Implementing OAuth2 Authorization with Keycloak and Gatekeeper

Implementing OAuth2 Authorization with Keycloak and Gatekeeper

Keycloak Overview

Keycloak is an open-source IAM platform provided by Red Hat’s JBoss. It supports various authentication and authorization protocols, including OpenID Connect (OIDC) and SAML 2.0.

Setting Up Keycloak

• Install Keycloak: Download and install Keycloak or use a Docker image.

• Create a Realm: Set up a realm in the Keycloak administration console.

• Create a Client: Define a client application, set Client ID, and configure redirect URLs.

Configuring Keycloak Gatekeeper

Keycloak Gatekeeper is an authentication proxy that integrates with Keycloak.

discovery-url: https://your-keycloak-instance.com/auth/realms/your-realm/.well-known/openid-configuration

  client-id: gatekeeper-client
  client-secret: your-client-secret
  encryption-key: your-encryption-key
  redirect-url: https://your-application-url.com
  resources:
    - uri: /protected-path
      methods:
        - GET
        - POST
  

Integrating with Kubernetes

To integrate Gatekeeper with Kubernetes, use ingress annotations:

  apiVersion: networking.k8s.io/v1
  kind: Ingress
  metadata:
    name: protected-ingress
    annotations:
      nginx.ingress.kubernetes.io/auth-type: "oauth2"
  spec:
    rules:
    - host: your-application-url.com
      http:
        paths:
        - path: /protected-path
          pathType: Prefix
          backend:
            service:
              name: your-service-name
              port:
                number: 80
                

Accessing and Decoding JSON Web Tokens (JWTs)

Decode JWTs in your application:

  import jwt

  def decode_jwt(token):
      try:
          payload = jwt.decode(token, 
          options=`{"verify_signature": False}`)
          return payload
      except jwt.ExpiredSignatureError:
          return "Token has expired"
      except jwt.InvalidTokenError:
          return "Invalid token"

Conclusion

Using Keycloak and Gatekeeper for OAuth2 authorization enhances security and centralizes authentication management, making it ideal for Kubernetes deployments.