Kubernetes

Kubernetes Certificate Manager (cert-manager) is a native Kubernetes controller helping you to issue certificates from a variety of sources, such as Let’s Encrypt, HashiCorp Valut, a signing keypair and self-signed. The Certificate Manager ensures certificates are valid and up-to-date, and attempt to renew certificates at a configured time before expiry.

Officially, GitLab doesn’t support RBAC enabled Kubernetes clusters yet, but with some manual configuration, it is possible to integrate your Kubernetes cluster into Gitlab with RBAC enabled.

In Kubernetes it is possible to use Persistent Volumes to add persistent storage to your Docker containers. When creating a Persistent Volume (Claim) you have to configure a storage type and storage capacity. When your application gets successful and your storage exceeds the limits, you have to extend the volume or create a new persistent volume. The latter isn’t a feasible solution in a production environment, but extending a persistent volume isn’t supported out-of-the-box in Kubernetes. There is a solution though! Extending the volume outside Kubernetes!

The last few weeks I’m working with Kubernetes and OpenStack. It’s a steep learning curve to get a production-ready Kubernetes Cluster running on OpenStack, especially because I didn’t want to use the available ready-to-use tools. In the next few blog posts, I want to share my experience how to run Kubernetes on an OpenStack platform.