Python Heroku GitLab CI/CD Example

.gitlab-ci.yml

stages:
  - test
  - deploy

test_flask:
  variables:
    REDIS_URL: redis://redis:6379
  services:
    - redis
  image: python:3.7-alpine
  stage: test
  tags:
    - docker
  script:
    - pip install -r requirements.txt
    - python app.test.py

deploy_heroku:
  image: kudaliar032/dpl
  stage: deploy
  only:
    - master
  tags:
    - docker
  script:
    - dpl --provider=heroku --app=${APP_NAME} --api-key=${HEROKU_API}
  environment:
    name: heroku
    url: https://${APP_NAME}.herokuapp.com/

app.py

import time
import redis
import os
from flask import Flask

app = Flask(__name__)
cache = redis.from_url(os.environ.get("REDIS_URL"))

def get_hit_count():
    retries = 5
    while True:
        try:
            return cache.incr('hits')
        except redis.exceptions.ConnectionError as exc:
            if retries == 0:
                raise exc
            retries -= 1
            time.sleep(0.5)

@app.route('/')
def hello():
    count = get_hit_count()
    return 'Hello World! Saya sudah terlihat {} kali.'.format(count)

if __name__ == "__main__":
    app.run(host="0.0.0.0", debug=True)

app.test.py

import unittest
from app import app

class BasicTestCase(unittest.TestCase):
    def test_home(self):
        tester = app.test_client(self)
        response = tester.get('/', content_type='html/text')
        self.assertEqual(response.status_code, 200)

if __name__ ==  '__main__':
    unittest.main()

Procfile

web: gunicorn app:app

requirements.txt

Click==7.0
Flask==1.1.1
gunicorn==20.0.4
itsdangerous==1.1.0
Jinja2==2.10.3
MarkupSafe==1.1.1
redis==3.3.11
Werkzeug==0.16.0