Keycloak IAM — operator's reference skill

This skill covers running, configuring, deploying, and integrating with Keycloak, the open-source identity & access management server. It targets the modern Quarkus-based distribution (24.x → 26.6.x as of May 2026; the legacy WildFly distribution was removed years ago). Information is current as of Keycloak 26.6.2 (released May 2026).

The Red Hat build of Keycloak (RHBK) is downstream of upstream Keycloak with longer support windows and the same surface area; advice here applies to both unless explicitly noted.

How to use this skill

Keycloak is a large product. Don't try to load everything — route to one or two reference files based on what the user is asking, then go deep.

references/
├── server-config.md         → CLI/env vars, kc.sh, kcadm.sh, hostname, db, cache,
│                              TLS/proxy, logging, features, bootstrap-admin, KCRAW_
├── k8s-deployment.md        → Operator install, Keycloak CR, KeycloakRealmImport,
│                              raw manifests, HA topology, probes, autoscaling
├── security-hardening.md    → Realm policies, brute force, FGAP v2, client policies
│                              (FAPI/OAuth 2.1), DPoP, redirect URI safety, recent CVEs
├── integration.md           → OIDC/SAML flows, IdP brokering, LDAP/AD federation,
│                              themes, SPIs, admin clients (Java/JS/kcadm/Terraform)
├── observability.md         → Metrics, OTLP tracing, structured logging, health
│                              probes, troubleshooting recipes
└── upgrade-and-backup.md    → Upgrade matrix, zero-downtime patches, realm
                               export/import, DB backup, disaster recovery

Routing cheatsheet:

When in doubt about a CLI flag, the source of truth is https://www.keycloak.org/server/all-config (full option index). When in doubt about a CR field, the source of truth is the CRD YAML in keycloak-k8s-resources at the version tag (see §"Authoritative sources" below).

Version map (May 2026)

Latest stable: Keycloak 26.6.2 (released 2026-05-19). 26.6.2 is a security-fix batch — operators on 26.6.0/26.6.1 should upgrade. Do not quote specific CVE IDs from memory; pull the authoritative list with gh api repos/keycloak/keycloak/security-advisories and gh release view 26.6.2 --repo keycloak/keycloak --json body. See security-hardening.md §CVE table for how to surface the current set.

Notable changes through the 26.x line:

Always cross-check with the release-notes body via gh release view <tag> --repo keycloak/keycloak --json body --jq '.body'. Do not rely solely on this table — bump the date and verify.

Authoritative sources

When the user asks about something specific, prefer these sources over generic recall. Cited paths are relative to repo root — access via a local clone, or fetch via gh api repos/<owner>/<repo>/contents/<path>.

• Upstream source (keycloak/keycloak)
• CLI option mappers: quarkus/runtime/src/main/java/org/keycloak/quarkus/runtime/configuration/mappers/*PropertyMappers.java
• Option definitions (descriptions, defaults): quarkus/config-api/src/main/java/org/keycloak/config/*Options.java
• Operator Java code + CRD generators: operator/src/main/java/org/keycloak/operator/
• Themes (login/email/account/admin): themes/src/main/resources/theme/ + js/apps/{account-ui,admin-ui}/
• asciidoc guides operators rarely think to read: docs/guides/server/*.adoc, docs/guides/operator/*.adoc, docs/guides/high-availability/*.adoc

• Operator install manifests (keycloak/keycloak-k8s-resources)
• Each Keycloak version has a git tag (e.g. 26.6.2) with three files under kubernetes/:
• keycloaks.k8s.keycloak.org-v1.yml — the Keycloak CRD
• keycloakrealmimports.k8s.keycloak.org-v1.yml — the KeycloakRealmImport CRD
• kubernetes.yml — Operator Deployment + RBAC + ServiceAccount
• The repo's main branch has only the README + LICENSE; the actual manifests live in tags. Use git checkout <tag> against a clone, or gh api repos/keycloak/keycloak-k8s-resources/contents/kubernetes?ref=<tag> to fetch raw. (Do NOT assume the repo is stale just because main looks empty.)

• Online docs: https://www.keycloak.org/
• /server/all-config — every CLI option, every default
• /server/configuration — concept overview, build-time vs runtime
• /operator/installation, /operator/basic-deployment, /operator/advanced-configuration, /operator/realm, /operator/keycloak-cr, /operator/rolling-updates
• /high-availability/ — multi-cluster, external Infinispan, CloudNativePG recipe
• /securing-apps/ — OIDC layers, SAML, DPoP, JWT-Authz-Grant, MCP authorization server (CIMD)
• /docs/<version>/server_admin/ and /docs/<version>/server_development/ — admin and SPI guides

• gh CLI (per the user's gh-cli-preferred rule):
• Release notes: gh release view <tag> --repo keycloak/keycloak --json body --jq '.body'
• Issues: gh issue view <N> --repo keycloak/keycloak
• Search: gh search issues --repo keycloak/keycloak "<query>"
• Security advisories: gh api repos/keycloak/keycloak/security-advisories

When the user references a specific behavior, check the source clone or CRD YAML before answering — option names, defaults, and JSON field names get renamed across releases (e.g. --proxy edge|reencrypt|passthrough → --proxy-headers xforwarded|forwarded in 26.4; KEYCLOAK_ADMIN → KC_BOOTSTRAP_ADMIN_* in 26.0; the hostname-v2 rewrite). Stale answers are worse than "let me check."

Production guardrails (the checklist that matters)

These are the things that bite operators most. Don't suggest a Keycloak deployment that violates them without a stated reason.

