Errata

in chapter 3 configuring remote config.

terraform remote config is no longer present in terraform 0.9 and newer. Instead create a new file (name doesn\t matter) with the following:

terraform {
backend "s3" {
bucket = "terraform-up-and-running-state" #use your bucket
key = "global/s3/terraform.tfstate"
region = "us-east-1"
}
}

then run "terraform init" and it'll ask you to verify if you want to store your state in s3

Note from the Author or Editor:
This is correct. Terraform 0.9 completely changed how remote state is handled. This will require a few changes throughout the book.

Two small mistakes:
1) Page 41 - Piece of code after figure 1-1 missing instructions to install «git»: sudo apt-get install git-all
2) Page 43 - Similar piece of code is missing in the part showing ansible’s code

Note from the Author or Editor:
In code/bash/01-why-terraform/setup-webserver.sh, just above line 16 ("Copy the code from the repository"), add the following:

# Install git
sudo apt-get install -y git-all

In code/ansible/01-why-terraform/webserver.yml, just above line 13 ("Copy the code from the repository), add the following:

- name: Install Git
apt:
name: git-all

Terragrunt certainly deserves a strong highlight in a book about Terraform. But it certainly is not central enough to Terraform to be part of _every single_ example (it's not even part of the standard distribution). Being the main committer of the tool, it's natural that you show some love for your baby :). Still, please step back a little and remove further Terragrunt references after it's (neatly) introduced.
Thanks for your book, looking forward for the next chapters !

Note from the Author or Editor:
This is a very good point. I introduced Terragrunt in chapter three and since I kept evolving the same set of examples for the rest of the book, Terragrunt kept coming up again and again even though it wasn't necessary to any of the examples in later chapters. I've gone back and cleaned it up so now it only shows up in Chapter 3. Thanks!

The folder structure in Figure 6-3 has a minor mistake. It shows:

modules > vpc > vars.tf > outputs.tf and main.tf

The vars.tf should actually be a file and not a folder. That is, the structure should be:

modules > vpc > vars.tf, outputs.tf, and main.tf

should be "tags", not "tag":

resource "aws_instance" "example" {
ami = "ami-2d39803a"
instance_type = "t2. micro"
tag { name = "terraform-example" } <-!!! typo
}

resource "aws_instance" "example" {
ami = "ami-2d39803a"
instance_type = "t2. micro"
tags { name = "terraform-example" } <-!!! correct
}

Note from the Author or Editor:
All fixed, thanks!

in order for the tag to appear as the ec2 instance name, it should be "Name", not "name":
resource "aws_instance" "example" {
ami = "ami-2d39803a"
instance_type = "t2. micro"
tags { Name = "terraform-example" } <-
}

Note from the Author or Editor:
Fixed, thanks!

Although the parameter name for ASG on AWS Console is "Desired", and the book mentions use of "desired_size", the actual corresponding argument/parameter name for Terraform's "aws_autoscaling_group" resource is "desired_capacity"

Note from the Author or Editor:
You're absolutely right. Fixed now. Thanks!

(Working from the Kindle edition which has no page numbers. I put the "location" in the field above.)

This no longer appears to be an issue starting with 0.9.x, at least in the majority of use cases (see caveats below).

in `variables.tf`:
data "aws_availability_zones" "available" {}

in `vpc.tf`:
resource "aws_subnet" "public" {
count = "${length(data.aws_availability_zones.available.names)}"
vpc_id = "${aws_vpc.default.id}"
cidr_block = "10.0.20${count.index}.0/24"
availability_zone = "${element(data.aws_availability_zones.available.names, count.index)}"
map_public_ip_on_launch = true

tags = {
Name = "Public ${element(data.aws_availability_zones.available.names, count.index)}"
Tier = "public"
}
}

This produces flawless results.

Results may not be exactly as expected if you try to `terraform apply` along with the `-target` parameter.

Note from the Author or Editor:
As of Terraform 0.9, data sources can now be used in the count parameter, but other types of dynamic data (e.g. resources) still cannot. I will need to update this section of the book, along with several other changes, as a result of this new Terraform release.