocatorRange`	Defines the total set of Unix user IDs (UIDs) that will be allocated to projects automatically, and the size of the block each namespace gets. For example, 1000-1999/10 will allocate ten UIDs per namespace, and will be able to allocate up to 100 blocks before running out of space. The default is to allocate from 1 billion to 2 billion in 10k blocks (which is the expected size of the ranges container images will use once user namespaces are started).

5.2.15. Service Account Configuration

Table 5.15. Service Account Configuration Parameters
Parameter Name	Description
`LimitSecretReferences`	Controls whether or not to allow a service account to reference any secret in a namespace without explicitly referencing them.
`ManagedNames`	A list of service account names that will be auto-created in every namespace. If no names are specified, the `ServiceAccountsController` will not be started.
`MasterCA`	The CA for verifying the TLS connection back to the master. The service account controller will automatically inject the contents of this file into pods so they can verify connections to the master.
`PrivateKeyFile`	A file containing a PEM-encoded private RSA key, used to sign service account tokens. If no private key is specified, the service account `TokensController` will not be started.
`PublicKeyFiles`	A list of files, each containing a PEM-encoded public RSA key. If any file contains a private key, the public portion of the key is used. The list of public keys is used to verify presented service account tokens. Each key is tried in order until the list is exhausted or verification succeeds. If no keys are specified, no service account authentication will be available.
`ServiceAccountConfig`	Holds the necessary configuration options for a service account.

5.2.16. Serving Information Configuration

Table 5.16. Serving Information Configuration Parameters
Parameter Name	Description
`AllowRecursiveQueries`	Allows the DNS server on the master to answer queries recursively. Note that open resolvers can be used for DNS amplification attacks and the master DNS should not be made accessible to public networks.
`BindAddress`	The ip:port to serve on.
`BindNetwork`	Controls limits and behavior for importing images.
`CertFile`	A file containing a PEM-encoded certificate.
`CertInfo`	TLS cert information for serving secure traffic.
`ClientCA`	The certificate bundle for all the signers that you recognize for incoming client certificates.
`dnsConfig`	Holds the necessary configuration options for DNS.
`DNSDomain`	Holds the domain suffix.
`DNSIP`	Holds the IP.
`KeyFile`	A file containing a PEM-encoded private key for the certificate specified by `CertFile`.
`MasterClientConnectionOverrides`	Provides overrides to the client connection used to connect to the master.
`MaxRequestsInFlight`	The number of concurrent requests allowed to the server. If zero, no limit.
`NamedCertificates`	A list of certificates to use to secure requests to specific host names.
`RequestTimeoutSecond`	The number of seconds before requests are timed out. The default is 60 minutes. If -1, there is no limit on requests.
`ServingInfo`	The HTTP serving information for the assets.

5.2.17. Volume Configuration

Table 5.17. Volume Configuration Parameters
Parameter Name	Description
`DynamicProvisioningEnabled`	A boolean to enable or disable dynamic provisioning. Default is true.
FSGroup	Can be specified to enable a quota on local storage use per unique FSGroup ID. At present this is only implemented for emptyDir volumes, and if the underlying `volumeDirectory` is on an XFS filesystem.
`LocalQuota`	Contains options for controlling local volume quota on the node.
`MasterVolumeConfig`	Contains options for configuring volume plug-ins in the master node.
`NodeVolumeConfig`	Contains options for configuring volumes on the node.
`VolumeConfig`	Contains options for configuring volumes on the node.
`VolumeDirectory`	The directory that volumes are stored under.

5.2.18. Audit Configuration

Audit provides a security-relevant chronological set of records documenting the sequence of activities that have affected system by individual users, administrators, or other components of the system.

