Docker Express API

Following tutorial on: https://itnext.io/lets-dockerize-a-nodejs-express-api-22700b4105e4.

I am using environment secrets using this article: https://medium.com/codait/environment-variables-or-keeping-your-secrets-secret-in-a-node-js-app-99019dfff716.

Demo

You can find an example of this application running on heroku here.

Instructions

1. Build the docker image docker-compose build

2. Run the container docker-compose up or in the background docker-compose up -d

3. Use the following commands to control the container docker-compose stop docker-compose start docker-compose run <custom service>

• If docker is running in the background and you still want to see the console outputs, use the following command: docker logs $(sudo docker ps -aq --filter name=<>)

• Or for live console outputs use docker logs -f <CONTAINER>

Running on different port

If you want to run this image on a different port you need to use the following: docker run --name <image_name> -p <local_port>:<container_port>

Deploying with Heroku

1. Run command heroku login to login to heroku.
2. Create your app with heroku heroku create <app_name>
3. Create a heroku.yml file in your application's root directory. The following example heroku.yml specifies the Docker image to build for the app’s web process:

build:
docker:
  web: Dockerfile
run:
web: npm run start

In this example, both heroku.yml and Dockerfile are in the same directory. If the Dockerfile lives in a non-root directory, specify the relative path in the build.docker.web value, such as app/Dockerfile.

If you don’t include a run section, Heroku uses the CMD specified in the Dockerfile.

4. Commit the file to your repo: git add heroku.yml git commit -m "Add heroku.yml"

5. Set the stack of your app to container: heroku stack:set container

6. Push your app to Heroku: git push heroku master Your application will be built, and Heroku will use the run command provided in heroku.yml instead of your Procfile.

Note: The port is set dynamically by heroku, so you need to user process.env.PORT variable on your server to make it work in docker as well.