1. Run `kc.sh build` before `start --optimized` in a custom image, or set spec.startOptimized: true only after baking the build. Otherwise startup pays the auto-build cost on every pod start.
2. `--hostname` must be a real, externally-resolvable URL in production, with --hostname-strict=true (default). Do not run with hostname-strict=false outside of dev — it lets clients dictate the issuer.
3. `--proxy-headers=xforwarded|forwarded` is required when behind any reverse proxy that does TLS termination or rewrites the Host header. Pair with --proxy-trusted-addresses to a CIDR that covers the proxy. Without this, login redirects loop.
4. Use `--db postgres` (or another supported vendor). The default dev-file H2 is not for production and silently disables clustering. Postgres is the only DB that gets tested under load by upstream.
5. Use a real container image registry / pin a tag (quay.io/keycloak/keycloak:26.6.2), never latest. The nightly tag is for CI only.
6. Probes go to the management port (default 9000): /health/started, /health/live, /health/ready — not the main HTTP port. As of 26.6, probes return UP during DB migrations so Liquibase can finish without K8s killing the pod.
7. HPA on Keycloak is a trap. Sessions live in clustered Infinispan caches; scaling out and back in churns the cache. Run a fixed number of replicas (≥3 for HA) with a PodDisruptionBudget, not an HPA.
8. Realm exports are NOT backups. They omit secrets, federated users, and event history. The Postgres database is the source of truth — back that up with WAL archiving (CloudNativePG, Crunchy, RDS automated backups).
9. Bootstrap admin is temporary. KC_BOOTSTRAP_ADMIN_USERNAME/PASSWORD exists only to create the first real admin via kcadm.sh, then should be removed. The bootstrap admin auto-expires after 120 minutes.
10. Pin Keycloak ↔ Operator versions together. The operator at tag 26.6.2 is meant to manage Keycloak 26.6.2. Mixing major.minor versions across the operator/server boundary is unsupported and often breaks the CRD schema.

Quickstart: the smallest production-shaped Keycloak

When the user says "just stand one up so I can play," don't point them at kc.sh start-dev if they care about production fidelity — show them this instead. It's a Keycloak CR + Postgres + Ingress, no extra moving parts:

# 1. Install the operator (do this once per cluster)
# kubectl apply -f https://raw.githubusercontent.com/keycloak/keycloak-k8s-resources/26.6.2/kubernetes/keycloaks.k8s.keycloak.org-v1.yml
# kubectl apply -f https://raw.githubusercontent.com/keycloak/keycloak-k8s-resources/26.6.2/kubernetes/keycloakrealmimports.k8s.keycloak.org-v1.yml
# kubectl apply -f https://raw.githubusercontent.com/keycloak/keycloak-k8s-resources/26.6.2/kubernetes/kubernetes.yml

# 2. Create a TLS secret (cert-manager / hand-roll / etc.)
# 3. Create DB credentials secret (keys: username, password)
# 4. Deploy Keycloak
apiVersion: k8s.keycloak.org/v2alpha1
kind: Keycloak
metadata:
  name: keycloak
  namespace: iam
spec:
  instances: 2
  image: quay.io/keycloak/keycloak:26.6.2
  startOptimized: false           # set true when the image is pre-baked with `kc.sh build`
  hostname:
    hostname: https://auth.example.com
    strict: true
  proxy:
    headers: xforwarded
  http:
    tlsSecret: keycloak-tls       # remove and use ingress for edge termination
  db:
    vendor: postgres
    host: postgres-rw.iam.svc
    database: keycloak
    usernameSecret: { name: keycloak-db, key: username }
    passwordSecret: { name: keycloak-db, key: password }
  bootstrapAdmin:
    user:
      secret: keycloak-bootstrap-admin   # keys: username, password
  update:
    strategy: Auto                # zero-downtime patch updates (26.6+)
  features:
    enabled: ["organizations", "admin-fine-grained-authz:v2"]

See assets/examples/ for fuller examples (with HA tuning, KeycloakRealmImport, raw-manifest deployment without the operator, network policies).

Common operator pitfalls

• `hostname-strict=false` "fixes" my login → No, it papers over a proxy/headers misconfig. Set --proxy-headers correctly instead.
• "Why is my custom theme not appearing?" → The theme must be baked into a custom image and kc.sh build re-run; dropping a theme jar into a stock image at runtime no longer works. Themes are packaged into the optimized server jar.
• "Operator pod logs are flooded with warnings" → On 26.6.0 exactly, that's #47872, fixed in 26.6.1. Upgrade to the latest 26.6.x.
• "Realm import keeps failing on existing realm" → KeycloakRealmImport is create-or-replace; it won't merge. Use kcadm.sh for incremental edits, or accept the realm-as-config GitOps trade-off.
• "My JS admin client is broken on 26.6.0" → 26.6.0 shipped a broken @keycloak/keycloak-admin-client package, fixed in 26.6.1. Use the latest 26.6.x.
• "Liquibase changelock stuck" → A previous migration crashed mid-flight. DELETE FROM DATABASECHANGELOGLOCK WHERE ID=1 (after confirming no other instance is migrating). See observability.md §troubleshooting for the safe procedure.
• *"I'm getting `KC_ substitution surprises with $ in passwords"** → Use the new KCRAW_` prefix (26.6+) instead of `KC_ for any value that contains $`.

Style

• When citing options, give the exact flag and the env var: `--proxy-headers / KC_PROXY_HEADERS `. Operators copy-paste; getting it half right costs them an hour.
• Prefer linking to the source file or release-notes URL the user can verify, over restating from memory. Releases between 26.0 and 26.6 renamed flags and removed others; "I'm pretty sure" is wrong about half the time.
• When the user is on a pre-26 version, surface the upgrade urgency briefly (a one-liner pointing at the upgrade guide). Don't lecture.
• The user is sophisticated — skip the "Keycloak is an open-source IAM solution from Red Hat" preamble. Get to the answer.