Audit works at the API server level, logging all requests coming to the server. Each audit log contains two entries:

The request line containing:
1. A Unique ID allowing to match the response line (see #2)
2. The source IP of the request
3. The HTTP method being invoked
4. The original user invoking the operation
5. The impersonated user for the operation (self meaning himself)
6. The impersonated group for the operation (lookup meaning user’s group)
7. The namespace of the request or <none>
8. The URI as requested
The response line containing:
1. The the unique ID from #1
2. The response code

Example output for user admin asking for a list of pods:

AUDIT: id="5c3b8227-4af9-4322-8a71-542231c3887b" ip="127.0.0.1" method="GET" user="admin" as="<self>" asgroups="<lookup>" namespace="default" uri="/api/v1/namespaces/default/pods"
AUDIT: id="5c3b8227-4af9-4322-8a71-542231c3887b" response="200"

The openshift_master_audit_config variable enables API service auditing. It takes an array of the following options:

Table 5.18. Audit Configuration Parameters
Parameter Name	Description
`enabled`	A boolean to enable or disable audit logs. Default is `false`.
`auditFilePath`	File path where the requests should be logged to. If not set, logs are printed to master logs.
`maximumFileRetentionDays`	Specifies maximum number of days to retain old audit log files based on the time stamp encoded in their filename.
`maximumRetainedFiles`	Specifies the maximum number of old audit log files to retain.
`maximumFileSizeMegabytes`	Specifies maximum size in megabytes of the log file before it gets rotated. Defaults to 100MB.

Example Audit Configuration

auditConfig:
  auditFilePath: "/var/log/audit-ocp.log"
  enabled: true
  maximumFileRetentionDays: 10
  maximumFileSizeMegabytes: 10
  maximumRetainedFiles: 10

Advanced Setup for the Audit Log

If you want more advanced setup for the audit log, you can use:

openshift_master_audit_config={"enabled": true}

The directory in auditFilePath will be created if it does not exist.

openshift_master_audit_config={"enabled": true, "auditFilePath": "/var/log/openpaas-oscp-audit/openpaas-oscp-audit.log", "maximumFileRetentionDays": 14, "maximumFileSizeMegabytes": 500, "maximumRetainedFiles": 5}

5.2.19. Advanced Audit

Important

Advanced audit is a Technology Preview feature and it is subject to change in future releases. Technology Preview features are not supported with Red Hat production service level agreements (SLAs), might not be functionally complete, and Red Hat does not recommend to use them for 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 on Red Hat Technology Preview features support scope, see https://access.redhat.com/support/offerings/techpreview/.

The advanced audit feature provides several improvements over the basic audit functionality, including fine-grained events filtering and multiple output back ends.

To enable the advanced audit feature, provide the following values in the openshift_master_audit_config parameter

openshift_master_audit_config={"enabled": true, "auditFilePath": "/var/log/oscp-audit/-oscp-audit.log", "maximumFileRetentionDays": 14, "maximumFileSizeMegabytes": 500, "maximumRetainedFiles": 5, "policyFile": "/etc/security/adv-audit.yaml", "logFormat":"json"}

Important

The policy file /etc/security/adv-audit.yaml must be available on each master node.

The following table contains additional options you can use.

Table 5.19. Advanced Audit Configuration Parameters
Parameter Name	Description
`policyFile`	Path to the file that defines the audit policy configuration.
`policyConfiguration`	An embedded audit policy configuration.
`logFormat`	Specifies the format of the saved audit logs. Allowed values are `legacy` (the format used in basic audit), and `json`.
`webHookKubeConfig`	Path to a `.kubeconfig`-formatted file that defines the audit webhook configuration, where the events are sent to.
`webHookMode`	Specifies the strategy for sending audit events. Allowed values are `block` (blocks processing another event until the previous has fully processed) and `batch` (buffers events and delivers in batches).

Important

To enable the advanced audit feature, you must provide either policyFile orpolicyConfiguration describing the audit policy rules:

Sample Audit Policy Configuration

apiVersion: audit.k8s.io/v1alpha1
kind: Policy
rules:

  # A catch-all rule to log all other requests at the Metadata level.
  - level: Metadata 1

  # Do not log watch requests by the "system:kube-proxy" on endpoints or services
  - level: None 2
    users: ["system:kube-proxy"] 3
    verbs: ["watch"] 4
    resources: 5
    - group: ""
      resources: ["endpoints", "services"]

  # Do not log authenticated requests to certain non-resource URL paths.
  - level: None
    userGroups: ["system:authenticated"] 6
    nonResourceURLs: 7
    - "/api*" # Wildcard matching.
    - "/version"

  # Log the request body of configmap changes in kube-system.
  - level: Request
    resources:
    - group: "" # core API group
      resources: ["configmaps"]
    # This rule only applies to resources in the "kube-system" namespace.
    # The empty string "" can be used to select non-namespaced resources.
    namespaces: ["kube-system"] 8

  # Log configmap and secret changes in all other namespaces at the metadata level.
  - level: Metadata
    resources:
    - group: "" # core API group
      resources: ["secrets", "configmaps"]

  # Log all other resources in core and extensions at the request level.
  - level: Request
    resources:
    - group: "" # core API group
    - group: "extensions" # Version of group should NOT be included.

