Installing Docker CE on Ubuntu

Docker CE (Community Edition) is a platform that allows working with containerized applications. Such applications are shipped in the containers, which contain all the necessary resources for the applications to operate. This allows to quickly build, deploy, and debug applications.

Containers are similar to virtual machines, but more lightweight. To isolate containerized application's resources, containers rely on the operation system on which they are running.

Make sure that:

• You have an access to the terminal of the Ubuntu host, on which you are planning to install Docker CE.
• You can use sudo on that host to run the commands on behalf of superuser (root).

1. Connect to the terminal.

   All further actions listed below are to be performed in this terminal.

2. Install the packages that are required for the further installation process:

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   sudo apt update && \sudo apt install -y \  apt-transport-https \  ca-certificates \  curl \  software-properties-common

3. Add the Docker repository's GPG key to the keyring:

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   curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

4. Make sure that the GPG key was successfully added:

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   apt-key list

   The command's output should contain the information about Docker repository's GPG key.

   Example output

5. Add the Docker repository:

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   sudo add-apt-repository -u "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

6. Make sure that the repository was successfully added:

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   apt-cache policy docker-ce

   The command's output should contain the information about the installation candidates for the docker-ce package.

   Example output

7. Install Docker CE:

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   sudo apt install docker-ce -y

1. Connect to the terminal.

   All further actions listed below are to be performed in this terminal.

2. Make sure that Docker CE is installed and running:

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   sudo systemctl status docker --no-pager -l

   The command's output should contain the information that the service is in active (running) state.

   Example output

3. Get general information about the installed Docker CE:

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   sudo docker info

   Example output

4. Run the hello-world test container:

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   sudo docker run --rm hello-world

   The container will display a greeting message and terminate.

   Example output