Docker Containers w/ Terraform¶

Table of Contents¶

Deploy Docker Containers with Terraform
Setting Up Terraform
Project Setup
Creating a Deployment
Deploy 3 containers that are bound internally on port 80 and externally use 8080, 8081, and 8082.
tl;dr

Setting Up Terraform¶

Your team has decided to use Terraform and deploy containers in an infrastructure as code manner. Verify that containerd is running and that Terraform is installed on your system.

sudo systemctl status containerd
The build infrastructuredocs

Project Setup¶

Make sure all the prerequisites are met.

containerd is running
terraform is installed

Check that containerd is running and exposed on your system¶

systemctl status containerd --no-pager
ss -ntulp | grep -i containerd

Check that Terraform is installed on your system¶

which terraform
terraform version

Make a Directory for your Terraform Project Files¶

sudo mkdir /root/learn-terraform-docker-container
cd /root/learn-terraform-docker-container/

Make sure there are no other Docker containers running¶

docker ps -a
docker images

Creating a Deployment¶

Let's create the first deployment of Terraform in our environment.

Create a Terraform configuration for running nginx on port 8000 on your system.
Verify that you can see the running container.
View your terraform.tfstate file to see what Terraform tracks in a configuration deployment.

Make a main.tf file in the directory
```
touch main.tf
```

Add a default configuration for the terraform project

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
  }
}

Make sure the Terraform configuration is well formatted and validated.
```
terraform fmt
terraform validate
```

We will see an error here. This is because the validate is looking to see if we've done an init and pulled down the provider. That is happening in the next step.

Before we can deploy with Terraform we need to initialize and download all providers.
```
terraform init
```
Let's check the system to see all the files that have been created
```
ls -al
```
Let's deploy our resources
```
terraform apply --auto-approve
```

Let's verify that we have a working container

docker images
docker ps
curl 127.0.0.1:8000

Look at the terraform.tfstate file to see all the objects that terraform is tracking in the deployment.
```
cat terraform.tfstate
```
WARNING: The terraform.tfstate file should never be edited by hand, only terraform should edit that file.

Your team is very impressed that you were able to deploy one container with Terraform and Docker. Now they want you to deploy multiple containers for different ports on the system.

Deploy 3 Containers¶

Deploy 3 containers that are bound internally on port 80 and externally use 8080, 8081, and 8082.

Start by destroying our old Terraform configuration.
```
terraform destroy --auto-approve
```

Then edit for our new configuration.

vi main.tf

Set the configuration to look like this:

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" "nginx8080" {
  image = docker_image.nginx.latest
  name  = "nginx8080"
  ports {
    internal = 80
    external = 8080
  }
}

resource "docker_container" "nginx8081" {
  image = docker_image.nginx.latest
  name  = "nginx8081"
  ports {
    internal = 80
    external = 8081
  }
}

resource "docker_container" "nginx8082" {
  image = docker_image.nginx.latest
  name  = "nginx8082"
  ports {
    internal = 80
    external = 8082
  }
}

Make sure the Terraform configuration is well formatted and validated.
```
terraform fmt
terraform validate
```
Deploy our resources
```
terraform apply --auto-approve
```

Verify that all the containers are working.

docker images
docker ps
curl 127.0.0.1:8080
sleep 2
curl 127.0.0.1:8081
sleep 2
curl 127.0.0.1:8082

tl;dr¶

Check that containerd is running and exposed (i.e., listening) on your system.

sudo systemctl status containerd --no-pager
ss -ntulp | grep -i containerd

Check that terraform is installed.
```
which terraform
terraform version
```
Create a directory named learn-terraform-docker-container.
```
mkdir learn-terraform-docker-container
```
Change into the directory.
```
cd learn-terraform-docker-container
```
Create a main.tf file to define your infrastructure.
```
touch main.tf
```

Set a configuration in main.tf

terraform {
  required_providers {
    docker = {
      source = "kreuzwerker/docker"
      version = "~> 3.0.1"
    }
  }
}

provider "docker" {}

resource "docker_image" "nginx" {
  name         = "nginx:latest"
  keep_locally = false
}

resource "docker_container" "nginx" {
  image = docker_image.nginx.image_id
  name  = "tutorial"
  ports {
    internal = 80
    external = 8000
  }
}