OIDC with Kong Ingress Controller

TL;DR

Create a KongPlugin instance containing your client_id, client_secret, and grant_type, then annotate a Service or Route with konghq.com/plugins=my-oidc-plugin.

Prerequisites

If you don’t have a Konnect account, you can get started quickly with our onboarding wizard.

  1. The following Konnect items are required to complete this tutorial:
    • Personal access token (PAT): Create a new personal access token by opening the Konnect PAT page and selecting Generate Token.
  2. Set the personal access token as an environment variable:

    export KONNECT_TOKEN='YOUR KONNECT TOKEN'
    
    Copied to clipboard!

About OpenID Connect

Kong Gateway Enterprise’s OIDC plugin can authenticate requests using the OpenID Connect protocol. Learn how to set up the OIDC plugin using the Kong Ingress Controller.

Deploy Keycloak

This how-to uses Keycloak as an OpenID Connect provider.

Install Keycloak

kubectl apply -f https://raw.githubusercontent.com/keycloak/keycloak-quickstarts/refs/heads/main/kubernetes/keycloak.yaml -n kong
Copied to clipboard!

Create a Route

We’ll use Kong Gateway to expose Keycloak in our cluster on a custom domain:

Register a client and user

Set two variables containing your client ID and secret:

export CLIENT_ID=kong
export CLIENT_SECRET=this_is_sup3r_secret
Copied to clipboard!

To call the Keycloak admin API, fetch an access token using the password grant type:

You may need to wait for Keycloak to be deployed before calling the API. Run kubectl get pods -n kong and wait until the Keycloak pod is ready.

ACCESS_TOKEN=$(curl -sSk -X POST "https://keycloak.$PROXY_IP.nip.io/realms/master/protocol/openid-connect/token" \
     -d client_id="admin-cli" -d username=admin -d password=admin -d grant_type=password | jq -r .access_token)
Copied to clipboard!

Next, create a new openid-connect client:

curl -k -X POST "https://https://keycloak.$PROXY_IP.nip.io/admin/realms/master/clients" \
     -H "Authorization: Bearer $ACCESS_TOKEN" \
     --json '{
       "protocol": "openid-connect",
       "clientId": "'$CLIENT_ID'",
       "secret": "'$CLIENT_SECRET'",
       "standardFlowEnabled": true,
       "redirectUris": [
         "http://'$PROXY_IP'/*"
       ]
     }'
Copied to clipboard!

Finally, register a user named alex with the password password:

curl -k -X POST "https://https://keycloak.$PROXY_IP.nip.io/admin/realms/master/users" \
     -H "Authorization: Bearer $ACCESS_TOKEN" \
     --json '{
       "username": "alex",
       "enabled": true,
       "credentials": [
         {
           "type": "password",
           "value": "password",
           "temporary": false
         }
       ]
     }'
Copied to clipboard!

You are now ready to configure the OpenID Connect plugin

Configure the OpenID Connect plugin

This example uses keycloak.$PROXY_IP.nip.io as the host, but you can use any domain name of your choice. For demo purposes, you can use the nip.io service to avoid setting up a DNS record.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: openid-connect
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
config:
  issuer: https://keycloak.$PROXY_IP.nip.io/realms/master
  client_id:
  - '$CLIENT_ID'
  client_secret:
  - '$CLIENT_SECRET'
  redirect_uri:
  - http://$PROXY_IP/echo
plugin: openid-connect
" | kubectl apply -f -
Copied to clipboard!

Next, apply the KongPlugin resource by annotating the service resource:

kubectl annotate -n kong service echo konghq.com/plugins=openid-connect
Copied to clipboard!

Validate your configuration

Once the resource has been reconciled, you’ll be able to call the /echo endpoint and Kong Gateway will route the request to the echo Service.

If you make a request without any authentication credentials, the request will fail with an HTTP 302 and a redirect to the Keycloak login page:

curl -i "$PROXY_IP/echo"
Copied to clipboard!

If you provide a password the request will be proxied successfully:

curl "$PROXY_IP/echo" \
     -u alex:password
Copied to clipboard!

Cleanup

kubectl delete -n kong -f https://developer.konghq.com/manifests/kic/echo-service.yaml
Copied to clipboard!

Did this doc help?

Something wrong?

Help us make these docs great!

Kong Developer docs are open source. If you find these useful and want to make them better, contribute today!