theinformationlab/intro-to-terraform

Sample code for the blog post "An Introduction to Terraform"

An Introduction to Terraform Sample Code

This repo contains the sample code for the blog post series A Comprehensive Guide to Terraform. The examples correspond to the following parts of the series:

1. An Introduction to Terraform
   • single-web-server: Deploy a single EC2 Instance with a web server that will return "Hello, World" for every request on port 8080.
   • cluster-of-web-servers: Deploy a cluster of EC2 Instances in an Auto Scaling Group (ASG) and an Elastic Load Balancer (ELB). The ELB listens on port 80 and distributes load across the EC2 Instances, each of which runs the same "Hello, World" web server.
2. How to Manage Terraform State
   • s3-backend: Create an S3 bucket and DynamoDB table to use as a Terraform backend.
   • database: Deploy MySQL on top of Amazon's Relational Database Service (RDS).
3. How to create reusable infrastructure with Terraform modules
   • modules: Examples of reusable Terraform modules, including a module that can deploy a web server cluster on top of ASG with an ELB.
   • live: Examples of how to deploy different live environments (i.e., staging, production) using the code from the modules folder.
4. Terraform tips & tricks: loops, if-statements, and pitfalls
   • loops-with-count: Examples of how to use the count parameters to "loop" over resources.
   • loops-with-for-each: Examples of how to use for_each to "loop" over inline blocks.
   • loops-with-for: Examples of how to use for to "loop" over individual values.

Quick start

Note: These examples deploy resources into your AWS account. Although all the resources should fall under the AWS Free Tier, it is not our responsibility if you are charged money for this.

1. Install Terraform.
2. Set your AWS credentials as the environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY.
3. cd into one of the example folders.
4. Run terraform init.
5. Run terraform apply.
6. After it's done deploying, the example will output URLs or IPs you can try out.
7. To clean up and delete all resources after you're done, run terraform destroy.

License

Please see LICENSE.txt for details on how the code in this repo is licensed.