  # Log login failures from the web console or CLI. Review the logs and refine your policies.
  - level: Metadata
    nonResourceURLs:
    - /login* 9
    - /oauth* 10

1 2

There are four possible levels every event can be logged at:

None - Do not log events that match this rule.
Metadata - Log request metadata (requesting user, time stamp, resource, verb, etc.), but not request or response body. This is the same level as the one used in basic audit.
Request - Log event metadata and request body, but not response body.
RequestResponse - Log event metadata, request, and response bodies.

3

A list of users the rule applies to. An empty list implies every user.

4

A list of verbs this rule applies to. An empty list implies every verb. This is Kubernetes verb associated with API requests (including get, list, watch, create, update, patch, delete, deletecollection, and proxy).

5

A list of resources the rule applies to. An empty list implies every resource. Each resource is specified as a group it is assigned to (for example, an empty for Kubernetes core API, batch, build.openshift.io, etc.), and a resource list from that group.

6

A list of groups the rule applies to. An empty list implies every group.

7

A list of non-resources URLs the rule applies to.

8

A list of namespaces the rule applies to. An empty list implies every namespace.

9

Endpoint used by the web console.

10

Endpoint used by the CLI.

For more information on advanced audit, see the Kubernetes documentation

5.2.20. Specifying TLS ciphers for etcd

You can specify the supported TLS ciphers to use in communication between the master and etcd servers.

On each etcd node, upgrade etcd:
```
# yum update etcd iptables-services
```
Confirm that your etcd version is 3.2.22 or later:
```
# etcd --version
etcd Version: 3.2.22
```

On each master host, specify the ciphers to enable in the /etc/origin/master/master-config.yaml file:

servingInfo:
  ...
  minTLSVersion: VersionTLS12
  cipherSuites:
  - TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
  - TLS_RSA_WITH_AES_256_CBC_SHA
  - TLS_RSA_WITH_AES_128_CBC_SHA
...

On each master host, restart the master service:

# systemctl restart atomic-openshift-master-api atomic-openshift-master-controllers

Confirm that the cipher is applied. For example, for TLSv1.2 cipher ECDHE-RSA-AES128-GCM-SHA256, run the following command:

# openssl s_client -connect etcd1.example.com:2379 1
CONNECTED(00000003)
depth=0 CN = etcd1.example.com
verify error:num=20:unable to get local issuer certificate
verify return:1
depth=0 CN = etcd1.example.com
verify error:num=21:unable to verify the first certificate
verify return:1
139905367488400:error:14094412:SSL routines:ssl3_read_bytes:sslv3 alert bad certificate:s3_pkt.c:1493:SSL alert number 42
139905367488400:error:140790E5:SSL routines:ssl23_write:ssl handshake failure:s23_lib.c:177:
---
Certificate chain
 0 s:/CN=etcd1.example.com
   i:/CN=etcd-signer@1529635004
---
Server certificate
-----BEGIN CERTIFICATE-----
MIIEkjCCAnqgAwIBAgIBATANBgkqhkiG9w0BAQsFADAhMR8wHQYDVQQDDBZldGNk
........
....
eif87qttt0Sl1vS8DG1KQO1oOBlNkg==
-----END CERTIFICATE-----
subject=/CN=etcd1.example.com
issuer=/CN=etcd-signer@1529635004
---
Acceptable client certificate CA names
/CN=etcd-signer@1529635004
Client Certificate Types: RSA sign, ECDSA sign
Requested Signature Algorithms: RSA+SHA256:ECDSA+SHA256:RSA+SHA384:ECDSA+SHA384:RSA+SHA1:ECDSA+SHA1
Shared Requested Signature Algorithms: RSA+SHA256:ECDSA+SHA256:RSA+SHA384:ECDSA+SHA384:RSA+SHA1:ECDSA+SHA1
Peer signing digest: SHA384
Server Temp Key: ECDH, P-256, 256 bits
---
SSL handshake has read 1666 bytes and written 138 bytes
---
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES128-GCM-SHA256
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : ECDHE-RSA-AES128-GCM-SHA256
    Session-ID:
    Session-ID-ctx:
    Master-Key: 1EFA00A91EE5FC5EDDCFC67C8ECD060D44FD3EB23D834EDED929E4B74536F273C0F9299935E5504B562CD56E76ED208D
    Key-Arg   : None
    Krb5 Principal: None
    PSK identity: None
    PSK identity hint: None
    Start Time: 1529651744
    Timeout   : 300 (sec)
    Verify return code: 21 (unable to verify the first certificate)

