How to use the command 'podman-compose' (with examples)

This article provides examples of how to use the ‘podman-compose’ command. ‘podman-compose’ is a command-line tool that allows users to run and manage container definitions using the Compose Specification. It is an alternative to the ‘docker-compose’ command and is commonly used with the Podman container engine.

Use case 1: List all running containers

Code:

podman-compose ps

Motivation: This use case is useful when you want to quickly check which containers are currently running.

Explanation: The ‘ps’ command is used to list the running containers managed by podman-compose. It provides information such as the container ID, name, and status.

Example output:

Name            Command  State   Ports
------------------------------------
webapp_1   /bin/sh -c npm start    Up
database_1  /docker-entrypoint.sh    Up

Use case 2: Create and start all containers in the background using a local ‘docker-compose.yml’

Code:

podman-compose up -d

Motivation: This use case is helpful when you want to launch all the containers defined in the local ‘docker-compose.yml’ file and run them in the background. This allows you to start the containers without blocking the console.

Explanation: The ‘up’ command is used to create and start containers defined in the ‘docker-compose.yml’ file. The ‘-d’ flag is used to start the containers in the background (detached mode).

Example output:

Creating webapp_1    ... done
Creating database_1 ... done

Use case 3: Start all containers, building if needed

Code:

podman-compose up --build

Motivation: This use case is useful when you have made changes to the container images defined in the ‘docker-compose.yml’ file and want to rebuild the images before starting the containers.

Explanation: The ‘–build’ flag is used to rebuild the container images before starting the containers. This is necessary when there are changes to the Dockerfiles or build context.

Example output:

Building webapp
Step 1/5 : FROM python:3.9
3.9: Pulling from library/python
...

Use case 4: Start all containers using an alternate compose file

Code:

podman-compose -f path/to/file up

Motivation: This use case is helpful when you want to use a different compose file to define the containers instead of the default ‘docker-compose.yml’ file.

Explanation: The ‘-f’ flag is used to specify an alternate compose file. The ‘path/to/file’ should be the path to the desired compose file.

Example output:

Creating custom_webapp_1    ... done
Creating custom_database_1 ... done

Use case 5: Stop all running containers

Code:

podman-compose stop

Motivation: This use case is useful when you want to stop all the running containers managed by podman-compose.

Explanation: The ‘stop’ command is used to stop the running containers. It gracefully stops the containers, allowing them to perform cleanup operations defined in their entrypoint scripts.

Example output:

Stopping webapp_1    ... done
Stopping database_1 ... done

Use case 6: Remove all containers, networks, and volumes

Code:

podman-compose down --volumes

Motivation: This use case is helpful when you want to completely remove all the containers, networks, and volumes created by podman-compose.

Explanation: The ‘down’ command is used to stop and remove all the containers, networks, and volumes created by podman-compose. The ‘–volumes’ flag is used to also remove the volumes associated with the containers.

Example output:

Stopping webapp_1    ... done
Stopping database_1 ... done
Removing webapp_1    ... done
Removing database_1 ... done
Removing network myapp_default

Use case 7: Follow logs for a container (omit all container names)

Code:

podman-compose logs --follow

Motivation: This use case is useful when you want to follow the logs of all containers managed by podman-compose without specifying individual container names.

Explanation: The ’logs’ command is used to display the log output of the containers. The ‘–follow’ flag is used to continuously display the logs as they are generated.

Example output:

webapp_1    | Server running at http://localhost:3000
database_1  | MySQL init process done. Ready for start up.

Use case 8: Run a one-time command on a service with no ports mapped

Code:

podman-compose run service_name command

Motivation: This use case is helpful when you want to execute a one-time command on a specific service managed by podman-compose. It is particularly useful when the service does not have any ports mapped.

Explanation: The ‘run’ command is used to run a command in a specific service. ‘service_name’ should be replaced with the name of the service defined in the compose file, and ‘command’ should be replaced with the command to be executed.

Example output:

Running command 'bash' in service 'webapp_1'
root@container:/app#

Conclusion:

The ‘podman-compose’ command provides a convenient way to run and manage container definitions using the Compose Specification. With its various options, it allows users to start, stop, build, and interact with containers managed by podman-compose. By understanding these use cases, users can effectively use podman-compose for their container orchestration needs.