.credits.md

Credits go to: https://www.methodpark.de/blog/how-to-automate-review-deployments-with-kubernetes-and-gitlab/

.gitlab-ci.yml

# Common base for jobs that deploy to k8s
.deploy-base:
  # For deploying, we need an image that can interact with k8s. Using
  # GitLab's own official image for this should be safe enough:
  image: registry.gitlab.com/gitlab-org/cluster-integration/helm-install-image/releases/2.16.6-kube-1.13.12
  variables:
    # Define k8s namespace and domain used for deployment:
    NS: $CI_COMMIT_REF_SLUG
    CI_ENVIRONMENT_DOMAIN: $CI_COMMIT_REF_SLUG.$KUBE_INGRESS_BASE_DOMAIN
  only:
    # Deploy only branches and tags:
    refs:
      - branches
      - tags
    # Deploy only if k8s integration is configured:
    kubernetes: active


# Job that deploys the app to k8s:
deploy:branch:
  stage: deploy
  extends: .deploy-base
  environment:
    name: $CI_COMMIT_REF_SLUG
    url: http://$CI_COMMIT_REF_SLUG.$KUBE_INGRESS_BASE_DOMAIN
    on_stop: deploy:stop_branch
  before_script:
    - apk add gettext
  script:
    # Create dedicated namespace to deploy in (delete first, if it already exists):
    - kubectl get namespace $NS && kubectl delete namespace $NS || true
    - kubectl create namespace $NS

    # Make Docker credentials available for deployment:
    - kubectl -n $NS create secret docker-registry gitlab-registry --docker-server="$CI_REGISTRY" --docker-username="$CI_REGISTRY_USER" --docker-password="$CI_REGISTRY_PASSWORD"
    - kubectl -n $NS patch serviceaccount default -p '{"imagePullSecrets":[{"name":"gitlab-registry"}]}'

    # Start and expose deployment, set up ingress:
    - kubectl -n $NS create deployment myapp --image=$CI_REGISTRY_IMAGE/$CI_COMMIT_REF_SLUG
    - kubectl -n $NS expose deployment/myapp --type=NodePort --port 3000

    # Set up ingress with env var expansion from template:
    - envsubst < k8s/ingress.yml.tpl | kubectl -n $NS apply -f -

    # Wait for pod
    - kubectl -n $NS wait --for=condition=available deployment/myapp --timeout=180s


# Job that destroys the k8s namespace used to deploy the app. This gets
# triggered either manually or when the environment is stopped (e.g., when an
# MR is merged):
deploy:stop_branch:
  stage: deploy
  extends: .deploy-base
  when: manual
  # This job must not have any dependencies, otherwise it will refuse to run
  # when the artifact retention of previous jobs has expired:
  dependencies: []
  environment:
    name: $CI_COMMIT_REF_SLUG
    action: stop
  variables:
    # Disable checkout here because the ref might not be available anymore
    GIT_STRATEGY: none
  script:
    - kubectl delete namespace $NS

.GitLab.com-to-Kubernetes-Deploy

Summary: How to deploy to Kubernetes using a Gitlab.com managed Kubernetes Cluster