1: etcd1.example.com is the name of an etcd host.

5.3. Node Configuration Files

The following node-config.yaml file is a sample node configuration file that was generated with the default values as of writing. You can create a new node configuration file to see the valid options for your installed version of OpenShift Container Platform.

Example 5.1. Sample Node Configuration File

allowDisabledDocker: false
apiVersion: v1
authConfig:
  authenticationCacheSize: 1000
  authenticationCacheTTL: 5m
  authorizationCacheSize: 1000
  authorizationCacheTTL: 5m
dnsDomain: cluster.local
dnsIP: 10.0.2.15 1
dockerConfig:
  execHandlerName: native
imageConfig:
  format: openshift/origin-${component}:${version}
  latest: false
iptablesSyncPeriod: 5s
kind: NodeConfig
masterKubeConfig: node.kubeconfig
networkConfig:
  mtu: 1450
  networkPluginName: ""
nodeIP: ""
nodeName: node1.example.com
podManifestConfig: 2
  path: "/path/to/pod-manifest-file" 3
  fileCheckIntervalSeconds: 30 4
proxyArguments:
  proxy-mode:
  - iptables 5
volumeConfig:
  localQuota:
   perFSGroup: null6
servingInfo:
  bindAddress: 0.0.0.0:10250
  bindNetwork: tcp4
  certFile: server.crt
  clientCA: node-client-ca.crt
  keyFile: server.key
  namedCertificates: null
volumeDirectory: /root/openshift.local.volumes

1: Configures an IP address to be prepended to a pod’s /etc/resolv.conf by adding the address here.
2: Allows pods to be placed directly on certain set of nodes, or on all nodes without going through the scheduler. You can then use pods to perform the same administrative tasks and support the same services on each node.
3: Specifies the path for the pod manifest file or directory. If it is a directory, then it is expected to contain one or more manifest files. This is used by the Kubelet to create pods on the node.
4: This is the interval (in seconds) for checking the manifest file for new data. The interval must be a positive value.
5: The service proxy implementation to use.
6: Preliminary support for local emptyDir volume quotas, set this value to a resource quantity representing the desired quota per FSGroup, per node. (i.e. 1Gi, 512Mi, etc) Currently requires that the volumeDirectory be on an XFS filesystem mounted with the 'gquota' option, and the matching security context contraint’s fsGroup type set to 'MustRunAs'.

The node configuration file determines the resources of a node. See the Allocating node resources section in the Cluster Administrator guide for more information.

5.3.1. Pod and Node Configuration

Table 5.20. Pod and Node Configuration Parameters
Parameter Name	Description
`NodeConfig`	The fully specified configuration starting an OpenShift Container Platform node.
`NodeIP`	Node may have multiple IPs, so this specifies the IP to use for pod traffic routing. If not specified, network parse/lookup on the nodeName is performed and the first non-loopback address is used.
`NodeName`	The value used to identify this particular node in the cluster. If possible, this should be your fully qualified hostname. If you are describing a set of static nodes to the master, this value must match one of the values in the list.
`PodEvictionTimeout`	Controls grace period for deleting pods on failed nodes. It takes valid time duration string. If empty, you get the default pod eviction timeout.
`ProxyClientInfo`	Specifies the client cert/key to use when proxying to pods.

5.3.2. Docker Configuration

Table 5.21. Docker Configuration Parameters
Parameter Name	Description
`AllowDisabledDocker`	If true, the kubelet will ignore errors from Docker. This means that a node can start on a machine that does not have docker started.
`DockerConfig`	Holds Docker related configuration options
`ExecHandlerName`	The handler to use for executing commands in Docker containers.

