ci: requiring the 'ok-to-test' label for running some workflows

As of now, the 'e2e-k3s' workflow will require the 'ok-to-test' label in
order to get triggered.

In addition to that, on each change to the PR on the relevant files,
Github will remove the label from it and it will be required again.

Signed-off-by: Yoni Bettan <ybettan@redhat.com>

.github/workflows/e2e-k3s.yaml

@@ -1,7 +1,8 @@
-name: e2e-k8s
+name: e2e-k3s
 
 on:
   pull_request:
+    types: [labeled]
     paths:
       - 'pkg/query-service/**'
       - 'frontend/**'
@@ -10,6 +11,7 @@ jobs:
 
   image-build-and-push-query-service:
     runs-on: ubuntu-latest
+    if: ${{ github.event.label.name == 'ok-to-test' }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
@@ -31,6 +33,7 @@ jobs:
 
   image-build-and-push-frontend:
     runs-on: ubuntu-latest
+    if: ${{ github.event.label.name == 'ok-to-test' }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
@@ -61,6 +64,7 @@ jobs:
 
   deploy-on-k3s-cluster:
     runs-on: ubuntu-latest
+    if: ${{ github.event.label.name == 'ok-to-test' }}
     needs:
       - image-build-and-push-query-service
       - image-build-and-push-frontend

.github/workflows/remove-label.yaml

@@ -0,0 +1,20 @@
+name: remove-label
+
+on:
+  pull_request:
+    types: [synchronize]
+    paths:
+      - 'pkg/query-service/**'
+      - 'frontend/**'
+
+jobs:
+  remove:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Remove label
+        uses: buildsville/add-remove-label@v1
+        with:
+          label: ok-to-test
+          type: remove
+          token: ${{ secrets.REPO_ACCESS_TOKEN }}
+