Today Docker is quite popular on service deployment. While using Terraform, we can have infra as code to make deployment more efficient.

On ubuntu 20.04, we could have docker and terraform installed easily. Just follow the steps below.

Install Docker

First add the GPG key for the official Docker repository to your system.

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

Then add the Docker repository to APT sources.

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

Update the repository.

 $ sudo apt update
 

Finally install the Docker package.

 $ sudo apt install docker-ce
 

You can check docker's running status by this command.

 $ sudo systemctl status docker
 

It's better to add your linux account to docker group to avoid sudo for running docker.

 $ sudo usermod -aG docker ${USER}
 

Then exit current shell and re-login to make the change above take effect.

The last step, run a docker demo to see if it's going fine.

 $ docker run hello-world
 

Install Terraform

First, download and add the HashiCorp signed gpg keys to your system.

 $ curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo apt-key add -
 

Next, add the HashiCorp repository to the APT source.

 $ sudo add-apt-repository "deb [arch=$(dpkg --print-architecture)] https://apt.releases.hashicorp.com $(lsb_release -cs) main"
 

Update the repository.

 $ sudo apt update
 

Finally, install the program Terraform.

 $ sudo apt install terraform
 

Once Terraform has been installed, verify its version.

 $ terraform -v
 Terraform v1.3.6
 on linux_amd64
 

Run docker via terraform

We can create a terraform script to run docker as follows.

First create a project dir.

 $ mkdir terraform
 $ cd terraform
 

Create the script below, name it "main.tf".

 terraform {
   required_providers {
     docker = {
       source  = "kreuzwerker/docker"
       version = "~> 2.13.0"
     }
   }
 }
   
 provider "docker" {}
   
 resource "docker_image" "nginx" {
   name         = "nginx:latest"
   keep_locally = false
 }
   
 resource "docker_container" "nginx" {
   image = docker_image.nginx.latest
   name  = "tutorial"
   ports {
     internal = 80
     external = 8000
   }
 }
 

Initialize the project, which downloads a plugin that allows Terraform to interact with Docker.

 $ terraform init
 

Provision the NGINX server container with apply.

 $ terraform apply
 

Verify the existence of the NGINX container by visiting hostname:8000 in your web browser.

And docker ps will show that,

 $ docker ps
 CONTAINER ID   IMAGE          COMMAND                  CREATED          STATUS          PORTS                  NAMES
 1b789f59a4d7   ac8efec875ce   "/docker-entrypoint.…"   47 minutes ago   Up 47 minutes   0.0.0.0:8000->80/tcp   tutorial
 

To stop the container, run the following command in project dir.

 $ terraform destroy
 

Now, you have implemented docker and terraform successfully on ubuntu 20.04.

References

How To Install and Use Docker on Ubuntu 20.04

How to Install Terraform on Ubuntu Server 20.04

Terraform Tutorials