Docker Workshop 101

Topics

• Set up a sample Node Express app listening to port 3000
• Dockerize that Node app:
  • what are base images and Docker Hub
  • exposing ports
  • mounting volumes
  • how to build your own Docker images: docker build -t your-image-name:latest .
  • how to start containers using images: docker run --name your-container-name -p 3000:3000 your-image-name:latest
  • how to start the same container, now mounting a volume: docker run --name your-container-name -p 3000:3000 -v ./greeting-custom.txt:/src/app/greeting.txt your-image-name:latest
    • highlight how you can mount any file, from anywhere you're starting the container
• Start a Postgres container
  • docker run --name postgres -p 5432:5432 -e POSTGRES_USER=test -e POSTGRES_PASSWORD=secret -e POSTGRES_DB=foobar postgres:13.3
  • show how you can connect to the Postgres container just like any other installed-on-host Postgres or some other remote Postgres
• Connect Node app with Postgres
  • show running the Node app on host and making it connect to the Postgres container
• Intro Docker Compose by composing the Node app and the Postgres container
  • highlight how the Node app cannot resolve localhost to our DB in the docker-compose.yml
  • highlight the special DNS name host.docker.internal which resolves to the host's IP address, but this only works cos we're exposing the DB container's port at the host
  • highlight how service names in docker-compose.yml becomes resolvable DNS names, when in containers participating in that docker-compose.yml
• Add a web server service (Nginx) to the docker-compose.yml, in preparation for serving a React app
  • show how to create a simple Dockerfile that copies over the static files from the built React app to the folder in the Nginx container that Nginx will serve content out of