I am trying to use Keycloak with Oauth2 to secure kubernetes-dashboard. I found several post about this error, but none was specific for my problem. maybe i just miss a simple step ..

so far i followed this guide: https://jamesveitch.com/homelab/02.idam/02.keycloak/

Keycloak is installed at the kubernetes cluster within the namespace keycloak. Kubernetes-dashboard is installed within the namespace kubernetes-dashboard.

Keycloak is reachable under auth.mydomain.com and the dashboard should be reachbale under dashboard.mydomain.com.

I have created a user "test" and assigned a group kubernetes-admin which i would use to grant access to the dashboard.

I configured Keycloak like this:

1. Created a new realm "dev"
2. Created a User test and a group kubernetes-admin
3. Created a new client "dashboard"
   • Access Type: confidential
   • Service Account enabled: on
   • Valid Redirect Url: https://dashboard.mydomain.com/oauth/callback
   • Created a Mapper for groups (Type: Group Membership, TokenClaimName:groups)

For Clusterbinding of kubernetes-admin i use this yaml:

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: keycloak-admin-group
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  # NOTE: This is a super administrator and can do everything.
  # Consider a dedicated role in your actual operation.
  name: cluster-admin
subjects:
- kind: Group
  name: kubernetes-admin

For the Configuration of OAuth2 and Ingress i use:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    kubernetes.io/tls-acme: "true"
    ingress.kubernetes.io/ssl-redirect: "true"
    ingress.kubernetes.io/use-port-in-redirects: "true"
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
    nginx.ingress.kubernetes.io/auth-url: "https://$host/oauth2/auth"
    nginx.ingress.kubernetes.io/auth-signin: "https://$host/oauth2/start?rd=$escaped_request_uri"
  name: dashboard
  namespace: kubernetes-dashboard
spec:
  tls:
  - hosts:
    - dashboard.mydomain.com
    secretName: dashboard.mydomain.com-tls
  rules:
  - host: dashboard.mydomain.com
    http:
      paths:
      - backend:
          serviceName: kubernetes-dashboard
          servicePort: 443
        path: /
---
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: oauth2-proxy
  namespace: kubernetes-dashboard
spec:
  rules:
  - host: dashboard.mydomain.com
    http:
      paths:
      - backend:
          serviceName: oauth2-proxy
          servicePort: 4180
        path: /oauth2
  tls:
  - hosts:
    - dashboard.mydomain.com
    secretName: dashboard.mydomain.com-tls
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    k8s-app: oauth2-proxy
  name: oauth2-proxy
  namespace: kubernetes-dashboard
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s-app: oauth2-proxy
  template:
    metadata:
      labels:
        k8s-app: oauth2-proxy
    spec:
      containers:
      - args:
        - --provider=keycloak
        - --client-id=dashboard
        - --client-secret=a27b97fb-eafc-420c-88ba-8017beb54180
        - --login-url=https://auth.mydomain.com/auth/realms/dev/protocol/openid-connect/auth
        - --redeem-url=https://auth.mydomain.com/auth/realms/dev/protocol/openid-connect/token
        - --validate-url=https://auth.mydomain.com/auth/realms/dev/protocol/openid-connect/userinfo
        - --keycloak-group=kubernetes-admin
        - --email-domain=*
        - --http-address=0.0.0.0:4180
        - --reverse-proxy=true
        - --pass-access-token=true
        - --set-xauthrequest=true
        - --ssl-insecure-skip-verify=true
        - --ssl-upstream-insecure-skip-verify=true
        - --cookie-domain=.mydomain.com
        - --whitelist-domain=.mydomain.com
        - --upstream=https://kubernetes-dashboard.kubernetes-dashboard.svc.cluster.local
        # Register a new application
        # https://github.com/settings/applications/new
        env:
        # docker run -ti --rm python:3-alpine python -c 'import secrets,base64;     print(base64.b64encode(base64.b64encode(secrets.token_bytes(16))));'
        - name: OAUTH2_PROXY_COOKIE_SECRET
          value: ekNsWlN6MkphVVVmTnNZUTBEZnZVQT09
        image: quay.io/oauth2-proxy/oauth2-proxy
        imagePullPolicy: Always
        name: oauth2-proxy
        ports:
        - containerPort: 4180
          protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  labels:
    k8s-app: oauth2-proxy
  name: oauth2-proxy
  namespace: kubernetes-dashboard
spec:
  ports:
  - name: http
    port: 4180
    protocol: TCP
    targetPort: 4180
  selector:
    k8s-app: oauth2-proxy

This yaml file is used for a development enviroment with letsencrypt-staging and should ignore ssl errors.

What works is, that i can open https://dashboard.mydomain.com/oauth2/signin and press Sigin with Keycloak. But next i am redirect to 403 Permission Error Page.. The oauth2 logs says: Error on /oauth2/callback?error=invalid_request&error_description=Invalid+scopes

Please keep in Mind that i would like to use a upstream the kubernetes dashboard service.. thats why i try here as upstream https://kubernetes-dashboard.kubernetes-dashboard.svc.cluster.local.. hope this is right ??

How can I fix this ?? Any Ideas ? Is Keycloak configured correctly ?

Some sites say to use (https://* and http://* as valid urls.. tried without luck)

Hope someone can help.. I did spend a lot time to get this work so far.. but no luck so far.