Advanced configuration

How to tune advanced aspects of the Keycloak CR

Advanced configuration

This guide describes how to use Custom Resources (CRs) for advanced configuration of your Keycloak deployment.

Server configuration details

Many server options are exposed as first-class citizen fields in the Keycloak CR. The structure of the CR is based on the configuration structure of Keycloak. For example, to configure the https-port of the server, follow a similar pattern in the CR and use the httpsPort field. The following example is a complex server configuration; however, it illustrates the relationship between server options and the Keycloak CR:

apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  db:
    vendor: postgres
    usernameSecret:
      name: usernameSecret
      key: usernameSecretKey
    passwordSecret:
      name: passwordSecret
      key: passwordSecretKey
    host: host
    database: database
    port: 123
    schema: schema
    poolInitialSize: 1
    poolMinSize: 2
    poolMaxSize: 3
  http:
    httpEnabled: true
    httpPort: 8180
    httpsPort: 8543
    tlsSecret: my-tls-secret
  hostname:
    hostname: https://my-hostname.tld
    admin: https://my-hostname.tld/admin
    strict: false
    backchannelDynamic: true
  features:
    enabled:
      - docker
      - authorization
    disabled:
      - admin
      - step-up-authentication
  transaction:
    xaEnabled: false

For a list of options, see the Keycloak CRD. For details on configuring options, see All configuration.

Additional options

Some expert server options are unavailable as dedicated fields in the Keycloak CR. The following are examples of omitted fields:

  • Fields that require deep understanding of the underlying Keycloak implementation

  • Fields that are not relevant to a Kubernetes environment

  • Fields for provider configuration because they are dynamic based on the used provider implementation

The additionalOptions field of the Keycloak CR enables Keycloak to accept any available configuration in the form of key-value pairs. You can use this field to include any option that is omitted in the Keycloak CR. For details on configuring options, see All configuration.

The values can be expressed as plain text strings or Secret object references as shown in this example:

apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  ...
  additionalOptions:
    - name: spi-connections-http-client-default-connection-pool-size
      secret: # Secret reference
        name: http-client-secret # name of the Secret
        key: poolSize # name of the Key in the Secret
    - name: spi-email-template-mycustomprovider-enabled
      value: true # plain text value
The name format of options defined in this way is identical to the key format of options specified in the configuration file. For details on various configuration formats, see Configuring Keycloak.

Secret References

Secret References are used by some dedicated options in the Keycloak CR, such as tlsSecret, or as a value in additionalOptions.

Similarly ConfigMap References are used by options such as the configMapFile.

When specifying a Secret or ConfigMap Reference, make sure that a Secret or ConfigMap containing the referenced keys is present in the same namespace as the CR referencing it.

The operator will poll approximately every minute for changes to referenced Secrets or ConfigMaps. When a meaningful change is detected, the Operator performs a rolling restart of the Keycloak Deployment to pick up the changes.

Unsupported features

The unsupported field of the CR contains highly experimental configuration options that are not completely tested and are Tech Preview.

Pod Template

The Pod Template is a raw API representation that is used for the Deployment Template. This field is a temporary workaround in case no supported field exists at the top level of the CR for your use case.

The Operator merges the fields of the provided template with the values generated by the Operator for the specific Deployment. With this feature, you have access to a high level of customizations. However, no guarantee exists that the Deployment will work as expected.

The following example illustrates injecting labels, annotations, volumes, and volume mounts:

apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  ...
  unsupported:
    podTemplate:
      metadata:
        labels:
          my-label: "keycloak"
      spec:
        containers:
          - volumeMounts:
              - name: test-volume
                mountPath: /mnt/test
        volumes:
          - name: test-volume
            secret:
              secretName: keycloak-additional-secret

Disabling required options

Keycloak and the Keycloak Operator provide the best production-ready experience with security in mind. However, during the development phase, you can disable key security features.

Specifically, you can disable the hostname and TLS as shown in the following example:

apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  ...
  http:
    httpEnabled: true
  hostname:
    strict: false

Resource requirements

The Keycloak CR allows specifying the resources options for managing compute resources for the Keycloak container. It provides the ability to request and limit resources independently for the main Keycloak deployment via the Keycloak CR, and for the realm import Job via the Realm Import CR.

