How to manage multiple GKE projects in one Google Cloud Account

Given a situation where I have three separate GKE instances in different Google Cloud projects under the same billing account, how can I configure kubectl so that the commands I execute with it only apply to a specific cluster?

Solution

kubectl access to Kubernetes API servers are managed by configuration contexts.

Here is some documentation for how to do so. In a nutshell, you would stand up multiple Kubernetes clusters and then specify a configuration like so:

apiVersion: v1
kind: Config
preferences: {}

clusters:
- cluster:
  name: development
- cluster:
  name: scratch

users:
- name: developer
- name: experimenter

contexts:
- context:
  name: dev-frontend
- context:
  name: dev-storage
- context:
  name: exp-scratch

To automatically generate one, you can run the following commands:

# Add cluster details to the file
kubectl config --kubeconfig=config-demo set-cluster development --server=https://1.2.3.4 --certificate-authority=fake-ca-file

kubectl config --kubeconfig=config-demo set-cluster scratch --server=https://5.6.7.8 --insecure-skip-tls-verify


# Add user details to the configuration file
kubectl config --kubeconfig=config-demo set-credentials developer --client-certificate=fake-cert-file --client-key=fake-key-seefile

kubectl config --kubeconfig=config-demo set-credentials experimenter --username=exp --password=some-password


# Add context details to the configuration file
kubectl config --kubeconfig=config-demo set-context dev-frontend --cluster=development --namespace=frontend --user=developer

kubectl config --kubeconfig=config-demo set-context dev-storage --cluster=development --namespace=storage --user=developer

kubectl config --kubeconfig=config-demo set-context exp-scratch --cluster=scratch --namespace=default --user=experimenter

After that, you can safe the context. Then, going forward, when you run a kubectl command, the action will apply to the cluster and namespace listed in the specifeid context. For example:

kubectl config --kubeconfig=config-demo use-context dev-frontend

To then change the context to another one you specified:

kubectl config --kubeconfig=config-demo use-context exp-scratch