How to start Docker daemon

Using Docker has become increasingly popular among developers and system administrators. However, to get started with Docker, it is important to understand how to run and configure Docker daemon. There are several steps involved in installing, configuring and starting Docker daemon, but once you know the process, it will be easy to use.

What is Docker Daemon and how to run it?

Definition of Docker Daemon

Docker daemon is a background service that manages the Docker engine, which allows the creation and management of Docker containers. The engine is responsible for building and running the containers, while the daemon is responsible for managing and monitoring the entire system.

How to run Docker Daemon on Linux

The installation process of Docker daemon on a Linux machine involves several steps. First, it is essential to ensure that your host machine is compatible. Docker supports several operating systems such as Ubuntu, Debian, and CentOS, among others.

To install Docker on a Linux machine, run the following command on the terminal:

sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io

This command ensures that the necessary components of Docker are installed on your machine.

How to run Docker Daemon on Windows

The process of installing and running Docker daemon on Windows is different from that of Linux. There are two ways to run Docker daemon on Windows: as a Windows service or in a Docker host using Docker client.

To install Docker on Windows, download Docker desktop from the official Docker website and run the installer. Docker desktop installs both Docker engine and Docker client on your machine.

How to Install and Configure Docker?

Installing Docker on Linux, Windows and MacOS

The installation of Docker on a Linux, Windows or MacOS machine involves a few steps depending on the operating system. As mentioned above, on Linux, you can use the following command:

sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io

On Windows, download and run the Docker desktop installer from the official Docker website. On MacOS, use the following command:

brew cask install docker

Configure Docker with Systemd

If you are using a Linux distribution with Systemd, you can configure Docker to start automatically when the machine boots. To do this, create a systemctl configuration file by running the following command:

sudo nano /etc/systemd/system/docker.service.d/docker.conf

Then add the following contents to that file:

[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock

Finally, restart Daemon:

sudo systemctl daemon-reload
sudo systemctl restart docker

Configure Docker with Configuration File

If you are running Docker on a Unix machine, use the following command to create a configuration file:

sudo nano /etc/docker/daemon.json

Specify the runtime and other required configurations in the file. For example:

{
  "runtimes":
  {
    "custom":
    {
      "path": "/usr/local/bin/my-custom-runtime.sh",
      "runtimeArgs": ["--debug=true"]
    }
  }
}

How to Start and Stop Docker Container?

How to Start Docker Container with Docker Run Command

Once you have installed and configured Docker, you can start and stop a Docker container using the docker run command. For example, to run the hello-world container, use the following command:

docker run hello-world

The above command pulls the hello-world image from the Docker registry and runs it. To stop a running Docker container, use the following command:

docker stop [container ID]

How to Stop Docker Container

Another way to stop and remove a running Docker container is by running the following command:

docker rm -f [container ID]

How to Troubleshoot Docker Daemon?

Check Docker Daemon Logs

If you encounter issues with Docker daemon, you can check the daemon logs for error messages by running the following command:

sudo journalctl -u docker.service

Debug Docker Daemon with Command Line

Use the following command to run Docker Daemon in debug mode to get more detailed error messages:

dockerd -D

Resolve Port conflicts and directory permissions

If you encounter issues with port conflicts or directory permissions, you can resolve them by using the following flags with the Docker run command:

-p : maps a host port to a container port.
-v : maps a host directory to a container directory.

How to Uninstall Docker?

Uninstall Docker on Linux

To uninstall Docker on Linux using the Terminal, run the following command:

sudo apt-get purge docker-ce

Uninstall Docker on Windows

To uninstall Docker on Windows, go to settings and navigate to Apps and Features. Select Docker Desktop and uninstall it from your machine.

In conclusion, with the above steps, you know how to run Docker daemon, start and stop containers, install, configure and uninstall Docker. Always remember that docker daemon is a critical piece in making sure that containers run smoothly. Happy development!

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