5.3.3. Parallel Image Pulls with Docker 1.9+

If you are using Docker 1.9+, you may want to consider enabling parallel image pulling, as the default is to pull images one at a time.

Note

There is a potential issue with data corruption prior to Docker 1.9. However, starting with 1.9, the corruption issue is resolved and it is safe to switch to parallel pulls.

kubeletArguments:
  serialize-image-pulls:
  - "false" 1

1: Change to true to disable parallel pulls. (This is the default config)

5.4. Passwords and Other Sensitive Data

For some authentication configurations, an LDAP bindPassword or OAuth clientSecret value is required. Instead of specifying these values directly in the master configuration file, these values may be provided as environment variables, external files, or in encrypted files.

Environment Variable Example

  ...
  bindPassword:
    env: BIND_PASSWORD_ENV_VAR_NAME

External File Example

  ...
  bindPassword:
    file: bindPassword.txt

Encrypted External File Example

  ...
  bindPassword:
    file: bindPassword.encrypted
    keyFile: bindPassword.key

To create the encrypted file and key file for the above example:

$ oc adm ca encrypt --genkey=bindPassword.key --out=bindPassword.encrypted
> Data to encrypt: B1ndPass0rd!

Run oc adm commands only from the first master listed in the Ansible host inventory file, by default /etc/ansible/hosts.

Warning

Encrypted data is only as secure as the decrypting key. Care should be taken to limit filesystem permissions and access to the key file.

5.5. Creating New Configuration Files

When defining an OpenShift Container Platform configuration from scratch, start by creating new configuration files.

For master host configuration files, use the openshift start command with the --write-config option to write the configuration files. For node hosts, use the oc adm create-node-config command to write the configuration files.

The following commands write the relevant launch configuration file(s), certificate files, and any other necessary files to the specified --write-config or --node-dir directory.

Generated certificate files are valid for two years, while the certification authority (CA) certificate is valid for five years. This can be altered with the --expire-days and --signer-expire-days options, but for security reasons, it is recommended to not make them greater than these values.

To create configuration files for an all-in-one server (a master and a node on the same host) in the specified directory:

$ openshift start --write-config=/openshift.local.config

To create a master configuration file and other required files in the specified directory:

$ openshift start master --write-config=/openshift.local.config/master

To create a node configuration file and other related files in the specified directory:

$ oc adm create-node-config \
    --node-dir=/openshift.local.config/node-<node_hostname> \
    --node=<node_hostname> \
    --hostnames=<node_hostname>,<ip_address> \
    --certificate-authority="/path/to/ca.crt" \
    --signer-cert="/path/to/ca.crt" \
    --signer-key="/path/to/ca.key"
    --signer-serial="/path/to/ca.serial.txt"
    --node-client-certificate-authority="/path/to/ca.crt"

When creating node configuration files, the --hostnames option accepts a comma-delimited list of every host name or IP address you want server certificates to be valid for.

5.6. Launching Servers Using Configuration Files

Once you have modified the master and/or node configuration files to your specifications, you can use them when launching servers by specifying them as an argument. Keep in mind that if you specify a configuration file, none of the other command line options you pass are respected.

To launch an all-in-one server using a master configuration and a node configuration file:

$ openshift start --master-config=/openshift.local.config/master/master-config.yaml --node-config=/openshift.local.config/node-<node_hostname>/node-config.yaml

To launch a master server using a master configuration file:

$ openshift start master --config=/openshift.local.config/master/master-config.yaml

To launch a node server using a node configuration file:

$ openshift start node --config=/openshift.local.config/node-<node_hostname>/node-config.yaml

5.7. Configuring Logging Levels

OpenShift Container Platform uses the systemd-journald.service to collect log messages for debugging, using five log message severities. The logging levels are based on Kubernetes logging conventions, as follows:

Table 5.22. Log Level Options
Option	Description
0	Errors and warnings only
2	Normal information
4	Debugging-level information
6	API-level debugging information (request / response)
8	Body-level API debugging information

You can control which INFO messages are logged by setting the loglevel option in the in /etc/sysconfig/atomic-openshift-node, the /etc/sysconfig/atomic-openshift-master-api file and the /etc/sysconfig/atomic-openshift-master-controllers file. Configuring the logs to collect all messages can lead to large logs that are difficult to interpret and can take up excessive space. Collecting all messages should only be used in debug situations.

