micro-application-admission

README

MicroApplication Mutating Webhook

When a new MicroApplication is created, this webhook mutates the object to add/update the creator of the resource in an annotation.

apiVersion: argoproj.io/v1alpha1
kind: MicroApplication
metadata:
  annotations:
    foo: bar
    generated-creator: 'kube:admin'

Install

1. Create the MicroApplication CRD

$ kubectl apply -f https://github.com/sbose78/micro-application/blob/main/config/crd/bases/argoproj.io_microapplications.yaml

1. Create the namespace and install the webhook.

On OpenShift,

$ kubectl apply -f https://github.com/sbose78/micro-application-admission/blob/main/manifests/openshift/install.yaml

On other distributions of Kubernetes,

$ kubectl apply -f https://github.com/sbose78/micro-application-admission/blob/main/manifests/kubernetes/install.yaml

Verify

1. The webhook-server pod in the microapplication-webhook namespace should be running:

$ kubectl -n microapplication-webhook get pods
NAME                             READY     STATUS    RESTARTS   AGE
webhook-server-6f976f7bf-hssc9   1/1       Running   0          35m

1. A MutatingWebhookConfiguration named microapplication-webhook should exist:

$ kubectl get mutatingwebhookconfigurations
NAME           AGE
microapplication-webhook   36m

1. Create a MicroApplication

apiVersion: argoproj.io/v1alpha1
kind: MicroApplication
metadata:
  annotations:
    foo: bar
    generated-creator: 'kube:admin'
  name: example
  namespace: any-namespace
spec:
  repoURL: https://github.com/sbose78/gitops-samples
  path: developer/new-app

Fetch the recently created MicroApplication named example in namespace any-namespace. Notice that the annotation generated-creator has been filled in.

apiVersion: argoproj.io/v1alpha1
kind: MicroApplication
metadata:
  annotations:
    foo: bar
    generated-creator: 'john'
  name: example
  namespace: any-namespace
spec:
  repoURL: https://github.com/sbose78/gitops-samples
  path: developer/new-app

Build the Image from Sources (optional)

An image can be built by running make. If you want to modify the webhook server for testing purposes, be sure to set and export the shell environment variable IMAGE to an image tag for which you have push access. You can then build and push the image by running make push-image. Also make sure to change the image tag in deployment/deployment.yaml.template, and if necessary, add image pull secrets.

Credits

This code is based on https://github.com/stackrox/admission-controller-webhook-demo