2 min read | by Jordi Prats
The configuration file kubeconfig (~/.kube/config) is used to get access to a Kubernetes cluster. It looks like a Kubernetes object that defines the cluster, the user and the context to use:
apiVersion: v1 kind: Config preferences: {} clusters: (...) users: (...) contexts: (...) Let's take a minikube kubeconfig as an example
On the clusters section we are defining how to connect to the cluster:
apiVersion: v1 clusters: - cluster: certificate-authority: /home/pet2cattle/.minikube/ca.crt extensions: - extension: last-update: Wed, 23 Jun 2021 08:27:49 CEST provider: minikube.sigs.k8s.io version: v1.20.0 name: cluster_info server: https://192.168.49.2:8443 name: minikube (...) On the users section we are telling kubectl how to identify itself using SSL certificates:
apiVersion: v1 kind: Config users: - name: minikube user: client-certificate: /home/pet2cattle/.minikube/profiles/minikube/client.crt client-key: /home/pet2cattle/.minikube/profiles/minikube/client.key (...) Finally, the contexts section is the glue between the other sections telling which user to use to connect to which cluster. We can also fins which is the default namespace to use:
apiVersion: v1 kind: Config contexts: - context: cluster: minikube extensions: - extension: last-update: Wed, 23 Jun 2021 08:27:49 CEST provider: minikube.sigs.k8s.io version: v1.20.0 name: context_info namespace: default user: minikube name: minikube (...) There's also the current-context which tell us which is context is currently in use. A complete example would be:
apiVersion: v1 current-context: minikube kind: Config preferences: {} clusters: - cluster: certificate-authority: /home/pet2cattle/.minikube/ca.crt extensions: - extension: last-update: Wed, 23 Jun 2021 08:27:49 CEST provider: minikube.sigs.k8s.io version: v1.20.0 name: cluster_info server: https://192.168.49.2:8443 name: minikube contexts: - context: cluster: minikube extensions: - extension: last-update: Wed, 23 Jun 2021 08:27:49 CEST provider: minikube.sigs.k8s.io version: v1.20.0 name: context_info namespace: default user: minikube name: minikube users: - name: minikube user: client-certificate: /home/pet2cattle/.minikube/profiles/minikube/client.crt client-key: /home/pet2cattle/.minikube/profiles/minikube/client.key So, if we have two cluster with two different kubeconfig files we can create a new one with both clusters copying the three sections (users, clusters and contexts) and making sure it's names don't collide between them
Posted on 29/06/2021