Note

Messages with FATAL, ERROR, WARNING and some INFO severities appear in the logs regardless of the log configuration.

You can view logs for the master or the node system using the following command:

# journalctl -r -u <journal_name>

Use the -r option to show the newest entries first.

For example:

# journalctl -r -u atomic-openshift-master-controllers
# journalctl -r -u atomic-openshift-master-api
# journalctl -r -u atomic-openshift-node.service

To change the logging level:

Edit the /etc/sysconfig/atomic-openshift-master file for the master or /etc/sysconfig/atomic-openshift-node file for the nodes.
Enter a value from the Log Level Options table above in the OPTIONS=--loglevel= field.
For example:
```
OPTIONS=--loglevel=4
```
Restart the master or node host as appropriate. See Restarting OpenShift Container Platform services.

After the restart, all new log messages will conform to the new setting. Older messages do not change.

Note

The default log level can be set using the Advanced Install. For more information, see Cluster Variables.

The following examples are excerpts from a master journald log at various log levels. Timestamps and system information have been removed from these examples.

Excerpt of journalctl -u atomic-openshift-master-controllers.service output at loglevel=0

4897 plugins.go:77] Registered admission plugin "NamespaceLifecycle"
4897 start_master.go:290] Warning: assetConfig.loggingPublicURL: Invalid value: "": required to view aggregated container logs in the console, master start will continue.
4897 start_master.go:290] Warning: assetConfig.metricsPublicURL: Invalid value: "": required to view cluster metrics in the console, master start will continue.
4897 start_master.go:290] Warning: aggregatorConfig.proxyClientInfo: Invalid value: "": if no client certificate is specified, the aggregator will be unable to proxy to remote servers,
4897 start_master.go:412] Starting controllers on 0.0.0.0:8444 (v3.7.14)
4897 start_master.go:416] Using images from "openshift3/ose-<component>:v3.7.14"
4897 standalone_apiserver.go:106] Started health checks at 0.0.0.0:8444
4897 plugins.go:77] Registered admission plugin "NamespaceLifecycle"
4897 configgetter.go:53] Initializing cache sizes based on 0MB limit
4897 leaderelection.go:105] Attempting to acquire openshift-master-controllers lease as master-bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com-10.19.41.74-xtz6lbqb, renewing every 3s, hold
4897 leaderelection.go:179] attempting to acquire leader lease...
systemd[1]: Started Atomic OpenShift Master Controllers.
4897 leaderelection.go:189] successfully acquired lease kube-system/openshift-master-controllers
4897 event.go:218] Event(v1.ObjectReference{Kind:"ConfigMap", Namespace:"kube-system", Name:"openshift-master-controllers", UID:"aca86731-ffbe-11e7-8d33-525400c845a8", APIVersion:"v1",
4897 start_master.go:627] Started serviceaccount-token controller
4897 factory.go:351] Creating scheduler from configuration: {{ } [{NoVolumeZoneConflict <nil>} {MaxEBSVolumeCount <nil>} {MaxGCEPDVolumeCount <nil>} {MaxAzureDiskVolumeCount <nil>} {Mat
4897 factory.go:360] Registering predicate: NoVolumeZoneConflict
4897 plugins.go:145] Predicate type NoVolumeZoneConflict already registered, reusing.
4897 factory.go:360] Registering predicate: MaxEBSVolumeCount
4897 plugins.go:145] Predicate type MaxEBSVolumeCount already registered, reusing.
4897 factory.go:360] Registering predicate: MaxGCEPDVolumeCount

Excerpt of journalctl -u atomic-openshift-master-controllers.service output at loglevel=2

