env-route-ns-mutator

README

env-route-ns-mutator

This project implements a Kubernetes admission webhook that mutates Namespace objects and Route objects in OpenShift. It does so based on the environment the Namespace or the Route is a part of.

The list of respected environments is set by the environments env var set on the manager deployment.

Namespace Mutator

The mutator adds an environment: <ENV> label to every Namespace that has the defaultTolerations annotation that matches the specific environment:

apiVersion: v1
kind: Namespace
metadata:
  name: test-ns
  labels: {} # original
  annotations:
    scheduler.alpha.kubernetes.io/defaultTolerations: "[{"operator": "Exists", "effect": "NoSchedule", "key": "<ENV>"}]"

apiVersion: v1
kind: Namespace
metadata:
  name: test-ns
  labels:
    environment: <ENV> # mutated
  annotations:
    scheduler.alpha.kubernetes.io/defaultTolerations: "[{"operator": "Exists", "effect": "NoSchedule", "key": "<ENV>"}]"

Route Mutator

The mutator changes the host field of the Route based on the environment: <ENV> label on the namespace the Route exists in.

For example, it would change the apps part of the Route to be <ENV>-apps.

Empty Host

kind: Route
apiVersion: route.openshift.io/v1
metadata:
  name: route-test
  namespace: test-ns
spec:
  host: "" # (original)

kind: Route
apiVersion: route.openshift.io/v1
metadata:
  name: route-test
  namespace: test-ns
spec:
  host: "route-test-test-ns.<ENV>-apps.cluster-name.example.dom" # (mutated)

Host with Cluster Ingress Domain

kind: Route
apiVersion: route.openshift.io/v1
metadata:
  name: route-test
  namespace: test-ns
spec:
  host: "test.apps.cluster-name.example.dom" # (original)

kind: Route
apiVersion: route.openshift.io/v1
metadata:
  name: route-test
  namespace: test-ns
spec:
  host: "test.<ENV>-apps.cluster-name.example.dom" # (mutated)

Getting started

Deploying the controller

$ make deploy IMG=ghcr.io/dana-team/env-route-ns-mutator:<release>

Install with Helm

Helm chart docs are available on charts/env-route-ns-mutator directory.

Make sure cert-manager is installed as a prerequisite.

$ helm upgrade --install env-route-ns-mutator --namespace env-route-ns-mutator-system --create-namespace oci://ghcr.io/dana-team/helm-charts/env-route-ns-mutator --version <release>

Build your own image

$ make docker-build docker-push IMG=<registry>/env-route-ns-mutator:<tag>