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Keycloak installation on Kubernetes

Keycloak is "an open source identity and access management solution". Using a local database, or a variety of backends (think OpenLDAP), you can provide Single Sign-On (SSO) using OpenID, OAuth 2.0, and SAML.

Keycloak Screenshot

Keycloak's OpenID provider can also be used to provide OIDC-based authentication to your Kubernetes cluster, or in combination with Traefik Forward Auth, to protect vulnerable services with an extra layer of authentication.

Keycloak requirements

Ingredients

Already deployed:

Optional:

Preparation

Keycloak Namespace

We need a namespace to deploy our HelmRelease and associated YAMLs into. Per the flux design, I create this example yaml in my flux repo at /bootstrap/namespaces/namespace-keycloak.yaml:

/bootstrap/namespaces/namespace-keycloak.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: keycloak

Keycloak HelmRepository

We're going to install the Keycloak helm chart from the bitnami repository, so I create the following in my flux repo (assuming it doesn't already exist):

/bootstrap/helmrepositories/helmrepository-bitnami.yaml
apiVersion: source.toolkit.fluxcd.io/v1beta1
kind: HelmRepository
metadata:
  name: bitnami
  namespace: flux-system
spec:
  interval: 15m
  url: oci://registry-1.docker.io/bitnamicharts/keycloak

Keycloak Kustomization

Now that the "global" elements of this deployment (just the HelmRepository in this case) have been defined, we do some "flux-ception", and go one layer deeper, adding another Kustomization, telling flux to deploy any YAMLs found in the repo at /keycloak/. I create this example Kustomization in my flux repo:

/bootstrap/kustomizations/kustomization-keycloak.yaml
apiVersion: kustomize.toolkit.fluxcd.io/v1beta2
kind: Kustomization
metadata:
  name: keycloak
  namespace: flux-system
spec:
  interval: 30m
  path: ./keycloak
  prune: true # remove any elements later removed from the above path
  timeout: 10m # if not set, this defaults to interval duration, which is 1h
  sourceRef:
    kind: GitRepository
    name: flux-system
  healthChecks:
    - apiVersion: helm.toolkit.fluxcd.io/v2beta1
      kind: HelmRelease
      name: keycloak
      namespace: keycloak

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Keycloak DNSEndpoint

If, like me, you prefer to create your DNS records the "GitOps way" using ExternalDNS, create something like the following example to create a DNS entry for your Authentik ingress:

/keycloak/dnsendpoint-keycloak.example.com.yaml
apiVersion: externaldns.k8s.io/v1alpha1
kind: DNSEndpoint
metadata:
  name: "keycloak.example.com"
  namespace: keycloak
spec:
  endpoints:
  - dnsName: "keycloak.example.com"
    recordTTL: 180
    recordType: CNAME
    targets:
    - "traefik-ingress.example.com"

Tip

Rather than creating individual A records for each host, I prefer to create one A record (nginx-ingress.example.com in the example above), and then create individual CNAME records pointing to that A record.

Keycloak HelmRelease

Lastly, having set the scene above, we define the HelmRelease which will actually deploy keycloak into the cluster. We start with a basic HelmRelease YAML, like this example:

/keycloak/helmrelease-keycloak.yaml
apiVersion: helm.toolkit.fluxcd.io/v2beta1
kind: HelmRelease
metadata:
  name: keycloak
  namespace: keycloak
spec:
  chart:
    spec:
      chart: keycloak
      version: 17.3.x # auto-update to semver bugfixes only (1)
      sourceRef:
        kind: HelmRepository
        name: bitnami
        namespace: flux-system
  interval: 15m
  timeout: 5m
  releaseName: keycloak
  values: # paste contents of upstream values.yaml below, indented 4 spaces (2)
  1. I like to set this to the semver minor version of the Keycloak current helm chart, so that I'll inherit bug fixes but not any new features (since I'll need to manually update my values to accommodate new releases anyway)
  2. Paste the full contents of the upstream values.yaml here, indented 4 spaces under the values: key

If we deploy this helmrelease as-is, we'll inherit every default from the upstream Keycloak helm chart. That's probably hardly ever what we want to do, so my preference is to take the entire contents of the Keycloak helm chart's values.yaml, and to paste these (indented), under the values key. This means that I can then make my own changes in the context of the entire values.yaml, rather than cherry-picking just the items I want to change, to make future chart upgrades simpler.

Why not put values in a separate ConfigMap?

Didn't you previously advise to put helm chart values into a separate ConfigMap?

Yes, I did. And in practice, I've changed my mind.

Why? Because having the helm values directly in the HelmRelease offers the following advantages:

  1. If you use the YAML extension in VSCode, you'll see a full path to the YAML elements, which can make grokking complex charts easier.
  2. When flux detects a change to a value in a HelmRelease, this forces an immediate reconciliation of the HelmRelease, as opposed to the ConfigMap solution, which requires waiting on the next scheduled reconciliation.
  3. Renovate can parse HelmRelease YAMLs and create PRs when they contain docker image references which can be updated.
  4. In practice, adapting a HelmRelease to match upstream chart changes is no different to adapting a ConfigMap, and so there's no real benefit to splitting the chart values into a separate ConfigMap, IMO.

Then work your way through the values you pasted, and change any which are specific to your configuration.

Configure Keycloak Helm Chart

The following sections detail suggested changes to the values pasted into /keycloak/helmrelease-keycloak.yaml from the Keycloak helm chart's values.yaml. The values are already indented correctly to be copied, pasted into the HelmRelease, and adjusted as necessary.

Ingress

Setup your ingress for the Keycloak UI, enabling at least ingress.enabled as below, and additional TLS options as necessary1:

Configure your ingress
    ingress:
      ## @param ingress.enabled Enable ingress record generation for Keycloak
      ##
      enabled: false

Either leave blank to accept the default ingressClassName, or set to whichever ingress controller you want to use.

Install Keycloak!

Commit the changes to your flux repository, and either wait for the reconciliation interval, or force a reconcilliation using flux reconcile source git flux-system. You should see the kustomization appear...

~ ❯ flux get kustomizations keycloak
NAME        READY   MESSAGE                         REVISION        SUSPENDED
keycloak    True    Applied revision: main/70da637  main/70da637    False
~ ❯

The helmrelease should be reconciled...

~ ❯ flux get helmreleases -n keycloak keycloak
NAME        READY   MESSAGE                             REVISION    SUSPENDED
keycloak    True    Release reconciliation succeeded    v17.3.x     False
~ ❯

And you should have happy pods in the keycloak namespace:

~ ❯ k get pods -n keycloak
NAME                                READY   STATUS      RESTARTS        AGE
keycloak-0                          1/1     Running     1 (3d17h ago)   26d
keycloak-postgresql-0               1/1     Running     1 (3d17h ago)   26d
~ ❯

Browse to the URL you configured in your ingress above, and confirm that the Keycloak UI is displayed. Login with the admin user you defined above, and confirm a successful login.

Create Keycloak user

Why are we adding a user when I have an admin user already?

Do you keep a spare set of house keys somewhere other than your house? Do you login as root onto all your systems? Think of this as the same prinicple - lock the literal admin account away somewhere as a "password of last resort", and create a new user for your day-to-day interaction with Keycloak.

Within the "Master" realm (no need for more realms unless you want to), navigate to Manage -> Users, and then click Add User at the top right:

Navigating to the add user interface in Keycloak

Populate your new user's username (it's the only mandatory field)

Populating a username in the add user interface in Keycloak

Set Keycloak user credentials

Once your user is created, to set their password, click on the "Credentials" tab, and procede to reset it. Set the password to non-temporary, unless you like extra work!

Resetting a user's password in Keycloak

Summary

What have we achieved? We've got Keycloak running and accessible, we've created our normal-use user, and we're ready to flex 💪 the power of Keycloak to deploy an OIDC provider for Kubernetes, or to provide OIDC to Traefik Forward Auth to protect vulnerable UIs!

Summary

Created:

  • Keycloak running and ready for authentication 🔒 !

Next:

Chef's notes 📓

  1. There's a trick to using a single cert across multiple Ingresses or IngressRoutes (coming soon) ↩

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Keycloak resources 📝

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