When no values are specified, the default requests memory is set to 1700MiB, and the limits memory is set to 2GiB. These values were chosen based on a deeper analysis of Keycloak memory management.

If no values are specified in the Realm Import CR, it falls back to the values specified in the Keycloak CR, or to the defaults as defined above.

You can specify your custom values based on your requirements as follows:

apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  ...
  resources:
    requests:
      cpu: 1200m
      memory: 896Mi
    limits:
      cpu: 6
      memory: 3Gi

Moreover, the Keycloak container manages the heap size more effectively by providing relative values for the heap size. It is achieved by providing certain JVM options.

For more details, see Running Keycloak in a container.

Scheduling

You may control several aspects of the server Pod scheduling via the Keycloak CR. The scheduling stanza exposes optional standard Kubernetes affinity, tolerations, topology spread constraints, and the priority class name to fine tune the scheduling and placement of your server Pods.

An example utilizing all scheduling fields:

apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  scheduling:
    priorityClassName: custom-high
    affinity:
      podAffinity:
        preferredDuringSchedulingIgnoredDuringExecution:
        - podAffinityTerm:
            labelSelector:
              matchLabels:
                app: keycloak
                app.kubernetes.io/managed-by: keycloak-operator
                app.kubernetes.io/component: server
                topologyKey: topology.kubernetes.io/zone
              weight: 10
    tolerations:
    - key: "some-taint"
      operator: "Exists"
      effect: "NoSchedule"
    topologySpreadConstraints:
    - maxSkew: 1
      topologyKey: kubernetes.io/hostname
      whenUnsatisfiable: DoNotSchedule
      ...
  ...

Please see the kubernetes docs for more on scheduling concepts.

If you do not specify a custom affinity, your Pods will have an affinity for the same zone and an anti-affinity for the same node to improve availability. Scheduling to the same zone if possible helps prevent stretch clusters where cross zone cache cluster traffic may have too high of a latency.

Management Interface

To change the port of the management interface, use the first-class citizen field httpManagement.port in the Keycloak CR. To change the properties of the management interface, you can do it by providing additionalOptions field.

You can specify the port and the additionalOptions as follows:

apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  httpManagement:
    port: 9001
  additionalOptions:
    - name: http-management-relative-path
      value: /management
If you are using a custom image, the Operator is unaware of any configuration options that might’ve been specified there. For instance, it may cause that the management interface uses the https schema, but the Operator accesses it via http when the TLS settings is specified in the custom image. To ensure proper TLS configuration, use the tlsSecret and truststores fields in the Keycloak CR so that the Operator can reflect that.

For more details, see Configuring the Management Interface.

Truststores

If you need to provide trusted certificates, the Keycloak CR provides a top level feature for configuring the server’s truststore as discussed in Configuring trusted certificates.

Use the truststores stanza of the Keycloak spec to specify Secrets containing PEM encoded files, or PKCS12 files with extension .p12, .pfx, or .pkcs12, for example:

apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  ...
  truststores:
    my-truststore:
      secret:
        name: my-secret

Where the contents of my-secret could be a PEM file, for example:

apiVersion: v1
kind: Secret
metadata:
  name: my-secret
stringData:
  cert.pem: |
    -----BEGIN CERTIFICATE-----
    ...

When running on a Kubernetes or OpenShift environment well-known locations of trusted certificates are included automatically. This includes /var/run/secrets/kubernetes.io/serviceaccount/ca.crt and the /var/run/secrets/kubernetes.io/serviceaccount/service-ca.crt when present.

Admin Bootstrapping

When you create a new instance the Keycloak CR spec.bootstrapAdmin stanza may be used to configure the bootstrap user and/or service account. If you do not specify anything for the spec.bootstrapAdmin, the operator will create a Secret named "metadata.name"-initial-admin with a username temp-admin and a generated password. If you specify a Secret name for bootstrap admin user, then the Secret will need to contain username and password key value pairs. If you specify a Secret name for bootstrap admin service account, then the Secret will need to contain client-id and client-secret key value pairs.

If a master realm has already been created for you cluster, then the spec.boostrapAdmin is effectively ignored. If you need to create a recovery admin account, then you’ll need to run the CLI command against a Pod directly.

For more information on how to bootstrap a temporary admin user or service account and recover lost admin access, refer to the Admin bootstrap and recovery guide.

Tracing (OpenTelemetry)

Tracing allows for detailed monitoring of each request’s lifecycle, which helps quickly identify and diagnose issues, leading to more efficient debugging and maintenance.

You can change tracing configuration via Keycloak CR fields as follows:

apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  tracing:
    enabled: true                             # default 'false'
    endpoint: http://my-tracing:4317          # default 'http://localhost:4317'
    samplerType: parentbased_traceidratio     # default 'traceidratio'
    samplerRatio: 0.01                        # default '1'
    resourceAttributes:
      some.attribute: something
  additionalOptions:
    - name: tracing-jdbc-enabled
      value: false                            # default 'true'

These fields should reflect 1:1 association with tracing-* options that contain more information.

The tracing-jdbc-enabled is not promoted as a first-class citizen as it might not be well managed in the future, so it needs to be set via the additionalOptions field.

For more details about tracing, see Enabling Tracing.

Network Policies (Preview)

NetworkPolicies allow you to specify rules for traffic flow within your cluster, and also between Pods and the outside world. Your cluster must use a network plugin that supports NetworkPolicy enforcement.

The operator can automatically create a NetworkPolicy to deny access to the clustering port of your Keycloak Pods. The HTTP(S) endpoint is open to traffic from any namespace and the outside world. To enable the NetworkPolicy, set spec.networkPolicy.enabled in your Keycloak CR, as shown in the example below.

Keycloak CR with Network Policies enabled
apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  networkPolicy:
    enabled: true

The above example allows traffic from all sources. The Keycloak CR can be extended to include a list of rules for each of the endpoints exposed by Keycloak. These rules specify from where (the source) the traffic is allowed and it’s possible to communicate with the Keycloak Pods.

Extended Network Policy configuration
apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  networkPolicy:
    enabled: true
    http: <list of rules> (1)
    https: <list of rules> (2)
    management: <list of rules> (3)
1 It defines the rules for HTTP endpoint (port 8080 by default). Due to security reasons, the HTTP endpoint is disabled by default.
2 It defines the access rules for HTTPS endpoint (port 8443 by default.
3 It defines the access rules for management endpoint (port 9000 by default). The management endpoint is used by the Kubernetes Probes and to expose the Keycloak metrics.

The rule syntax is the same as the one used by the Kubernetes Network Policy. It makes it easy to migrate your existing rules into your Keycloak CP. For more information, check the rule syntax.

Example with OpenShift

For a concrete example, let’s imagine we have a Keycloak deployment running in a OpenShift cluster. Users have to access Keycloak to login, so Keycloak must be accessible from the Internet.

To make this example more interesting, let’s assume the Keycloak is monitored too. The monitoring is enabled as described in the OpenShift documentation page: enabling Monitoring for user defined projects.

Based on those requirements, the Keycloak CR would be like this (most parts are omitted, like DB connection and security):

Keycloak CR
apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: example-kc
spec:
  ingress:
    enabled: true (1)
  networkPolicy:
    enabled: true
    https:
    - namespaceSelector:
        matchLabels:
          kubernetes.io/metadata.name: openshift-ingress (2)
    management:
    - namespaceSelector:
        matchLabels:
          kubernetes.io/metadata.name: openshift-user-workload-monitoring (3)
1 Enables Ingress for outside access.
2 The default OpenShift Ingress class pods are running in openshift-ingress namespace. We allow traffic from these pods to access the Keycloak HTTPS endpoint. The traffic from outside the OpenShift cluster goes through these pods.
3 Prometheus pods are running in openshift-user-workload-monitoring. They need to access Keycloak to scrape the available metrics.

Check the Kubernetes Network Policies documentation for more information about NetworkPolicies.

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