docker Command: Tutorial & Examples
Manage docker containers
Docker is an open-source platform that automates the deployment, scaling, and
management of applications inside lightweight, portable, self-sufficient containers. The
docker command is the main
command used to interact with Docker. It is used to create, manage, and delete Docker containers, images, networks, and
What Does the
docker Command Do?
docker command provides a command line interface (CLI) to interact with the Docker daemon,
which is the background service running on the host that manages building, running and distributing Docker containers.
The command allows you to build, run, manage, and distribute Docker containers.
How Does the
docker Command Work?
docker command sends commands to the Docker daemon, which then performs the requested action. For example, if you
run the command
docker run ubuntu:18.04, the Docker CLI sends a request to the Docker daemon to run a Docker container
with the Ubuntu 18.04 image.
docker run ubuntu:18.04
How to Use the
To use the
docker command, you first need to have Docker installed on your system. Once Docker is installed, you can
docker command followed by a command like
Here are some basic examples of how to use the
To pull (download) an image from Docker Hub:
docker pull ubuntu:18.04
To run a Docker container:
docker run ubuntu:18.04
To list all running Docker containers:
To stop a running Docker container:
docker stop container_id
Why is the
docker Command Important?
docker command is important because it is the primary way of interacting with Docker. Without the
command, you would have to interact with the Docker API directly, which would be much more complex and time-consuming.
docker Command Parameters
There are many parameters that can be used with the
docker command. Here are a few of the most common ones:
-i, --interactive: Keeps STDIN open, even if not attached. Useful for interactive sessions.
-t, --tty: Allocates a pseudo-TTY. Useful for attaching an interactive shell.
-p, --publish: Publishes a container’s port to the host. Format:
-d, --detach: Runs the container in the background.
--name: Assigns a name to the container.
To run a Docker container in detached mode, with an interactive shell, and with a specific name, you would use the following command:
docker run -dit --name my_container ubuntu:18.04
Potential Problems and Pitfalls
docker command is powerful and flexible, there are a few potential issues to be aware of:
- Docker Daemon Not Running: If the Docker daemon is not running, you will get an error message when you try to run
dockercommand. To fix this, you need to start the Docker daemon.
- Insufficient Resources: If your system does not have enough resources (CPU, memory, disk space) to run a Docker
docker runcommand will fail. You may need to free up resources or add more resources to your system.
- Networking Issues: Docker containers can sometimes have issues connecting to the network. This could be due to a network issue on your system, or a problem with Docker's networking configuration.
- Image Not Found: If you try to run a Docker container with an image that does not exist on your local system or on
Docker Hub, you will get an error message. You need to pull the image first with the