Just set up a brand new cluster? Changed the domain or IP of your admin node? Then you may have encountered the error Unable to connect to the server: x509: certificate is valid for …. The following is a fix for this common issue. However, there are often other reasons to rebuild your cluster cert, and it’s relatively easy.
TL;DR: “I don’t care about the fix I need to remote control my cluster. Security? Whats that?”:
kubectl --insecure-skip-tls-verify --context=some-context get pods
Let’s say you want to fix the issue and not just skip-tls-verify. Ssh to the admin node and run the following (assuming Kubernetes 1.8 or greater):
# remove the certs rm /etc/kubernetes/pki/apiserver.* # re-create with updated --apiserver-cert-extra-sans kubeadm alpha phase certs all --apiserver-advertise-address=0.0.0.0 --apiserver-cert-extra-sans=new.example.com # remove the kubernetes api server container docker rm -f `docker ps -q -f 'name=k8s_kube-apiserver*'` # restart the kublet systemctl restart kubelet
Port Forwarding / Local Development
Check out kubefwd for a simple command line utility that bulk forwards services of one or more namespaces to your local workstation.
- systemctl - How To Use Systemctl to Manage Systemd Services and Units
- kubeadm - Using kubeadm to Create a Cluster
- Stack Overflow
Kubectl x509 Unable to Connect: Kubernetes remote access and TLS certs. by Craig Johnston is licensed under a Creative Commons Attribution 4.0 International License.