Welcome back to another day of our 90 days of DevOps journey! Today, we're diving deeper into the realms of infrastructure as code (IaC) with Terraform and exploring the integration with Docker. Specifically, we'll be looking at blocks and resources in Terraform and how they play a crucial role in managing Docker containers.

Understanding Blocks and Resources in Terraform

In Terraform, configuration files are composed of blocks and resources. Let's break down what these terms mean:

Blocks:

Blocks in Terraform are sections of configuration grouped together based on their functionality. They serve as containers for other elements like resources, data sources, providers, etc. Blocks are defined by their type, for instance, terraform, provider, resource, etc., and they enclose related configurations within curly braces {}.

Resources:

Resources in Terraform represent the infrastructure components that you want to manage. These can be virtual machines, networks, databases, or in our case, Docker containers. Each resource block defines a specific instance of a particular infrastructure component along with its configuration settings.

Task 01: Creating a Terraform Script with Blocks and Resources

Let's get our hands dirty by creating a Terraform script that utilizes blocks and resources to manage Docker containers.

terraform {
  required_providers {
    docker = {
      source  = "kreuzwerker/docker"
      version = "~> 2.21.0"
    }
  }
}

# Task 02: Docker Resource Blocks

# Resource block for Docker image
resource "docker_image" "nginx" {
  name         = "nginx:latest"
  keep_locally = false
}

# Resource block for running a Docker container for nginx
resource "docker_container" "nginx" {
  image = docker_image.nginx.latest
  name  = "tutorial"
  ports {
    internal = 80
    external = 80
  }
}

In this script:

• We've specified the required Docker provider with its version.

• We've created a resource block for pulling the nginx:latest Docker image.

• We've defined another resource block for running a Docker container named "tutorial" based on the nginx image, exposing port 80 internally and externally.

With this Terraform script, we can easily manage Docker containers as part of our infrastructure with predictable and repeatable deployments.

Conclusion

Today, we delved into the concepts of blocks and resources in Terraform and put them into practice by managing Docker containers using Terraform. Understanding how to structure your Terraform configurations with blocks and resources is essential for maintaining clean and manageable infrastructure as code.

Join me tomorrow as we explore more exciting tools and practices on our DevOps journey! Keep coding, automating, and building resilient infrastructure! Until then, happy DevOps-ing! 👩‍💻🚀