117 lines
3.7 KiB
Markdown
117 lines
3.7 KiB
Markdown
---
|
|
title: Configure the Pinniped Concierge to validate webhook tokens
|
|
description: Set up webhook-based token authentication on an individual Kubernetes cluster.
|
|
cascade:
|
|
layout: docs
|
|
menu:
|
|
docs:
|
|
name: Configure Concierge Webhook Authentication
|
|
weight: 40
|
|
parent: howtos
|
|
---
|
|
|
|
The Concierge can validate arbitrary tokens via an external webhook endpoint using the [same validation process as Kubernetes itself](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#webhook-token-authentication).
|
|
|
|
## Prerequisites
|
|
|
|
Before starting, you should have the [command-line tool installed]({{< ref "install-cli" >}}) locally and [Concierge running in your cluster]({{< ref "install-concierge" >}}).
|
|
|
|
You should also have a custom TokenReview webhook endpoint:
|
|
|
|
- Your webhook endpoint must handle the `authentication.k8s.io/v1` [TokenReview API](https://kubernetes.io/docs/reference/kubernetes-api/authentication-resources/token-review-v1/#TokenReview).
|
|
|
|
- Your webhook must be accessible from the Concierge pod over HTTPS.
|
|
|
|
## Create a WebhookAuthenticator
|
|
|
|
Create a WebhookAuthenticator describing how to validate tokens using your webhook:
|
|
|
|
```yaml
|
|
apiVersion: authentication.concierge.pinniped.dev/v1alpha1
|
|
kind: WebhookAuthenticator
|
|
metadata:
|
|
name: my-webhook-authenticator
|
|
spec:
|
|
# HTTPS endpoint to be called as a webhook
|
|
endpoint: https://my-webhook.example.com/any/path
|
|
tls:
|
|
# base64-encoded PEM CA bundle (optional)
|
|
certificateAuthorityData: "LS0tLS1CRUdJTi[...]"
|
|
```
|
|
|
|
If you've saved this into a file `my-webhook-authenticator.yaml`, then install it into your cluster using:
|
|
|
|
```sh
|
|
kubectl apply -f my-webhook-authenticator.yaml
|
|
```
|
|
|
|
## Generate a kubeconfig file
|
|
|
|
Generate a kubeconfig file to target the WebhookAuthenticator:
|
|
|
|
```sh
|
|
pinniped get kubeconfig \
|
|
--static-token-env MY_CLUSTER_ACCESS_TOKEN \
|
|
> my-cluster.yaml
|
|
```
|
|
|
|
This creates a kubeconfig YAML file `my-cluster.yaml` that targets your WebhookAuthenticator using `pinniped login static` as an [ExecCredential plugin](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#client-go-credential-plugins).
|
|
|
|
It should look something like below:
|
|
|
|
```yaml
|
|
apiVersion: v1
|
|
kind: Config
|
|
current-context: pinniped
|
|
clusters:
|
|
- cluster:
|
|
certificate-authority-data: LS0tLS[...]
|
|
server: https://my-kubernetes-api-endpoint.example.com:59986
|
|
name: pinniped
|
|
contexts:
|
|
- context:
|
|
cluster: pinniped
|
|
user: pinniped
|
|
name: pinniped
|
|
users:
|
|
- name: pinniped
|
|
user:
|
|
exec:
|
|
apiVersion: client.authentication.k8s.io/v1beta1
|
|
command: /usr/local/bin/pinniped
|
|
args:
|
|
- login
|
|
- oidc
|
|
- login
|
|
- static
|
|
- --enable-concierge
|
|
- --concierge-api-group-suffix=pinniped.dev
|
|
- --concierge-authenticator-name=my-webhook-authenticator
|
|
- --concierge-authenticator-type=webhook
|
|
- --concierge-endpoint=https://127.0.0.1:59986
|
|
- --concierge-ca-bundle-data=LS0tLS[...]
|
|
- --token-env=MY_CLUSTER_ACCESS_TOKEN
|
|
```
|
|
|
|
## Use the kubeconfig file
|
|
|
|
Set the `$MY_CLUSTER_ACCESS_TOKEN` environment variable and use the kubeconfig with `kubectl` to access your cluster:
|
|
|
|
```sh
|
|
MY_CLUSTER_ACCESS_TOKEN=secret-token kubectl --kubeconfig my-cluster.yaml get namespaces
|
|
```
|
|
|
|
You should see:
|
|
|
|
- The `pinniped login static` command is silently executed automatically by `kubectl`.
|
|
|
|
- The command-line tool sends your token to the Concierge which validates it by making a request to your webhook endpoint.
|
|
|
|
- In your shell, you see your clusters namespaces.
|
|
|
|
If instead you get an access denied error, you may need to create a ClusterRoleBinding for the username/groups returned by your webhook, for example:
|
|
|
|
```sh
|
|
kubectl create clusterrolebinding my-user-admin --clusterrole edit --user my-username
|
|
```
|