k8s-oidc-helper
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Helper tool for authenticating to Kubernetes using Google's OpenID Connect
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: [email protected]
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
To merge the new configuration into your existing kubectl config file, run:
$ k8s-oidc-helper -c ./client_secret.json --write
Enter the code Google gave you: <code>
Configuration has been written to ~/.kube/config
# Then you can associate that user to a cluster
$ kubectl config set-context <context-name> --cluster <cluster-name> --user <[email protected]>
$ kubectl config use-context <context-name>
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: [email protected]
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.
--file ~/.kube/config The file to write to. If not specified, ~/.kube/config is used
-o, --open Open the oauth approval URL in the browser (default true)
-v, --version Print version and exit
-w, --write Write config to file. Merges in the specified file
License
MIT License. See License for full text