4897 master.go:47] Initializing SDN master of type "redhat/openshift-ovs-subnet"
4897 master.go:107] Created ClusterNetwork default (network: "10.128.0.0/14", hostSubnetBits: 9, serviceNetwork: "172.30.0.0/16", pluginName: "redhat/openshift-ovs-subnet")
4897 start_master.go:690] Started "openshift.io/sdn"
4897 start_master.go:680] Starting "openshift.io/service-serving-cert"
4897 controllermanager.go:466] Started "namespace"
4897 controllermanager.go:456] Starting "daemonset"
4897 controller_utils.go:1025] Waiting for caches to sync for namespace controller
4897 shared_informer.go:298] resyncPeriod 120000000000 is smaller than resyncCheckPeriod 600000000000 and the informer has already started. Changing it to 600000000000
4897 start_master.go:690] Started "openshift.io/service-serving-cert"
4897 start_master.go:680] Starting "openshift.io/image-signature-import"
4897 start_master.go:690] Started "openshift.io/image-signature-import"
4897 start_master.go:680] Starting "openshift.io/templateinstance"
4897 controllermanager.go:466] Started "daemonset"
4897 controllermanager.go:456] Starting "statefulset"
4897 daemoncontroller.go:222] Starting daemon sets controller
4897 controller_utils.go:1025] Waiting for caches to sync for daemon sets controller
4897 controllermanager.go:466] Started "statefulset"
4897 controllermanager.go:456] Starting "cronjob"
4897 stateful_set.go:147] Starting stateful set controller
4897 controller_utils.go:1025] Waiting for caches to sync for stateful set controller
4897 start_master.go:690] Started "openshift.io/templateinstance"
4897 start_master.go:680] Starting "openshift.io/horizontalpodautoscaling

Excerpt of journalctl -u atomic-openshift-master-controllers.service output at loglevel=4

4897 factory.go:366] Registering priority: Zone
4897 factory.go:401] Creating scheduler with fit predicates 'map[GeneralPredicates:{} CheckNodeMemoryPressure:{} CheckNodeDiskPressure:{} NoVolumeNodeConflict:{} Region:{} NoVolumeZoneC
4897 controller_utils.go:1025] Waiting for caches to sync for tokens controller
4897 controllermanager.go:108] Version: v1.7.6+a08f5eeb62
4897 leaderelection.go:179] attempting to acquire leader lease...
4897 leaderelection.go:189] successfully acquired lease kube-system/kube-controller-manager
4897 event.go:218] Event(v1.ObjectReference{Kind:"ConfigMap", Namespace:"kube-system", Name:"kube-controller-manager", UID:"acb3e9c6-ffbe-11e7-8d33-525400c845a8", APIVersion:"v1", Resou
4897 controller_utils.go:1032] Caches are synced for tokens controller
4897 plugins.go:101] No cloud provider specified.
4897 controllermanager.go:481] "serviceaccount-token" is disabled
4897 controllermanager.go:450] "bootstrapsigner" is disabled
4897 controllermanager.go:450] "tokencleaner" is disabled
4897 controllermanager.go:456] Starting "garbagecollector"
4897 start_master.go:680] Starting "openshift.io/build"
4897 controllermanager.go:466] Started "garbagecollector"
4897 controllermanager.go:456] Starting "deployment"
4897 garbagecollector.go:126] Starting garbage collector controller
4897 controller_utils.go:1025] Waiting for caches to sync for garbage collector controller
4897 controllermanager.go:466] Started "deployment"
4897 controllermanager.go:450] "horizontalpodautoscaling" is disabled
4897 controllermanager.go:456] Starting "disruption"
4897 deployment_controller.go:152] Starting deployment controller

Excerpt of journalctl -u atomic-openshift-master-controllers.service output at loglevel=8

4897 plugins.go:77] Registered admission plugin "NamespaceLifecycle"
4897 start_master.go:290] Warning: assetConfig.loggingPublicURL: Invalid value: "": required to view aggregated container logs in the console, master start will continue.
4897 start_master.go:290] Warning: assetConfig.metricsPublicURL: Invalid value: "": required to view cluster metrics in the console, master start will continue.
4897 start_master.go:290] Warning: aggregatorConfig.proxyClientInfo: Invalid value: "": if no client certificate is specified, the aggregator will be unable to proxy to remote serv
4897 start_master.go:412] Starting controllers on 0.0.0.0:8444 (v3.7.14)
4897 start_master.go:416] Using images from "openshift3/ose-<component>:v3.7.14"
4897 standalone_apiserver.go:106] Started health checks at 0.0.0.0:8444
4897 plugins.go:77] Registered admission plugin "NamespaceLifecycle"
4897 configgetter.go:53] Initializing cache sizes based on 0MB limit
4897 leaderelection.go:105] Attempting to acquire openshift-master-controllers lease as master-bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com-10.19.41.74-xtz6lbqb, renewing every 3s,
4897 leaderelection.go:179] attempting to acquire leader lease...
systemd[1]: Started Atomic OpenShift Master Controllers.
4897 leaderelection.go:189] successfully acquired lease kube-system/openshift-master-controllers
4897 event.go:218] Event(v1.ObjectReference{Kind:"ConfigMap", Namespace:"kube-system", Name:"openshift-master-controllers", UID:"aca86731-ffbe-11e7-8d33-525400c845a8", APIVersion:"
4897 start_master.go:627] Started serviceaccount-token controller

