Install Docker and Docker Compose on Ubuntu Linux

This post shows students and new users the steps to install Docker and Docker Compose on Ubuntu Linux.

Docker software allows virtualization at the operating system level. Unlike VirtualBox and VMware Workstation, you run virtual applications as containers. Docker was developed by Docker Inc and runs software packages as containers which makes building applications that are easily shared and can run anywhere.

Docker Compose is a tool for defining and running multi-containers Docker applications. It uses YAML files to configure application services, then with a single command using the definitions in the file to start these services based on the configurations.

If you want to build an environment on Ubuntu to build Docker containers, you’ll want to install Docker as well as Docker Compose to make your job easier.

How to add Docker repository on Ubuntu Linux

Docker has two editions:  The Enterprise Edition (EE) and the Community Edition (CE).

For this tutorial, we’re going to be installing the community edition of Docker.

If you always want to automatically get the latest version of Docker on Ubuntu, you must add its official repository to the Ubuntu system. To do that, run the commands below to install prerequisite packages.

sudo apt update
sudo apt-get install apt-transport-https ca-certificates curl gnupg-agent software-properties-common

Next, run the commands below to download and install Docker’s official GPG key. The key is used to validate packages installed from Docker’s repository making sure they’re trusted.

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo apt-key fingerprint 0EBFCD88

You should see an output shown below:

Output:
pub   rsa4096 2017-02-22 [SCEA]
      9DC8 5822 9FC7 DD38 854A  E2D8 8D81 803C 0EBF CD88
uid           [ unknown] Docker Release (CE deb) <docker@docker.com>
sub   rsa4096 2017-02-22 [S]

Now that the official GPG key is installed, run the commands below to add its stable repository to Ubuntu. To add the nightly or test repository, add the word nightly or test (or both) after the word stable in the commands below.

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

At this point, Docker’s official GPG and repository should be installed on Ubuntu.

For those who currently have older versions of Docker, run the commands below to remove them.

sudo apt remove docker docker-engine docker.io containerd runc

When you have removed all previous versions of Docker, run the commands below to install the latest and current stable version of Docker.

To install a specific version of Docker, run the apt-cache command. Then select the version to install.

apt-cache madison docker-ce

Output:
docker-ce | 5:18.09.5~3-0~ubuntu-bionic | https://download.docker.com/linux/ubuntu bionic/stable amd64 Packages
docker-ce | 5:18.09.4~3-0~ubuntu-bionic | https://download.docker.com/linux/ubuntu bionic/stable amd64 Packages
docker-ce | 5:18.09.3~3-0~ubuntu-bionic | https://download.docker.com/linux/ubuntu bionic/stable amd64 Packages
docker-ce | 5:18.09.2~3-0~ubuntu-bionic | https://download.docker.com/linux/ubuntu bionic/stable amd64 Packages
.

Now to install a specific version, run the commands below with the version you wish to install

sudo apt-get install docker-ce=5:18.09.5~3-0~ubuntu-bionic docker-ce-cli=5:18.09.5~3-0~ubuntu-bionic containerd.io

If you just want to latest version without specifying the above, run the commands below. The command below will always install the highest possible version.

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

That should install Docker software on Ubuntu.

Verify that Docker CE is installed correctly by running the hello-world image, run the commands below:

sudo docker run hello-world

You should see a similar line below:

Output:
Hello from Docker!
This message shows that your installation appears to be working correctly.

Docker is installed correctly!

How to install Docker Compose on Ubuntu Linux

On Ubuntu Linux, you can download the Docker Compose binary from the Compose repository release page on GitHub.

To install it, run the commands below to download version 1.24.0. As of this writing, this was the current version.

sudo curl -L "https://github.com/docker/compose/releases/download/1.24.0/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

To install a different version of Compose, substitute 1.24.0 with the version of Compose you want to use.

After downloading it, run the commands below to apply executable permissions to the binary file and create a symbolic link to /usr/binary

sudo chmod +x /usr/local/bin/docker-compose
sudo ln -s /usr/local/bin/docker-compose /usr/bin/docker-compose

That should get Docker Compose working. To test, run the commands below:

docker-compose --version

You should see similar output as below:

Output:
docker-compose version 1.24.0, build 0aa59064

That should do it!

To run Docker as a non-root user, add your user account to Docker’s group by running the commands below:

sudo usermod -aG docker $USER

Log out and back in, and you should be able to run docker with your standard account.

Conclusion:

This post showed you how to install Docker and Docker Compose on Ubuntu Linux. If you find any error above or have something to add, please use the comment form below.