09-module-example

Terraform Module example

This folder contains a module example of a Terraform file on AWS (Amazon Web Services).

It shows how to develop (not duplicating code) web server clusters in different environments using a module.

The environments are:

• Staging (stage)
• Production (prod)

This is the file layout:

global
    └── s3/
        ├── main.tf
        └── (etc)

modules
    └── services/
        └── webserver-cluster/
            ├── main.tf
            └── (etc)

stage
    ├── services/
    │   └── webserver-cluster/
    │       ├── main.tf
    │       └── (etc)
    └── data-stores/
        └── mysql/
            ├── main.tf
            └── (etc)

prod
    ├── services/
    │   └── webserver-cluster/
    │       ├── main.tf
    │       └── (etc)
    └── data-stores/
        └── mysql/
            ├── main.tf
            └── (etc)

It uses in common for both environments:

• Terraform Remote State example: global/s3
• Terraform Web Server Cluster module example: modules/services/webserver-cluster

It uses for staging environment:

• Terraform MySQL on RDS example (staging environment): stage/data-stores/mysql
• Terraform Web Server Cluster example (staging environment): stage/services/webserver-cluster

It uses for production environment:

• Terraform MySQL on RDS example (production environment): prod/data-stores/mysql
• Terraform Web Server Cluster example (production environment): prod/services/webserver-cluster

Requirements

• You must have Terraform installed on your computer.
• You must have an AWS (Amazon Web Services) account.
• It uses the Terraform AWS Provider that interacts with the many resources supported by AWS through its APIs.
• This code was written for Terraform 0.10.x.

Using the code

• Configure your AWS access keys.

  Important: For security, it is strongly recommend that you use IAM users instead of the root account for AWS access.

  Setting your credentials for use by Terraform can be done in a number of ways, but here are the recommended approaches:

  • The default credentials file

    Set credentials in the AWS credentials profile file on your local system, located at:

    ~/.aws/credentials on Linux, macOS, or Unix

    C:\Users\USERNAME\.aws\credentials on Windows

    This file should contain lines in the following format:

    [default]
    aws_access_key_id = <your_access_key_id>
    aws_secret_access_key = <your_secret_access_key>

    Substitute your own AWS credentials values for the values <your_access_key_id> and <your_secret_access_key>.

  • Environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY

    Set the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables.

    To set these variables on Linux, macOS, or Unix, use export:

    export AWS_ACCESS_KEY_ID=<your_access_key_id>
    export AWS_SECRET_ACCESS_KEY=<your_secret_access_key>

    To set these variables on Windows, use set:

    set AWS_ACCESS_KEY_ID=<your_access_key_id>
    set AWS_SECRET_ACCESS_KEY=<your_secret_access_key>

• Use Terraform Remote State example for creating the remote state bucket. See: global/s3

• Use Terraform module example for Web Server Cluster example in the staging environment and Web Server Cluster example in the production environment. See: modules/services/webserver-cluster

• Use Terraform MySQL on RDS example for creating a MySQL database in the staging environment. See: stage/data-stores/mysql

• Use Terraform Web Server Cluster example for creating a web server cluster in the staging environment. See: stage/services/webserver-cluster

• Use Terraform MySQL on RDS example for creating a MySQL database in the production environment. See: prod/data-stores/mysql

• Use Terraform Web Server Cluster example for creating a web server cluster in the production environment. See: prod/services/webserver-cluster