Docker cheat sheet

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When working with docker, there are a lot of commands to manage the container, images, troubleshoot issues or access useful information on runtime. The following are some commands to help with that kind of tasks.

Container Management

Below you can find the most common commands to interact with Docker containers.

# Show all running docker containers
docker ps

# Show all docker containers
docker ps -a

# Run a container
docker run <image>:<tag>

# Run a container and connect to it
docker run -it <image>:<tag>

# Run a container and clean it up after exit
docker run --rm <image>:<tag>

# Run a container in the background
docker run -d <image>:<tag>

# Stop a container
docker stop <container>

# Delete a container
docker rm <container>

# Kill a container
docker kill <container>

Image Management

Below you can find the most common commands to manage Docker images.

# List available local images
docker images

# Build an image with a dockerfile
docker build -t <image>:<tag> <run_directory> -f <dockerfile>

# Remove a local docker image
docker rmi <image>:<tag>

# Show metadata for an image
docker image inspect <image>

# Remove all unused docker images
docker image prune

Interaction among Host and Container

Even though Docker provides isolation into the container, sometimes we might need to perform son interaction between the Host machine and a container, for example: copying information, accessing a port in the container, or sharing a folder between the host and the container.

# Map a local port to a docker instance
docker run -d -p 127.0.0.1:<local_port>:<docker_port> <image>

# List the ports a docker container is running on
docker port <container> 

If we need to copying data from docker container to the host machine or vice-versa

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# Copy file or folder from a docker container to host machine
docker cp <container>:<container_dir> <local_dir>

# Copy file or folder from local machine onto a container
docker cp <local_dir> <container>:<container_dir>

Using volumes

# List volumes
docker volume ls

# Create a volume
docker volume create <volume>

# Delete a volume
docker volume rm <volume>

# Show volume metadata
docker volume inspect <volume>

# Delete all volumes not attached to a container
docker volume prune

# Mount a local directory to your container
docker run -v <local_dir>:<container_dir> <image>

Registry and Repository

These command help to connect a docker Repository of images, pull and push images to it.

# Login to a remote repository
docker login <repository>

# Search for docker images
docker search <image>

# Pull a docker image from a repository
docker pull <image>

# Push an image to your remote repository
docker push <image>:<tag>

#Retag a local image with a new image name and tag
docker tag <image>:<tag> <repository>/<image>:<tag>

Docker Compose

Below you can find the most common commands to interact with Docker Compose.

# Start your docker-compose defined resources in detached mode
docker-compose up -d -f <docker_compose_yaml>

# Stop all docker-compose resources
docker-compose stop

# Destroy all docker-compose resources
docker-compose down

# Show docker-compose processes
docker-compose ps

# Show docker-compose logs
docker-compose logs

# Show docker-compose resource consumption
docker-compose top

# Pull latest docker-compose images
docker-compose pull

Docker Troubleshooting

When an issue happens, we might need to access the logs or the internal of the container. For that purpose, we can use the following commands.

# Show the logs of a container
docker logs <container>

# Follow/tail the logs of a container
docker logs -f <container>

# Show timestamps on docker logs
docker logs -t <container>

# Execute a command on a container
docker exec -it <container_id> /bin/bash

There are some other useful commands to get information to troubleshoot an issue.

# Show details/metadata of a container
docker inspect <container>

# Show a 'top' view of processes running on a container
docker top <container>

# Show a 'top' view of all docker containers
docker stats

# Show any files that have changed since startup
docker diff <container>

# Connect to an already running container
docker attach <container>

# Show docker system wide information
docker system info

# Show docker disk space used
docker system df

References

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