Excerpt of journalctl -u atomic-openshift-master-api.service output at loglevel=2

4613 plugins.go:77] Registered admission plugin "NamespaceLifecycle"
4613 master.go:320] Starting Web Console https://bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com:8443/console/
4613 master.go:329] Starting OAuth2 API at /oauth
4613 master.go:320] Starting Web Console https://bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com:8443/console/
4613 master.go:329] Starting OAuth2 API at /oauth
4613 master.go:320] Starting Web Console https://bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com:8443/console/
4613 master.go:329] Starting OAuth2 API at /oauth
4613 swagger.go:38] No API exists for predefined swagger description /oapi/v1
4613 swagger.go:38] No API exists for predefined swagger description /api/v1
[restful] 2018/01/22 16:53:14 log.go:33: [restful/swagger] listing is available at https://bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com:8443/swaggerapi
[restful] 2018/01/22 16:53:14 log.go:33: [restful/swagger] https://bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com:8443/swaggerui/ is mapped to folder /swagger-ui/
4613 master.go:320] Starting Web Console https://bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com:8443/console/
4613 master.go:329] Starting OAuth2 API at /oauth
4613 swagger.go:38] No API exists for predefined swagger description /oapi/v1
4613 swagger.go:38] No API exists for predefined swagger description /api/v1
[restful] 2018/01/22 16:53:14 log.go:33: [restful/swagger] listing is available at https://bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com:8443/swaggerapi
[restful] 2018/01/22 16:53:14 log.go:33: [restful/swagger] https://bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com:8443/swaggerui/ is mapped to folder /swagger-ui/
Starting Web Console https://bkr-hv03-guest44.dsal.lab.eng.bos.redhat.com:8443/console/
Starting OAuth2 API at /oauth
No API exists for predefined swagger description /oapi/v1
No API exists for predefined swagger description /api/v1

5.8. Restarting OpenShift Container Platform services

To apply configuration changes, you must restart OpenShift Container Platform services.

To restart master, run the command:

# systemctl restart atomic-openshift-master-api atomic-openshift-master-controllers

To restart node hosts, on each node, run the command:
```
# systemctl restart atomic-openshift-node
```

Chapter 5. Master and Node Configuration

5.1. Overview

5.2. Master Configuration Files

5.2.1. Admission Control Configuration

5.2.2. Asset Configuration

5.2.3. Authentication and Authorization Configuration

5.2.4. Controller Configuration

5.2.5. etcd Configuration

5.2.6. Grant Configuration

5.2.7. Image Configuration

5.2.8. Image Policy Configuration

5.2.9. Kubernetes Master Configuration

5.2.10. Network Configuration

5.2.11. OAuth Authentication Configuration

5.2.12. Project Configuration

5.2.13. Scheduler Configuration

5.2.14. Security Allocator Configuration

5.2.15. Service Account Configuration

5.2.16. Serving Information Configuration

5.2.17. Volume Configuration

5.2.18. Audit Configuration

5.2.19. Advanced Audit

5.2.20. Specifying TLS ciphers for etcd

5.3. Node Configuration Files

5.3.1. Pod and Node Configuration

5.3.2. Docker Configuration

5.3.3. Parallel Image Pulls with Docker 1.9+

5.4. Passwords and Other Sensitive Data

5.5. Creating New Configuration Files

5.6. Launching Servers Using Configuration Files

5.7. Configuring Logging Levels

5.8. Restarting OpenShift Container Platform services

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