How to Install Docker On Ubuntu 18.04

October 22, 2018

Docker is an increasingly popular software package that creates a container for application development.

Developing in Docker speeds up applications, as it shares the kernel and other resources, instead of requiring dedicated server resources.

There are two versions of Docker – Docker CE (Community Edition) and Docker EE (Enterprise Edition). If you have a small-scale project, or you’re just learning, you will want to use Docker CE.

In this tutorial, learn how to install Docker on Ubuntu 18.04.

install docker on ubuntu 18.04

Prerequisites

  • Ubuntu 18.04 64-bit operating system
  • A user account with sudo privileges
  • Command-line/terminal (CTRL-ALT-T or Applications menu > Accessories > Terminal)
  • Docker software repositories (optional)

Option 1: Install Docker on Ubuntu Using Default Repositories

Step 1: Update Software Repositories

It’s a good idea to update the local database of software to make sure you’ve got access to the latest revisions.

Open a terminal window and type:

sudo apt-get update

Allow the operation to complete.

Step 2: Uninstall Old Versions of Docker

Next, it’s recommended to uninstall any old Docker software before proceeding.

Use the command:

sudo apt-get remove docker docker-engine docker.io

Step 3: Install Docker on Ubuntu 18.04

To install Docker on Ubuntu, in the terminal window enter the command:

sudo apt install docker.io

Step 4: Start and Automate Docker

The Docker service needs to be setup to run at startup. To do so, type in each command followed by enter:

sudo systemctl start docker
sudo systemctl enable docker
enable docker command, in terminal

Step 5 (Optional): Check Docker Version

To verify the installed Docker version number, enter:

docker --version
checking version of docker installed in terminal

Note: The official Docker website does not offer support for Ubuntu 18.04. It’s possible that the Ubuntu default repositories have not updated to the latest revision. There’s nothing wrong with running this installation. However, if you are up for a slightly more intensive operation, you can install a more recent (or specific) Docker from the official Docker repositories.

Option 2: Install Docker from Official Repository

Step 1: Update Local Database

Update the local database with the command:

sudo apt-get update

Step 2: Download Dependencies

You’ll need to run these commands to allow your operating system to access the Docker repositories over HTTPS.

In the terminal window, type:

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

To clarify, here’s a brief breakdown of each command:

  • apt-transport-https: Allows the package manager to transfer files and data over https
  • ca-certificates: Allows the system (and web browser) to check security certificates
  • curl: This is a tool for transferring data
  • software-properties-common: Adds scripts for managing software

Step 3: Add Docker’s GPG Key

The GPG key is a security feature.

To ensure that the software you’re installing is authentic, enter:

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add –
docker GPG key security in terminal

Step 4: Install the Docker Repository

To install the Docker repository, enter the command:

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

The command “$(lsb_release –cs)” scans and returns the codename of your Ubuntu installation – in this case, Bionic. Also, the final word of the command – stable– is the type of Docker release.

example installation of the docker repository in terminal

A stable release is tested and confirmed to work, but updates are released less frequently. You may substitute edge if you’d like more frequent updates, at the cost of potential instability. There are other repositories, but they are riskier – more info can be found on the Docker web page.     Step 5: Update Repositories  

Update the repositories you just added:

sudo apt-get update

Step 6: Install Latest Version of Docker

To install the latest version of docker:

sudo apt-get install docker-ce

Step 7 (Optional): Install Specific Version of Docker 

List the available versions of Docker by entering the following in a terminal window:

apt-cache madison docker-ce
list available docker version in terminal


The system should return a list of available versions as in the image above.

At this point, type the command:

sudo apt-get install docker-ce=[version]

However, substitute <strong>[version]</strong> for the version you want to install (pulled from the list you just generated).

For example:

installation of a specific version of docker in terminal

Option 3: Install Docker from a .deb Package

You can also install Docker manually by downloading the Docker .deb file.

1. First, navigate to the Docker download page.

2. Next, click on the pool link, then stable, then amd64.  This is the location of the stable Docker releases for Ubuntu 18.04.

stable docker releases index on links

3. Click on the Docker engine you want to install and the .deb package downloads automatically. Make a note of the path where you saved it.

4. To install Docker, run the following command (using the path of the downloaded Docker package):

sudo dpkg -i /path/to/docker.package.deb

Allow the installer to run.

Option 4: Install Docker from a Convenience Script

For installing edge or testing versions of Docker, you can use convenience scripts.

This method should not be used in production environments or if you already have another version of Docker installed on your system.

Make sure to inspect the scripts before downloading and running them on your system.

Install Docker Engine – Community

To install the latest Docker engine, use the get.docker.com script by running the command:

curl -fsSL https://get.docker.com -o get-docker.sh

Run the script to start the installation:

sh get-docker.sh

The Docker service will start automatically.

Note: Using convenience scripts does not allow you to customize installation parameters or choose the Docker version.

Install Docker Testing Version

To install the latest testing version of Docker, use the test.docker.com script:

curl -fsSL https://test.docker.com -o test-docker.sh

Start the installation by running the command:

sh test-docker.sh

Conclusion

Great job!  You’ve got four (4) different options for installing Docker on Ubuntu 18.04.

Finally, you can check the Docker guides if you get into trouble, plus they have a fairly robust forum you can search. Happy developing!

Was this article helpful?
YesNo
Sofija Simic
Sofija Simic is an aspiring Technical Writer at phoenixNAP. Alongside her educational background in teaching and writing, she has had a lifelong passion for information technology. She is committed to unscrambling confusing IT concepts and streamlining intricate software installations.
Next you should read
How To Install Docker Compose On Ubuntu 20.04
September 17, 2020

Docker Compose is used to launch, execute, communicate, and close containers with a single coordinated command. Follow this guide to install Docker Compose on Ubuntu 20.04.
Read more
How To Install Docker On CentOS 8
December 27, 2019

CentOS 8 does not provide official support for Docker. This article clearly shows you how to install a fully functional version of Docker regardless.
Read more
How To Install Docker On Debian 10 Buster
October 28, 2019

Docker is a virtual container management tool that speeds up and improves application development. Created containers share the kernel and other resources, but are also isolated from one another. The software allows you to make hi
Read more
How To Manage Docker Containers? Best Practices
January 29, 2019

With Docker Container Management you can manage complex tasks with few resources. Learn the best practices of Docker Containers.
Read more
  • © 2021 Copyright phoenixNAP | Global IT Services. All Rights Reserved.