Day 2 Terra-week Challange

Task 1: Familiarize yourself with HCL syntax used in Terraform

HCL (HashiCorp Configuration Language) is the syntax used in Terraform for defining infrastructure as code. Here's a breakdown of some key concepts:

1. Blocks: In HCL, configurations are organized into blocks. Each block represents a particular construct in Terraform, such as resources, providers, variables, etc. Blocks are identified by their type and enclosed in braces {}.

2. Parameters and Arguments: Within blocks, you define parameters and arguments. Parameters are predefined by Terraform and specify the configuration of the block, while arguments are user-defined values provided to these parameters.

3. Resources: Resources represent infrastructure components such as virtual machines, networks, databases, etc., that you want to manage with Terraform. They are defined using the resource block and are associated with a specific provider.

4. Data Sources: Data sources allow Terraform to fetch information from existing infrastructure or services. They are defined using the data block and can retrieve information like AMI IDs, IP addresses, etc.

Task 2: Understand variables, data types, and expressions in HCL

• Variables: Represent placeholders for values that can change between environments or deployments. You define them in separate .tf files (e.g., variables.tf).

• Data Types: HCL supports various data types like strings, numbers, booleans, lists, and maps to store and manipulate data.

• Expressions: HCL allows you to perform calculations, comparisons, and string manipulation using operators and functions.

Example: Using Variables in Terraform Configuration

1. Create variables.tf:

variable "local_file_name" {
  type = string
  default = "config.txt"
}

2. Create main.tf:

variable "local_file_name" {
  type = string
  default = "config.txt"
}

Explanation:

• variables.tf defines a variable local_file_name with a default value of "config.txt".

• main.tf references the variable using var.local_file_name within the local_file resource's filename argument.

Task 3: Hands-on with Terraform Configuration

• Required Providers: Terraform interacts with cloud providers and services through providers. You specify them in the required_providers block within your configuration.

Example: Using Docker Provider

terraform {
  required_providers {
    docker = {
      source  = "hashicorp/docker"
      version = "~> 2.0"
    }
  }
}

resource "docker_image" "my_image" {
  name          = "my-custom-image"
  build_context = "./dockerfiles/my-image"
}

Explanation:

• We define the docker provider with its source and version.

• The docker_image resource creates a custom Docker image using the specified build context.

Testing Your Configuration

1. Initialize Terraform: terraform init (Downloads required providers)

2. Validate your configuration: terraform validate (Checks syntax and provider compatibility)

3. Preview your changes (optional): terraform plan (Shows what Terraform will create/modify)

4. Apply the configuration (optional): terraform apply (Executes the plan)