Connecting to the Docker Daemon

Docker daemon is the background process that manages and runs Docker containers on a system. It provides an API that allows you to control and manage containers, images, networks, and other Docker resources. In this article, we will explore how to connect to the Docker daemon and perform various operations using the Docker CLI (Command Line Interface).

To connect to the Docker daemon, you need to execute commands using the Docker CLI, which communicates with the daemon through its API. Here are the steps to connect to the Docker daemon:

1. Open a terminal or command prompt on your system.
2. Ensure that the Docker daemon is running. You can check its status using the following command:

sudo systemctl status docker

If the daemon is not running, you can start it using the following command:

sudo systemctl start docker

1. Once the daemon is running, you can connect to it using the docker command. For example, to list all running containers, you can execute:

docker ps

This command will communicate with the daemon, retrieve the list of running containers, and display them in the terminal.

You can also use flags or arguments with the docker command to perform various operations, such as pulling images, creating containers, and running commands inside containers. For example, to pull an image using the docker command:

docker pull ubuntu

This command will communicate with the daemon, pull the Ubuntu image from the Docker Hub, and download it to your system.

Now that you have connected to the Docker daemon and performed some basic operations, let’s explore some common Docker CLI commands and their uses:

• docker ps: Lists all running containers.
• docker images: Lists all available images.
• docker info: Displays information about the Docker installation, such as version, operating system, and kernel version.
• docker run: Runs a new container from an image. You can specify various options and parameters with this command, such as container name, exposed ports, environment variables, and command to run inside the container.
• docker stop: Stops a running container. You need to specify the container ID or name with this command.
• docker rm: Removes a container once it is stopped. Again, you need to specify the container ID or name with this command.
• docker login: Logs in to the Docker Hub or other registry to pull private images or push images to a repository. You need to provide your username and password with this command.
• docker tag: Tags an image with a repository name and optionally a tag. This is useful when uploading images to a registry or when referring to an image by a specific repository and tag in a docker run command.

These are just some of the common Docker CLI commands that you can use to manage and control Docker containers on your system. Remember that each command has its own set of options and parameters that you can use to fine-tune your containerized applications. Always refer to the official Docker documentation for detailed information about each command and its usage.