.gitlab-ci.yaml

services:
  - docker:18.09.9-dind

cache:
  paths:
    - .m2/repository

before_script:
  - source ci/script.sh

variables:
  VARIABLES_FILE: ./variables.txt
  DOCKER_API_VERSION: "1.39"
  DOCKER_HOST: tcp://localhost:2375

stages:
  - build
  - deploy_dev
  - deploy_stg
  - deploy_prod

maven-build:
  image: maven:3.6-jdk-8
  stage: build
  script:
    - mvn verify -DskipTests
  variables:
    MAVEN_OPTS: "-Dmaven.repo.local=$CI_PROJECT_DIR/.m2/repository"
  artifacts:
    paths:
      - target/hello-world.jar
    expire_in: 1 week

dev-deployment:
  stage: deploy_dev
  image: google/cloud-sdk
  only:
    refs:
      - branches
  except:
    refs:
      - master
      - stg
  script:
    - deploy_vm dev

staging-deployment:
  stage: deploy_stg
  image: google/cloud-sdk
  only:
    refs:
      - master
      - stg
  script:
    - deploy_vm stg
  when: manual

production-deployment:
  stage: deploy_prod
  image: google/cloud-sdk
  only:
    refs:
      - master
      - stg
  script:
    - deploy_vm prod
  when: manual

script.sh

#!/bin/sh

export CI_BUILD_SHA="x${CI_BUILD_REF:0:8}"

deploy_vm() {
	if [ $1 == 'dev' ]
	then
		echo 'DEV DEPLOYMENT'
		echo $DEV_GCP_TOKEN > /tmp/key.json
		gcloud auth activate-service-account --key-file /tmp/key.json
		gcloud beta compute ssh --tunnel-through-iap --zone "us-central1-a" "spring-boot-vm" --project "cloudorbit-dev" --command="sudo systemctl stop hello-world"
		sleep 5
		gcloud compute scp target/hello-world.jar spring-boot-vm:/hello-world --zone=us-central1-a --project "cloudorbit-dev" --tunnel-through-iap
		gcloud beta compute ssh --tunnel-through-iap --zone "us-central1-a" "spring-boot-vm" --project "cloudorbit-dev" --command="sudo systemctl start hello-world"

	elif [ $1 == 'stg' ]
	then
		echo 'STAGE DEPLOYMENT'
		echo $STG_GCP_TOKEN > /tmp/key.json
		gcloud auth activate-service-account --key-file /tmp/key.json
		gcloud beta compute ssh --tunnel-through-iap --zone "us-central1-a" "spring-boot-vm" --project "cloudorbit-stg" --command="sudo systemctl stop hello-world"
		sleep 5
		gcloud compute scp target/hello-world.jar spring-boot-vm:/hello-world --zone=us-central1-a --project "cloudorbit-stg" --tunnel-through-iap
		gcloud beta compute ssh --tunnel-through-iap --zone "us-central1-a" "spring-boot-vm" --project "cloudorbit-stg" --command="sudo systemctl start hello-world"

	elif [ $1 == 'prod' ]
	then
		echo 'PROD DEPLOYMENT'
		echo $PROD_GCP_TOKEN > /tmp/key.json
		gcloud auth activate-service-account --key-file /tmp/key.json
		gcloud beta compute ssh --tunnel-through-iap --zone "us-central1-a" "spring-boot-vm" --project "cloudorbit-prod" --command="sudo systemctl stop hello-world"
		sleep 5
		gcloud compute scp target/hello-world.jar spring-boot-vm:/hello-world --zone=us-central1-a --project "cloudorbit-prod" --tunnel-through-iap
		gcloud beta compute ssh --tunnel-through-iap --zone "us-central1-a" "spring-boot-vm" --project "cloudorbit-prod" --command="sudo systemctl start hello-world"

	else
		echo 'Unknown environment "$1".'
	fi
}