Introduction

In this article, I will explore various Docker commands, which are essential for managing your Docker containers and images. I will provide example code and output for each command to help you better understand their functionality.

docker pull

The docker pull command allows you to download an image from a remote Docker registry, such as Docker Hub.

bash

$ docker pull ubuntu:20.04

20.04: Pulling from library/ubuntu
Digest: sha256:cfb43ffdb609eb9c3ecd47d8e48e16f7abbb1c95b7340d8f883942e0730e950a
Status: Downloaded newer image for ubuntu:20.04
docker.io/library/ubuntu:20.04

docker build

The docker build command creates Docker images from a Dockerfile and a build context (typically your project directory).

bash

$ docker build -t yourusername/your-image:tag .

Sending build context to Docker daemon  2.048kB
Step 1/5 : FROM node:14
 ---> 91e0ff2b2a31
Step 2/5 : WORKDIR /app
 ---> Using cache
 ---> 0a0d332bddc2
Step 3/5 : COPY package*.json ./
 ---> Using cache
 ---> 7bf6e8c6d4ea
Step 4/5 : RUN npm install
 ---> Using cache
 ---> 15a0c0a4812e
Step 5/5 : COPY . .
 ---> 9adad8d1eeca
Successfully built 9adad8d1eeca
Successfully tagged yourusername/your-image:tag

docker run

The docker run command creates and starts a new container from a Docker image.

bash

$ docker run -d -p 8080:80 --name your-container yourusername/your-image:tag

ac7e2b3a3f7de342d0a16a7f13ea8c3425d58f5e5c5e5eb5

docker exec

The docker exec command allows you to execute commands inside a running container.

bash

$ docker exec -it your-container bash

root@ac7e2b3a3f7d:/app#

docker stop

The docker stop command stops a running container.

bash

$ docker stop your-container

your-container

docker start

The docker start command starts a stopped container.

bash

$ docker start your-container

your-container

docker restart

The docker restart command restarts a running container.

bash

$ docker restart your-container

your-container

docker push

The docker push command uploads your Docker image to a remote registry.

bash

$ docker push yourusername/your-image:tag

The push refers to repository [docker.io/yourusername/your-image]
tag: digest: sha256:0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef size: 1234

docker ps

The docker ps command lists all running containers.

bash

$ docker ps

CONTAINER ID   IMAGE                      COMMAND                  CREATED          STATUS          PORTS                  NAMES
ac7e2b3a3f7d   yourusername/your-image:tag   "docker-entrypoint.s…"   3 minutes ago    Up 3 minutes    0.0.0.0:8080->80/tcp   your-container

docker images

The docker images command lists all Docker images available on your system.

bash

$ docker images

REPOSITORY             TAG       IMAGE ID       CREATED          SIZE
yourusername/your-image tag       9adad8d1eeca   4 hours ago      939MB
ubuntu                 20.04     2c047404e52d   2 weeks ago      72.9MB
node                   14        91e0ff2b2a31   3 weeks ago      943MB

docker rm

The docker rm command removes a stopped container.

bash

$ docker rm your-container

your-container

docker rmi

The docker rmi command removes an unused Docker image.

bash

$ docker rmi yourusername/your-image:tag

Untagged: yourusername/your-image:tag
Deleted: sha256:9adad8d1eeca0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e0e

docker logs

The docker logs command displays the logs of a container.

bash

$ docker logs your-container

Starting application...
Listening on port 80

docker attach

The docker attach command allows you to attach your terminal to a running container.

bash

$ docker attach your-container

Listening on port 80

docker cp

The docker cp command allows you to copy files between a container and your host system.

bash

$ docker cp your-container:/app/data.txt /path/to/host/data.txt

(no output unless there's an error)

docker commit

The docker commit command creates a new image from a container's changes.

bash

$ docker commit -m "Added new features" -a "Your Name" your-container yourusername/your-image:new-tag

sha256:abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789

docker system prune

The docker system prune command removes unused data, such as stopped containers, unused networks, and dangling images.

bash

$ docker system prune

WARNING! This will remove:
  - all stopped containers
  - all networks not used by at least one container

Docker Commands

Introduction

docker pull

docker build

docker run

docker exec

docker stop

docker start

docker restart

docker push

docker ps

docker images

docker rm

docker rmi

docker logs

docker attach

docker cp

docker commit

docker system prune

CMD vs. ENTRYPOINT in Dockerfile

Docker Volume Mounting

Ryusei Kakujo