k8s-oidc-helper

This is a small helper tool to get a user get authenticated with Kubernetes OIDC using Google as the Identity Provider.

Given a ClientID and ClientSecret, the tool will output the necessary configuration for kubectl that you can add to ~/.kube/config

$ k8s-oidc-helper -c ./client_secret.json
Enter the code Google gave you: <code>

# Add the following to your ~/.kube/config
users:
- name: you@yourdomain.com
  user:
    auth-provider:
      config:
        client-id: <client-id>
        client-secret: <client-secret>
        id-token: <id-token>
        idp-issuer-url: https://accounts.google.com
        refresh-token: <refresh-token>
      name: oidc

Setup

There is a bit of setup involved before you can use this tool.

First, you'll need to create a project and OAuth 2.0 Credential in the Google Cloud Console. You can follow this guide on creating an application, but do NOT create a web application. You'll need to select "Other" as the Application Type. Once that is created, you can download the ClientID and ClientSecret as a JSON file for ease of use.

Second, your kube-apiserver will need the following flags on to use OpenID Connect.

--oidc-issuer-url=https://accounts.google.com \
--oidc-username-claim=email \
--oidc-client-id=<Your client ID>\

Role-Based Access Control

If you are using RBAC as your --authorization-mode, you can use the following ClusterRole and ClusterRoleBinding for administrators that need cluster-wide access.

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1alpha1
metadata:
  name: admin-role
rules:
- apiGroups: ["*"]
  resources: ["*"]
  verbs: ["*"]
  nonResourceURLs: ["*"]
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1alpha1
metadata:
  name: admin-binding
subjects:
- kind: User
  name: you@yourdomain.com
roleRef:
  kind: ClusterRole
  name: admin-role

Installation

go get github.com/micahhausler/k8s-oidc-helper

Usage

Usage of k8s-oidc-helper:

  --client-id string
        The ClientID for the application
  --client-secret string
        The ClientSecret for the application
  -c, --config string
        Path to a json file containing your application's ClientID and ClientSecret. Supercedes the --client-id and --client-secret flags.
  -o, --open true
        Open the oauth approval URL in the browser. Defaults to true (default true)
  -v, --version
        print version and exit

Wishlist

• Add tests/CI
• Add docker builds to CI

License

MIT License. See License for full text