Welcome to Yet Another Useless Blog

GitOps for application deployment and cluster configuration is a must-have I am trying to convince every customer to follow from the very beginning when starting the Kubernetes journey. For me, as more on the infrastructure side of things, I am more focused on the configuration of an environment. Meaning, configuring a cluster, installing an operator etc.

In this article, I would like to share how I deal with cluster configuration when certain Kubernetes objects are dependent on each other and how to use Kubernetes but also Argo CD features to resolve these dependencies.

Finally, after a long time on my backlog, I had some time to look into the Cert-Manager Operator and use this Operator to automatically issue new SSL certificates. This article shall show step-by-step how to create a certificate request and use this certificate for a Route and access a service via your Browser. I will focus on the technical part, using a given domain on AWS Route53.

„If it is not in GitOps, it does not exist“ - However, managing objects partially only by Gitops was always an issue, since ArgoCD would like to manage the whole object. For example, when you tried to work with node labels and would like to manage them via Gitops, you would need to put the whole node object into ArgoCD. This is impractical since the node object is very complex and typically managed by the cluster. There were 3rd party solutions (like the patch operator), that helped with this issue.

However, with the Kubernetes feature Server-Side Apply this problem is solved. Read further to see a working example of this feature.

Sensitive information in OpenShift or Kubernetes is stored as a so-called Secret. The management of these Secrets is one of the most important questions, when it comes to OpenShift. Secrets in Kubernetes are encoded in base64. This is not an encryption format. Even if etcd is encrypted at rest, everybody can decode a given base64 string which is stored in the Secret.

For example: The string Thomas encoded as base64 is VGhvbWFzCg==. This is simply a masked plain text and it is not secure to share these values, especially not on Git. To make your CI/CD pipelines or Gitops process secure, you need to think of a secure way to manage your Secrets. Thus, your Secret objects must be encrypted somehow. HashiCorp Vault is one option to achieve this requirement.

Securing ETCD is one of the major Day-2 tasks for a Kubernetes cluster. This article will explain how to create a backup using OpenShift Cronjob.

Imagine you have one OpenShift cluster and you would like to create 2 or more environments inside this cluster, but also separate them and force the environments to specific nodes, or use specific inbound routers. All this can be achieved using labels, IngressControllers and so on. The following article will guide you to set up dedicated compute nodes for infrastructure, development and test environments as well as the creation of IngressController which are bound to the appropriate nodes.