gruntwork-io/intro-to-terraform

Sample code for the blog post series "A Comprehensive Guide to Terraform."

NOTE: This repo is now archived and replaced!

This repo contains the sample code for the blog post series A Comprehensive Guide to Terraform, which we turned into the book Terraform: Up & Running, with its own code examples repo.

Instead of maintaining two examples repos, we have decided to maintain just one. This repo is now archived, so please head over to the terraform-up-and-running-code repo for the most up to date examples.

Original content (saved for posterity)

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.

intro-to-terraform's Issues

Update aws_s3_bucket configuration for TF AWS Provider version 4.x

• intro-to-terraform/s3-backend/main.tf

  Line 34 in 1f9a22a

  resource "aws_s3_bucket" "terraform_state" {

Related Issues

https://github.com/gruntwork-io/cloud-chasers/issues/2

Single-web-server raises error

simply running terraform apply in the single-web-server directory raises:

• aws_instance.example: Error launching source instance: VPCResourceNotSpecified: The specified instance type can only be used in a VPC. A subnet ID or network interface ID is required to carry out the request.
  status code: 400, request id: 94b7cfbe...

cluster-of-web servers

I tried to use code for cluster-of-web-servers.
Few resources were created successfully, but not all.

I keep getting this error, do you know why this is happening. It says issue is with configuration not supported.

Error: Error applying plan:

1 error(s) occurred:

• aws_autoscaling_group.example: 1 error(s) occurred:

• aws_autoscaling_group.example: "tf-asg-20190328160913020900000002": Waiting up to 10m0s: Need at least 2 healthy instances in ASG, have 0. Most recent activity: {
  ActivityId: "5cc5a714-61e2-eba7-663b-20124631a347",
  AutoScalingGroupName: "tf-asg-20190328160913020900000002",
  Cause: "At 2019-03-28T16:18:27Z an instance was started in response to a difference between desired and actual capacity, increasing the capacity from 0 to 2.",
  Description: "Launching a new EC2 instance. Status Reason: The requested configuration is currently not supported. Please check the documentation for supported configurations. Launching EC2 instance failed.",
  Details: "{"Availability Zone":"us-west-1a"}",
  EndTime: 2019-03-28 16:18:29 +0000 UTC,
  Progress: 100,
  StartTime: 2019-03-28 16:18:29.178 +0000 UTC,
  StatusCode: "Failed",
  StatusMessage: "The requested configuration is currently not supported. Please check the documentation for supported configurations. Launching EC2 instance failed."
  }

Thanks,
Alok

cluster server issue

Hi,
I'm new to terraform and have been following your guide. I've got the single webserver code running but when I try and run the cluster web servers, I get the following errors. I'm pretty sure I've missed something out!

cluster-of-web-servers]$ terraform plan
Error configuring: 2 error(s) occurred:

• aws_autoscaling_group.example: missing dependency: data.aws_availability_zones
• aws_elb.example: missing dependency: data.aws_availability_zones

Can you point me in the right direction please? I did a git clone, set my own access/secret key and ran the terraform plan.

Regards

Can't see how you're incorporating the S3 backend

Hi,
Great blogs, they have been extremely helpful!

I might be missing something in your example tree here, but I do not see how you are using the S3 backend in any of the examples?

Thanks

Syntax error in blog post?

I was experimenting with workspaces in https://blog.gruntwork.io/how-to-manage-terraform-state-28f5697e68fa (great set of blog posts btw, thanks!) and tried this piece of code:

resource "aws_instance" "example" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = 
    terraform.workspace == "default" 
    ? "t2.medium" 
    : "t2.micro"
}

which gave me an error:

Error: Argument or block definition required

on main.tf line 29, in resource "aws_instance" "example":
29: terraform.workspace == "default"

An argument or block definition is required here. To set an argument, use the
equals sign "=" to introduce the argument value.

Modifying the above code to this fixed my issue:

resource "aws_instance" "example" {
    ami           = "ami-0c55b159cbfafe1f0"
    instance_type = "${
        terraform.workspace == "default"
        ? "t2.medium"
        : "t2.micro"
    }"
}