OpenShift

In this blog post we would like to explore OpenShift / Kubernetes block device handling. We try to answer the following questions:

This quick post shall explain, without any fancy details, how to write an Operator based on Ansible. It is assumed that you know what purpose an Operator has.

As a short summary: Operators are a way to create custom controllers in OpenShift or Kubernetes. It watches for custom resource objects and creates the application based on the parameters in such custom resource object. Often written in Go, the SDK supports Ansible, Helm and (new) Java as well.

OpenShift comes per default with a static Grafana dashboard, which will present cluster metrics to cluster administrators. It is not possible to customize this Grafana instance.

However, many customers would like to create their own dashboards, their own monitoring and their own alerting while leveraging the possibilities of OpenShift at the same time and without installing a completely separated monitoring stack.

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. GitOps itself uses Git pull request to manager infrastructure and application configuration.

Red Hat Service Mesh 1.1 allows you to enable a "Automatic Route Creation" which will take care about the routes for a specific Gateway. Instead of defining * for hosts, a list of domains can be defined. The Istio OpenShift Routing (ior) synchronizes the routes and creates them inside the Istio namespace. If a Gateway is deleted, the routes will also be removed again.

This new features makes the manual creation of the route obsolete, as it was explained here: Openshift 4 and Service Mesh 4 - Ingress with custom domain

Red Hat Quay is an enterprise-quality container registry, which is responsible to build, scan, store and deploy containers. The main features of Quay include:

and much more.

Per default all requests inside a Service Mesh are allowed, which can be a problem security-wise. To solve this, authorization, which verifies if the user is allowed to perform a certain action, is required. Istio’s authorization provides access control on mesh-level, namespace-level and workload-level.

To test a second application, a bookinfo application shall be deployed as an example.

The following section finds it’s origin at: