20 Essential Docker Commands Every Developer Should Know
Tags: docker, devops, deployment
Published: 2023-08-08 04:08:53

Introduction:

Docker has revolutionized the way we develop, deploy, and manage applications. Its containerization technology allows developers to package applications and their dependencies into a single unit, ensuring consistency across different environments. Whether you're new to Docker or a seasoned developer, mastering essential Docker commands is crucial for efficient container management. In this article, we'll explore 20 Docker commands that every developer should know.

docker --version:
The first step in working with Docker is to ensure you have it installed. Running docker --version will display the installed Docker version, confirming that everything is set up correctly.

docker info:
For a comprehensive overview of your Docker installation, utilize docker info. This command provides valuable information about system resources, storage, networking, and more.

docker pull <image>:
Before running containers, you need to download the necessary Docker images from a registry like Docker Hub. Use docker pull <image> to fetch an image and make it available on your system.

docker build -t <image_name> .:
Creating custom Docker images is common practice. The docker build command with the -t flag lets you build an image from a Dockerfile located in the current directory and assigns it a meaningful tag.

docker images:
To view all the Docker images available on your system, simply execute docker images. This command provides a list of images, their tags, creation dates, and sizes.

docker run <image>:
The docker run command is fundamental for starting containers. By providing the desired image name, you can create and launch a new container instance.

docker ps:
To check the running containers on your system, use docker ps. This command displays a list of containers along with their IDs, names, and statuses.

docker ps -a:
For an overview of all containers, including those that have stopped running, run docker ps -a. This is useful for inspecting the history of your containers.

docker start <container>:
To start a stopped container, use docker start <container>. This command resumes the container's execution from the point where it was paused.

docker stop <container>:
Stopping a running container is achieved with docker stop <container>. This command gracefully terminates the container's processes.

docker restart <container>:
Sometimes, you may need to restart a container to apply changes or reset its state. The docker restart <container> command accomplishes this.

docker rm <container>:
Once a container is no longer required, you can remove it using docker rm <container>. This frees up resources and helps keep your system clean.

docker rmi <image>:
When an image is no longer needed, you can delete it with docker rmi <image>. However, ensure that no containers are based on that image before removal.

docker exec -it <container> <command>:
To execute a command interactively within a running container, use docker exec -it <container> <command>. This is valuable for troubleshooting and debugging purposes.

docker logs <container>:
Accessing a container's logs is essential for understanding its behavior and identifying potential issues. Employ docker logs <container> to view the container's log output.

docker cp <container>:<src_path> <dest_path>:
Copying files or directories between the host and a container is straightforward with docker cp. This command helps in moving data in and out of containers.

docker network ls:
Docker networks facilitate communication between containers. Use docker network ls to see a list of networks available on your system.

docker volume ls:
Docker volumes are used to persist data beyond the container's lifecycle. docker volume ls allows you to see a list of volumes available on your system.

docker-compose up:
For multi-container applications, Docker Compose is an invaluable tool. docker-compose up starts all services defined in the docker-compose.yml file.

docker-compose down:
When you want to stop and remove containers, networks, and volumes defined in the docker-compose.yml file, use docker-compose down.

Conclusion:

Mastering these 20 essential Docker commands will empower developers to efficiently work with containers, build custom images, manage networks, and persist data. Docker's widespread adoption in the software industry makes these commands indispensable for streamlining development and deployment workflows. By incorporating these tools into your daily development routine, you can unlock the full potential of containerization and accelerate your software development journey. Happy Dockerizing!