Test Helm chart in CI pipeline

Open points:

• Basic k3d cluster setup
• Move all installation etc. to dedicated builder image

Postponed to later MR:

• Use custom builder image (!283 (merged))
• Create test for running a simple benchmark (unsure if this should be done via helm test as the test pod/job would need a service account etc.), related to #202 (closed) (!285 (merged))
• Add need for deploy-theodolite (#389)

.gitlab-ci.yml

@@ -10,6 +10,7 @@ stages:
   - test
   - check
   - deploy
+  - post-deploy
 
 default:
   tags:
@@ -51,6 +52,34 @@ lint-helm:
     entrypoint: [""]
   script: helm lint helm/
 
+test-helm:
+  stage: post-deploy
+  extends: .dind
+  needs:
+    - lint-helm
+    # - deploy-theodolite
+  variables:
+    KUBECTL: v1.21.3
+    K3D: v4.4.8
+  before_script:
+    - apk add -U wget bash curl
+    # install kubectl
+    - wget -O /usr/local/bin/kubectl https://storage.googleapis.com/kubernetes-release/release/${KUBECTL}/bin/linux/amd64/kubectl
+    - chmod +x /usr/local/bin/kubectl
+    # install k3d
+    - wget -q -O - https://raw.githubusercontent.com/rancher/k3d/${K3D}/install.sh | bash
+    - k3d help
+    - k3d cluster create testgitlabci --agents 1 --wait -p "30000:30000@agent[0]"
+    # show cluster info
+    - kubectl cluster-info
+  script:
+    # Display initial pods, etc.
+    - kubectl get nodes -o wide
+    - kubectl get pods --all-namespaces -o wide
+    - kubectl get services --all-namespaces -o wide
+  after_script:
+    - k3d cluster delete testgitlabci
+
 
 # Theodolite Benchmarks