Deploy Test Apps

Now that we havwe defined our contraint templates and deployed some contraints, let’s see if they work!

Test image repos in prod namespace

Earlier we define that all pods in the production namespace must only use images from xxxx repo. Let’s deploy a pod using a different unauthorized repo.

Here’s an example:

apiVersion: v1
kind: Pod
metadata:
  name: opa
  namespace: production
  labels:
    owner: me.agilebank.demo
spec:
  containers:
    - name: opa
      image: openpolicyagent/opa:0.9.2
      args:
        - "run"
        - "--server"
        - "--addr=localhost:8080"
      resources:
        limits:
          cpu: "100m"
          memory: "30Mi"

Let’s add this to our git repo

mkdir example-apps

curl https://weaveworks-gitops.awsworkshop.io/30_workshop_03_grc/deploy.files/pod-unauthorized-repo-example.yaml -o example-apps/pod-unauthorized-repo.yaml

git add example-apps/pod-unauthorized-repo.yaml

git commit -m "adding pod to test allowed repos"

git push

Check what happened to the pod, run the following:

kubectl get pods opa -n production

You should see it does not get deployed.

If we explore flux logs we should be able to see what happened and get the following error:

Error from server ([denied by prod-repo-is-openpolicyagent] container  has an invalid image repo , allowed repos are ["only-this-repo"]): error when creating "pod-unauthorized-repo.yaml": admission webhook "validation.gatekeeper.sh" denied the request: [denied by prod-repo-is-openpolicyagent] container  has an invalid image repo , allowed repos are ["only-this-repo"]

To get the logs run:

kubectl logs <flux-pod> -n fluxcd

If you run the following command you will get the same error:

kubectl create -f ./example-apps/pod-unauthorized-repo.yaml

Lets test namespaces

Download this manifest and try to create this namespace:

mkdir namespaces
curl https://weaveworks-gitops.awsworkshop.io/30_workshop_03_grc/deploy.files/bad-namespace-example.yaml -o namespaces/bad-namespace.yaml

It should look like this:

apiVersion: v1
kind: Namespace
metadata:
  name: test-namespace

Lets run this manually for now so we can see it fail:

kubectl create -f ./namespaces/bad-namespace.yaml
Error from server ([denied by all-must-have-owner] All namespaces must have an `owner` label that points to your company username): error when creating "bad-namespace.yaml": admission webhook "validation.gatekeeper.sh" denied the request: [denied by all-must-have-owner] All namespaces must have an `owner` label that points to your company username

Let’s make sure our policy allows namespaces to be created when the rules are met. Edit the manifest with the following:

apiVersion: v1
kind: Namespace
metadata:
  name: test-namespace
  labels:
    owner: testuser.agilebank.demo

Now let’s check this in to git:

git add "namespaces/bad-namespace.yaml"

git commit -m "fixing bad namespace with label"

git push

You see that this has nwo been created.

namespace/test-namespace created

Summary

We’ve proven now that the policies we’ve defined through OPA Gatekeeper Contraint templates have worked.

  • We created contraint templates which then created our contraint crds K8sAllowedRepos and K8sRequiredLabels.

  • This allowed us to declaritively created K8sAllowedRepos and K8sRequiredLabels objects and parameterise them. We can create more adn add different values and point to different namespaces or even different resources such as services, secrets etc