Added deploy to stage

.gitlab-ci.yml

@@ -1,6 +1,7 @@
 stages:
   - run
   - build
+  - deploy
 
 run_flask_app:
   stage: run
@@ -25,3 +26,21 @@ build_docker_image:
       --dockerfile "$CI_PROJECT_DIR/Dockerfile"
       --destination "$CI_REGISTRY_IMAGE:latest"
       --destination "$CI_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA"
+
+deploy_stage:
+  stage: deploy
+  image:
+    name: bitnami/kubectl:latest
+    entrypoint: [""]
+  before_script:
+    - mkdir -p ~/.kube
+    - echo "$KUBECONFIGCONTENT" > ~/.kube/config
+    - chmod 600 ~/.kube/config
+  script:
+    - kubectl apply -f k8s/stage/
+    - kubectl set image deployment/flask-app flask-app=$CI_REGISTRY_IMAGE:$CI_COMMIT_SHORT_SHA -n stage
+    - kubectl rollout status deployment/flask-app -n stage
+  environment:
+    name: stage
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "main"'