Configure OpenID Connect with refresh token

Uses: Kong Gateway decK

Deployment Platform:

Prerequisites

Kong Konnect

This is a Konnect tutorial and requires a Konnect personal access token.

Create a new personal access token by opening the Konnect PAT page and selecting Generate Token.
Export your token to an environment variable:
```
 export KONNECT_TOKEN='YOUR_KONNECT_PAT'
```
Run the quickstart script to automatically provision a Control Plane and Data Plane, and configure your environment:
```
 curl -Ls https://get.konghq.com/quickstart | bash -s -- -k $KONNECT_TOKEN --deck-output
```
This sets up a Konnect Control Plane named quickstart, provisions a local Data Plane, and prints out the following environment variable exports:
```
 export DECK_KONNECT_TOKEN=$KONNECT_TOKEN
 export DECK_KONNECT_CONTROL_PLANE_NAME=quickstart
 export KONNECT_CONTROL_PLANE_URL=https://us.api.konghq.com
 export KONNECT_PROXY_URL='http://localhost:8000'
```
Copy and paste these into your terminal to configure your session.

Kong Gateway running

This tutorial requires Kong Gateway Enterprise. If you don’t have Kong Gateway set up yet, you can use the quickstart script with an enterprise license to get an instance of Kong Gateway running almost instantly.

Export your license to an environment variable:

 export KONG_LICENSE_DATA='LICENSE-CONTENTS-GO-HERE'

Run the quickstart script:

 curl -Ls https://get.konghq.com/quickstart | bash -s -- -e KONG_LICENSE_DATA 

Once Kong Gateway is ready, you will see the following message:

 Kong Gateway Ready

decK

decK is a CLI tool for managing Kong Gateway declaratively with state files. To complete this tutorial you will first need to install decK.

Required entities

For this tutorial, you’ll need Kong Gateway entities, like Gateway Services and Routes, pre-configured. These entities are essential for Kong Gateway to function but installing them isn’t the focus of this guide. Follow these steps to pre-configure them:

Run the following command:

echo '
_format_version: "3.0"
services:
  - name: example-service
    url: http://httpbin.konghq.com/anything
routes:
  - name: example-route
    paths:
    - "/anything"
    service:
      name: example-service
' | deck gateway apply -

To learn more about entities, you can read our entities documentation.

Set up Keycloak

This tutorial requires an identity provider (IdP). If you don’t have one, you can use Keycloak. The steps will be similar in other standard identity providers.

Create a client

Install Keycloak (version 26 or later) on your platform.

For example, you can use the Keycloak Docker image:

 docker run -p 8080:8080 \
   -e KC_BOOTSTRAP_ADMIN_USERNAME=admin \
   -e KC_BOOTSTRAP_ADMIN_PASSWORD=admin \
   quay.io/keycloak/keycloak start-dev

Open the admin console.

The default URL of the console is http://$YOUR_KEYCLOAK_HOST:8080/admin/master/console/.
In the sidebar, open Clients, then click Create client.
Configure the client:

Section	Settings
General settings	Client type: OpenID Connect Client ID: any unique name, for example `kong`
Capability config	Toggle Client authentication to on Make sure that Standard flow, Direct access grants, and Service accounts roles are checked.
Login settings	Valid redirect URIs: `http://localhost:8000/*`

Set up keys and credentials

In your client, open the Credentials tab.
Set Client Authenticator to Client ID and Secret.
Copy the Client Secret.
Switch to the Users menu and add a user.
Open the user’s Credentials tab and add a password. Be sure to disable Temporary Password.

In this guide, we’re going to use an example user named alex with the password doe.

Export to environment variables

Export your client secret, client ID, and issuer URL to environment variables so that you can pass them more securely. For example:

export DECK_ISSUER=http://host.docker.internal:8080/realms/master
export DECK_CLIENT_ID=kong
export DECK_CLIENT_SECRET=UNT3GPzCKI7zUbhAmFSUGbj4wmiBDGiW

Enable the OpenID Connect plugin with refresh tokens

Using the Keycloak and Kong Gateway configuration from the prerequisites, set up an instance of the OpenID Connect plugin with the refresh token grant.

We’re also enabling the password grant, as well as a refresh token header, so that we can test retrieving the token.

Enable the OpenID Connect plugin on the example-service Service:

echo '
_format_version: "3.0"
plugins:
  - name: openid-connect
    service: example-service
    config:
      issuer: "${{ env "DECK_ISSUER" }}"
      client_id:
      - "${{ env "DECK_CLIENT_ID" }}"
      client_secret:
      - "${{ env "DECK_CLIENT_SECRET" }}"
      client_auth:
      - client_secret_post
      auth_methods:
      - refresh_token
      - password
      refresh_token_param_type:
      - header
      refresh_token_param_name: refresh_token
      upstream_refresh_token_header: refresh_token
' | deck gateway apply -

In this example:

issuer, client ID, client secret, and client auth: Settings that connect the plugin to your IdP (in this case, the sample Keycloak app).
auth_methods: Specifies that the plugin should use the refresh token auth flow and the password grant for authentication.
refresh_token_param_type: Restricts refresh token lookup to request headers only.

Note: Setting config.client_auth to client_secret_post lets you easily test the connection to your IdP, but we recommend using a more secure auth method in production. You can use any of the supported client auth methods.

Retrieve the refresh token

Check that you can recover the refresh token by requesting the Service with the basic authentication credentials created in the prerequisites:

curl -i -X GET "$KONNECT_PROXY_URL/anything" \
     -u alex:doe

curl -i -X GET "http://localhost:8000/anything" \
     -u alex:doe

You should see a Refresh-Token header in the response.

Export the token to an environment variable:

export REFRESH_TOKEN='{your-refresh-token}'

Validate the refresh token grant

Now, validate the setup by accessing the example-route Route and passing the refresh token in a Refresh-Token header:

curl -i -X GET "$KONNECT_PROXY_URL/anything" \
     -H "Refresh-Token: $REFRESH_TOKEN"

curl -i -X GET "http://localhost:8000/anything" \
     -H "Refresh-Token: $REFRESH_TOKEN"

If Kong Gateway successfully authenticates with Keycloak, you’ll see a 200 response with your bearer token in the Authorization header.

If you make another request using the same credentials, you’ll see that Kong Gateway adds less latency to the request because it has cached the token endpoint call to Keycloak:

X-Kong-Proxy-Latency: 25

Alternatively, you can use jq to pass the credentials and retrieve the most recent refresh token every time:

curl -i -X GET "$KONNECT_PROXY_URL/anything" \
     -H "Refresh-Token:$(curl --user alex:doe http://localhost:8000/anything \
        | jq -r '.headers."Refresh-Token"')
"

curl -i -X GET "http://localhost:8000/anything" \
     -H "Refresh-Token:$(curl --user alex:doe http://localhost:8000/anything \
        | jq -r '.headers."Refresh-Token"')
"

Cleanup

Clean up Konnect environment

If you created a new control plane and want to conserve your free trial credits or avoid unnecessary charges, delete the new control plane used in this tutorial.

Destroy the Kong Gateway container

curl -Ls https://get.konghq.com/quickstart | bash -s -- -d