keycloak-operator

Keycloak Operator

_{Sponsored by Hostzero}

A Kubernetes operator for managing Keycloak resources declaratively. It uses the keycloak.hostzero.com/v1beta1 API group.

Features

• Declarative management of Keycloak resources via Kubernetes CRDs
• Full Keycloak API support via definition fields
• Automatic client secret synchronization to Kubernetes Secrets
• Hierarchical resource management (Instance → Realm → Clients/Users)
• Helm chart for easy deployment
• High availability with leader election

Supported Keycloak Versions

Minimum supported version: 20.0.0

The operator validates the Keycloak version on connection and will fail to become ready if an unsupported version is detected. This ensures compatibility with modern Keycloak APIs and security features.

Note: Red Hat Build of Keycloak (RHBK) versions are also supported as they map to upstream Keycloak versions (e.g., RHBK 24.x corresponds to Keycloak 24.x).

Documentation

📖 Read the full documentation

Overview

This operator manages Keycloak instances and their resources (realms, clients, users, etc.) as Kubernetes Custom Resources. It provides:

• KeycloakInstance / ClusterKeycloakInstance: Connection to a Keycloak server
• KeycloakRealm / ClusterKeycloakRealm: Realm configuration
• KeycloakClient: OAuth2/OIDC client configuration
• KeycloakClientScope: Client scope configuration
• KeycloakProtocolMapper: Token claim mappers
• KeycloakUser: User management
• KeycloakUserCredential: User password management
• KeycloakGroup: Group management
• KeycloakRole: Realm and client roles
• KeycloakRoleMapping: Role-to-user/group assignments
• KeycloakIdentityProvider: External identity providers
• KeycloakComponent: LDAP federation, key providers
• KeycloakOrganization: Organization management (Keycloak 26+)

Architecture

┌─────────────────────────────────────────────────────────────┐
│                    Kubernetes Cluster                        │
│  ┌─────────────────┐    ┌──────────────────────────────────┐│
│  │ Keycloak        │    │  Keycloak Operator                ││
│  │ Operator CRDs   │───▶│  ┌────────────────────────────┐  ││
│  │                 │    │  │ Instance Controller        │  ││
│  │ - Instance      │    │  ├────────────────────────────┤  ││
│  │ - Realm         │    │  │ Realm Controller           │  ││
│  │ - Client        │    │  ├────────────────────────────┤  ││
│  │ - User          │    │  │ Client Controller          │  ││
│  │ - ...           │    │  ├────────────────────────────┤  ││
│  └─────────────────┘    │  │ User Controller            │  ││
│                         │  └────────────────────────────┘  ││
│                         └──────────────┬───────────────────┘│
│                                        │                    │
│                                        ▼                    │
│                         ┌──────────────────────────────────┐│
│                         │         Keycloak Server          ││
│                         │         (Admin REST API)         ││
│                         └──────────────────────────────────┘│
└─────────────────────────────────────────────────────────────┘

Project Structure

keycloak-operator/
├── api/
│   └── v1beta1/           # API types (CRDs)
├── cmd/
│   └── main.go            # Operator entrypoint
├── internal/
│   ├── controller/        # Reconciliation logic
│   └── keycloak/          # Keycloak client wrapper
├── config/
│   ├── crd/               # CRD manifests
│   ├── manager/           # Operator deployment
│   ├── rbac/              # RBAC configuration
│   └── samples/           # Example resources
├── test/
│   └── e2e/               # End-to-end tests
├── charts/
│   └── keycloak-operator/ # Helm chart
├── hack/                  # Development scripts
├── Dockerfile
├── Makefile
└── go.mod

Development

Prerequisites

• Go 1.22+
• Docker
• kubectl
• Kind (brew install kind)
• Helm

Installation

# Install from OCI registry
helm install keycloak-operator oci://ghcr.io/hostzero-gmbh/charts/keycloak-operator \
  --namespace keycloak-operator \
  --create-namespace

Quick Start (Development)

# Create Kind cluster with Keycloak and operator deployed
make kind-all

# Check operator logs
make kind-logs

# Apply sample resources
kubectl apply -f config/samples/

Testing

# Run unit tests (fast, no cluster required)
make test

# Run full E2E tests (requires Kind cluster)
make kind-test

Monitoring

The operator exposes Prometheus metrics at :8080/metrics for observability:

• Reconciliation metrics: Total reconciliations, duration, errors by controller
• Resource metrics: Managed and ready resources by type
• Keycloak connection: Connection status, API request counts and latency

Key alerts to configure:

• Connection failures (keycloak_operator_keycloak_connection_status == 0)
• High error rate (>10% reconciliation failures)
• Resources not ready for extended periods

See the Monitoring Documentation for detailed metrics reference, alerting rules, and Grafana dashboard recommendations.

API Reference

KeycloakInstance

Defines a connection to a Keycloak server.

apiVersion: keycloak.hostzero.com/v1beta1
kind: KeycloakInstance
metadata:
  name: keycloak-instance
spec:
  baseUrl: http://keycloak:8080
  credentials:
    secretName: keycloak-admin
    usernameKey: username
    passwordKey: password

KeycloakRealm

Defines a realm within a Keycloak instance.

apiVersion: keycloak.hostzero.com/v1beta1
kind: KeycloakRealm
metadata:
  name: my-realm
spec:
  instanceRef: keycloak-instance
  definition:
    realm: my-realm
    displayName: My Realm
    enabled: true

KeycloakClient

Defines an OAuth2/OIDC client within a realm.

apiVersion: keycloak.hostzero.com/v1beta1
kind: KeycloakClient
metadata:
  name: my-client
spec:
  realmRef: my-realm
  definition:
    clientId: my-client
    name: My Application
    publicClient: false
    standardFlowEnabled: true
  clientSecret:
    secretName: my-client-secret

Enterprise Support

This operator is developed and maintained by Hostzero GmbH, a provider of sovereign IT infrastructure solutions.

For organizations with critical infrastructure needs (KRITIS), we offer:

• Enterprise support with SLAs
• Security hardening and compliance consulting
• On-premises deployment assistance
• 24/7 incident response
• Training and workshops

Contact us for enterprise licensing and support options.

Contributing

Contributions are welcome! Please read our Contributing Guide for details on our development process and how to submit pull requests.

Security

For security concerns, please see our Security Policy.

License

MIT License - see LICENSE for details.