Docker Commands

Most Important

Management

• docker create <image_name>: Creates a new container from an image.
• docker build: Builds a Docker image from a Dockerfile.
  • -t <image_name>: Assigns a name and optional version to the created image.
  • -f <path_to_dockerfile>: Specifies the path to the Dockerfile if it’s not in the current directory.
  • To exclude files, create a .dockerignore file.

• docker run <image:version>: Starts a container from an image.
  • -d: Runs the container in the background.
  • -p <host_port>:<container_port>: Maps a host port to a container port.
  • --name <name>: Assigns a name to the container.
  • -v <host_path>:<container_path>: Maps a host directory to a container directory.
• docker stop <container_id>: Stops a running container.
• docker restart <container_name_or_id>: Restarts a stopped container.

• docker rmi <image_name>: Removes an image.
• docker rm <container_id>: Removes a stopped container.
• docker rename <old_name> <new_name>: Renames a container.

Docker Hub

• docker pull <image_name:version>: Downloads an image from a registry.
• docker push <image_name:version>: Publishes a Docker image to a registry.
• docker login: Logs in to a Docker registry account.
• docker logout: Logs out of a Docker registry account.

Docker Info

• docker info: Displays information about the Docker system.

• docker images: Lists the available images.
• docker image inspect <image_name>: Displays detailed information about an image.

• docker ps: Lists the active containers.
  • -a: Lists all containers, including stopped ones.
• docker container inspect <container_id>: Displays detailed information about a container.
• docker logs <container_id>: Displays the logs of a container.

Host to Container

• docker cp <container_id>:<container_path> <host_path>: Copies files between the host and container.

• docker exec <container_id> <command>: Executes a command within a running container.

• docker network create <network_name>: Creates a new network with the specified name.

• docker volume create <volume_name>: Creates a new volume with the specified name.

docker-compose.yml (orchestrate containers)

• docker-compose up: Starts the application
  • -d: Runs the containers in the background
  • --build: Forces the build of images before starting the containers
• docker-compose down: Stops and removes the application
• docker-compose ps: Shows the status of the containers in the application
• docker-compose exec <service_name> <command>: Executes a command inside a service container
• docker-compose logs <service_name>: Displays the logs of a service container

Example of a ‘docker-compose.yml’ file:

version: '3.9'

services:
  web:
    container_name: nginx-web
    image: nginx:latest
    ports:
      - 80:80
    volumes:
      - ./html:/usr/share/nginx/html
    networks:
      - frontend

  app:
    container_name: my-app
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - 5000:5000
    depends_on:
      - db
    environment:
      - ENV_VAR=example
    volumes:
      - ./app:/app
    networks:
      - frontend
      - backend

  db:
    container_name: mysql-db
    image: mysql:latest
    restart: always
    environment:
      - MYSQL_ROOT_PASSWORD=secret
      - MYSQL_DATABASE=mydb
    volumes:
      - ./db_data:/var/lib/mysql
    networks:
      - backend

networks:
  frontend:
  backend:

Dockerfile (building custom image)

FROM: Defines the base image on which the new image is built.
RUN: Executes a command to install packages or run commands inside the container.
COPY or ADD: Copies files or directories from the host into the container.
WORKDIR: Sets the working directory for subsequent instructions in the Dockerfile.
EXPOSE: Declares the port on which the container will listen for external communication.
CMD: Specifies the default command to be executed when starting a container.
ENTRYPOINT: Defines the executable command that is always executed when the container starts.
ENV: Sets environment variables within the container.
VOLUME: Declares one or more volumes to be used by the container.
LABEL: Adds metadata to an image.

Example of a ‘Dockerfile’ file:

# Define the base image
FROM python:3.9

# Set the working directory
WORKDIR /app

# Copy the requirements file and install dependencies
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

# Copy the application code
COPY . .

# Set environment variables
ENV ENV_VAR=example

# Expose a port
EXPOSE 8000

# Set the default command
CMD ["python", "app.py"]

# Add metadata labels
LABEL maintainer="Your Name <your.email@example.com>"
LABEL version="1.0"
LABEL description="My Dockerized App"

# Define a volume
VOLUME /data

All Docker CLI Commands (A-Z)

show commands

Command	Description
attach	Attach local standard input, output, and error streams to a running container
build	Build an image from a Dockerfile
builder	Manage builds
checkpoint	Manage checkpoints
commit	Create a new image from a container’s changes
config	Manage Swarm configs
container	Manage containers
context	Manage contexts
cp	Copy files/folders between a container and the local filesystem
create	Create a new container
diff	Inspect changes to files or directories on a container’s filesystem
events	Get real time events from the server
exec	Execute a command in a running container
export	Export a container’s filesystem as a tar archive
history	Show the history of an image
image	Manage images
images	List images
import	Import the contents from a tarball to create a filesystem image
info	Display system-wide information
inspect	Return low-level information on Docker objects
kill	Kill one or more running containers
load	Load an image from a tar archive or STDIN
login	Log in to a registry
logout	Log out from a registry
logs	Fetch the logs of a container
manifest	Manage Docker image manifests and manifest lists
network	Manage networks
node	Manage Swarm nodes
pause	Pause all processes within one or more containers
plugin	Manage plugins
port	List port mappings or a specific mapping for the container
ps	List containers
pull	Download an image from a registry
push	Upload an image to a registry
rename	Rename a container
restart	Restart one or more containers
rm	Remove one or more containers
rmi	Remove one or more images
run	Create and run a new container from an image
save	Save one or more images to a tar archive (streamed to STDOUT by default)
search	Search Docker Hub for images
secret	Manage Swarm secrets
service	Manage Swarm services
stack	Manage Swarm stacks
start	Start one or more stopped containers
stats	Display a live stream of container(s) resource usage statistics
stop	Stop one or more running containers
swarm	Manage Swarm
system	Manage Docker
tag	Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
top	Display the running processes of a container
trust	Manage trust on Docker images
unpause	Unpause all processes within one or more containers
update	Update configuration of one or more containers
version	Show the Docker version information
volume	Manage volumes
wait	Block until one or more containers stop, then print their exit codes

Sources

Markdown table-generation: https://www.tablesgenerator.com/markdown_tables
Docker CLI commands: https://docs.docker.com/engine/reference/commandline/cli/