feat: add example and instructions to test knative in airgapped (#932)

* feat: add example and instructions to test knative in airgap

scripts/airgapped/get-all-images.sh

@@ -46,6 +46,9 @@ rm -rf resource-dispatcher
 # manually retrieve pipelines runner image to test pipelines
 IMAGES+=($(echo "charmedkubeflow/pipelines-runner:ckf-1.8"))
 
+# manually retrieve helloworld image to test knative
+IMAGES+=($(echo "ghcr.io/knative/helloworld-go:latest"))
+
 # ensure we only show unique images
 IMAGES=($(echo "${IMAGES[@]}" | tr ' ' '\n' | sort -u | tr '\n' ' '))
 

tests/airgapped/knative/README.md

@@ -0,0 +1,37 @@
+# Testing Knative in airgapped
+
+This directory is dedicated to testing Knative in an airgapped environment.
+
+## Prerequisites
+
+Prepare the airgapped environment and deploy CKF by following the steps in [Airgapped test scripts](https://github.com/canonical/bundle-kubeflow/tree/main/tests/airgapped#testing-airgapped-installation).
+
+Once you run the test scripts, the `knative/helloworld-go` image used in the `helloworld` example will be included in your airgapped environment. It's specifically added in the [`get-all-images.sh` script](../../../scripts/airgapped/get-all-images.sh).
+
+## How to test Knative in an Airgapped environment
+1. Connect to the dashboard by visiting the IP of your airgapped VM. To get the IP run:
+```
+lxc ls | grep eth0
+```
+2. Log in to the dashboard and create a Profile.
+3. Apply the `helloworld.yaml` found in this directory to your Profile's Namespace:
+```
+kubectl apply -f ./helloworld.yaml -n <your namespace>
+```
+4. Wait for the Knative Service to be `Ready`
+```
+kubectl get ksvc -n <your namespace>
+```
+Expected output:
+```
+NAME         URL                                           LATESTCREATED      LATESTREADY        READY   REASON
+helloworld   http://helloworld.admin.10.64.140.43.nip.io   helloworld-00001   helloworld-00001   True    
+```
+5. Curl the Knative Service using the `URL` from the previous step
+```
+curl -L http://helloworld.admin.10.64.140.43.nip.io
+```
+Expected output:
+```
+Hello World!
+```

tests/airgapped/knative/helloworld.yaml

@@ -0,0 +1,19 @@
+# This example is based on the [Knative Serving tutorial](https://knative.dev/docs/getting-started/first-service/#__tabbed_1_2)
+apiVersion: serving.knative.dev/v1
+kind: Service
+metadata:
+  name: hello
+spec:
+  template:
+    metadata:
+      labels:
+        # Disable istio sidecar due to https://github.com/canonical/kserve-operators/issues/216
+        sidecar.istio.io/inject	: "false"
+    spec:
+      containers:
+        - image: 172.17.0.2:5000/knative/helloworld-go:latest
+          ports:
+            - containerPort: 8080
+          env:
+            - name: TARGET
+              value: "World"