Docker compose is a tool in the Docker platform that is used to define and run multi-container applications. It lets us define how a container will behave when it is run in production, and also lets us define other services that it depends on and how services work with each other. Each application is a service as it defines the behavior of the container, for example, what port it runs on, what environment variables it uses, and so on. A YAML file is used for this. A single docker.compose.yml file can define all the services that are required for a multi-container application and can then be started with a single command. We will see more about Docker and docker -compose in Chapter 11, Deploying with Docker Compose.
The following table is a list of useful commands for Docker and Docker compose:
| docker build -t myapp:1.0. | Build an image from the Dockerfile in the current directory and tag the image |
| docker images | List all images that are locally stored with the Docker engine |
|
docker pull alpine:3.4
|
Pull an image from a registry |
| docker push myrepo/myalpine:3.4 | Push an image to a registry |
| docker login | Log in to a registry (the Docker Hub, by default) |
| docker run --rm -it -p 5000:80 -v /dev/code alpine:3.4 /bin/sh | Run a docker container
--rm: Remove container automatically after it exits |
| docker stop myApp | Stop a running container |
| docker ps | List the running containers |
| docker rm -f $(docker ps -aq) | Delete all running and stopped containers |
| docker exec -it web bash | Create a new bash process inside the container and connect it to the Terminal |
| docker logs --tail 100 web | Print the last 100 lines of a container's logs |
| docker-compose up | Start the services defined in the docker-compose.yml file in the current folder |
| docker-compose down |
Stop the services defined in the docker-compose.yml file in the current folder |