My Docker Cheatsheet

Containers Commands

To run an image:

docker container run <image_name> [command]

It downloads the image from docker hub if the image is not available locally.

• --publish <host_port>:<container_port>: forwards the host port to container port.

• --name <container_name>: assigns an arbitrary name for the container.

• -e <env_name>=<env_value>: sets an environment variable inside the container.

• -it: starts a new interactive container

• --net: specifies the network of the container

• --net-alias: adds an alias DNS record for the container

• --rm: to remove the container automatically after finishing its job.

• -v <vol_name>:<vol_path>: specifies a volume for the container

To stop a running container:

docker container stop <container_name>

To start a stopped container:

docker container start <container_name>

To run a new command on an existing container:

docker container exec <container_name> <command>

• -it: runs the command interactively.

To view all running containers:

docker container ls

• -a: lists all containers including the stopped containers

To view the logs of a container:

docker container logs <container_name>

To remove a container:

docker container rm <container_name>

Notice that the container must be stopped before removing.

• -f: forces the container to be stopped and removed.

To view exposed ports inside a container:

docker container port <container_name>

To view the processes running inside the container:

docker container top <container_name>

To view live performance data on all containers:

docker container stats 

To show metadata about the container (startup, volumes, networking, etc):

docker container inspect <container_name>

• --format: formats the output of docker inspect. e.g: --format '{{ .NetworkSettings.IPAddress }}' to get the IP address of the container.

Networking Commands

To create a network:

docker network create <network_name>

• --driver: to set the driver of the network (bridge, host, null)

To remove a network:

docker network rm <network_name>

To see a list of networks:

docker network ls

To see metadata about a network:

docker network inspect <network_name>

To dynamically attach a network to a container:

docker network connect <network_name> <container_name>

To dynamically disconnect a network from a container:

docker network disconnect <network_name> <container_name>

Note: Containers on the same custom network can access each other using their names instead of their IP address. For the bridge network we must use -link to link containers.

Images Commands

To pull an image from the registry:

docker image pull <image_name>

To see a list of pulled images:

docker image ls

To remove an image:

docker image rm <image_name>

To see the image's changes history:

docker image history <image_name>

To see metadata about the image:

docker image inspect <image_name> 

To assign a new tag to an image:

docker image tag <src_tag> <dst_tag>

To push an image:

docker image push <image_name>

To build an image using a Dockerfile:

docker image build <dockerfile_path>

• -t: Tags the image after building

• -f: specifies the name of the Dockerfile

Volume Commands

To create new volume:

docker volume create <volume_name>

To view all volumes:

docker volume ls

To remove a volume:

docker volume rm <volume_name>

To remove all unused volumes:

docker volume prune

To see metdata about a volume:

docker volume inspect <volume_name>

Dockerfile

FROM

Specifies the base image of the image:

FROM <image_name>

RUN

Runs a command:

RUN <command1> && <command2> ...
RUN ["executable", "param1", "param2"]

• Putting && between the commands ensures that they will create only one layer in image.

ENV

Sets an environment variable:

ENV <variable_name>=<variable_value> ...
ENV <variable_name> <<variable_value>

• We can use env variables in dockerfile like this: ${variable_name}

WORKDIR

Changes the current working directory inside the container:

WORKDIR <path>

COPY

Copies files or directories from our system into the container:

COPY <src_path> <dest_path>

CMD

Provides defaults for an executing container:

CMD ["executable", "param1", "param2"]
CMD ["param1", "param2"]
CMD <command>

• There can only be one CMD instruction in a Dockerfile. If you list more than one CMD then only the last CMD will take effect.

EXPOSE

Informs Docker that the container listens on the specified network ports at runtime:

EXPOSE <port> [<port>/protocol]

• The EXPOSE instruction does not actually publish the port. It functions as a type of documentation between the person who builds the image and the person who runs the container

VOLUME

Creates a mount point with the specified name:

VOLUME ["vol_path"]
VOLUME <vol_path> ...

Docker-Compose

services:
  service1:
    build: 
      context: .
      dockerfile: <dockerfile_name>
    image: <image1_name>
    ports:
      - '<host_port1>:<container_port1>'
      - '<host_port2>:<container_port2>'
    volumes:
      - <bind_path1> or <named_vol1>:<container_path1>
      - <bind_path2> or <named_vol2><container_path2>
    environment:
      - <key1>=<value1>
      - <key2>=<value2>
    depends_on:
      - "service2"

  service2:
    ...

volumes:
  <named_vol1>:
  <named_vol2>:  

network:
    ...

To run the docker-compose file;

docker-compose up

• -f: specifies the name of the docker-compose file

• -d: runs docker-compose in background

   

To stop the running docker-compose:

docker-compose down

• -v: removes all volumes defined in volumes section after stopping

• --rmi type : removes images after downing the docker-compose

  • type=all: removes all images

  • type=local: removes only images that don't have custom tag set by the image field.

To rebuild images that are created using docker-compose:

docker-compose build