Setup Single Sign-On of Harbor with Opstella

Prerequisites

To Setup Single Sign-On with Opstella, you need

• 📦Opstella Keycloak
  • While you reading this section and have not yet setup Opstella Keycloak, you can skip its consideration for now.
  • Your dedicated Keycloak Realm. ${KEYCLOAK_REALM} ; Please change accordingly
• 🔑OpenID Connect Credentials: Client ID, Client Secret.
  • Gather Client ID, Client Secret - from Opstella Keycloak Appendix - Gathering Client ID, Client Secret

Harbor with Opstella Single Sign-On Integration

You need to go to Harbor instance that you have installed and configure within its settings menu.

1. Gather 🔑OpenID Connect Credentials (Client ID, Client Secret)

2. Go to ${HARBOR_DOMAIN} and Login with Initial Admin Account

3. Go to Administration > Configuration > Authentication

   Configure by adjust/fill in the textfield follow by the list:

   💡 Your dedicated Keycloak Realm. ${KEYCLOAK_REALM} ; Please change accordingly

   • Auth Mode: OIDC

   • OIDC Provider Name: OPSTELLA (ALL CAPS)

   • OIDC Endpoint: https://${KEYCLOAK_DOMAIN}/realms/${KEYCLOAK_REALM}

   • OIDC Client ID: CHANGEME 🔑

   • OIDC Client Secret: CHANGEME 🔑

   • Group Claim Name: groups

   • OIDC Scope: openid,profile,email

   • Verify Certificate: ✅ Yes (Ticked)

     Untick this while the Identity Provider uses a private certificate

     Harbor validates the Keycloak certificate on its own back-channel call. If that certificate is not issued by a publicly trusted CA — a self-signed or internal-CA certificate, common before the real one is installed — TEST OIDC SERVER fails and login is rejected.

     Untick it (oidc_verify_cert: false over the API) to proceed, and tick it again once the production certificate is in place. Unlike the other components, Harbor offers no way to supply a CA bundle here.

   • Automatic onboarding: ✅ Yes (Ticked)

   • Username Claim: preferred_username

4. Click on TEST OIDC SERVER and it should inform Connection to OIDC server is verified

   

5. Click Save

   Testing Single Sign-On Integration in End-to-End Testing/Single Sign-On for Harbor

Configure the same settings over the API

The screenshots above are the only documented path, but the whole configuration is one API call. Use this when the Harbor UI is not reachable, or to script the configuration.

kubectl port-forward --namespace registry-system svc/harbor-core 18080:80 &

curl -s -o /dev/null -w "%{http_code}\n" -u "admin:${HARBOR_ADMIN_PASSWORD}" \
  -X PUT "http://127.0.0.1:18080/api/v2.0/configurations" \
  -H "Content-Type: application/json" -d @- <<JSON
{
  "auth_mode": "oidc_auth",
  "oidc_name": "OPSTELLA",
  "oidc_endpoint": "https://${KEYCLOAK_DOMAIN}/realms/${KEYCLOAK_REALM}",
  "oidc_client_id": "${HARBOR_OIDC_CLIENT_ID}",
  "oidc_client_secret": "${HARBOR_OIDC_CLIENT_SECRET}",
  "oidc_groups_claim": "groups",
  "oidc_scope": "openid,profile,email",
  "oidc_verify_cert": true,
  "oidc_auto_onboard": true,
  "oidc_user_claim": "preferred_username"
}
JSON

💡 Returns 200. Verify with:

curl -s -u "admin:${HARBOR_ADMIN_PASSWORD}" \
  "http://127.0.0.1:18080/api/v2.0/systeminfo" | jq '{auth_mode, harbor_version}'