Errata

On Chapter 5:
Below the sentence,
"You can also use for expressions to output a map rather than a list using the following syntax:",

It shows:
# For looping over lists
{for <ITEM> in <MAP> : <OUTPUT_KEY> => <OUTPUT_VALUE>}

# For looping over maps
{for <KEY>, <VALUE> in <MAP> : <OUTPUT_KEY> => <OUTPUT_VALUE>}

--------------------------------------------
I believe, it is supposed to be:
# For looping over lists
[for <ITEM> in <MAP> : <OUTPUT_KEY> => <OUTPUT_VALUE>]

# For looping over maps
{for <KEY>, <VALUE> in <MAP> : <OUTPUT_KEY> => <OUTPUT_VALUE>}


as [ ] is for list and { } is for map.

Note from the Author or Editor:
I'll fix this in master

In the section "Loops with for_each Expressions" of Chapter 5, a code snippet for the module "webserver_cluster" in which the new "custom_tags" section is added includes the statement:

enable_autoscaling = true

Running the subsequent "terraform apply" with this statement errors out as the variable is unexpected in the module definition at that point. "enable_autoscaling" is not actually defined until later in the chapter, in the section "Conditionals with the count Parameter."

Commenting out or removing the "enable_autoscaling = true" line from the snippet allows "terraform apply" to run successfully.

Note from the Author or Editor:
I'll fix this in master

The initial alb_example_test.go and other tests generate a "not enough arguments" error, as the function signatures for all of http_helper.HttpGet* functions were changed in terratest v0.19.0 to include a pointer to a TLSConfig struct as the third parameter.

Adding a reference to a new, empty TLSConfig struct in all of the http_helper.HttpGet* functions allows the tests to compile successfully. For example:

http_helper.HttpGetWithRetry(
t,
url,
&tls.Config{},
expectedStatus,
expectedBody,
maxRetries,
timeBetweenRetries,
)

"crypto/tls" also needs to be added to the import list accordingly.

Note from the Author or Editor:
I will fix this in master

The initial run of TestHelloWorldAppExample fails because the expected response body is:

Hello, World

However, the user-data.sh script in the hello-world-app module used up to now (and in the github source repo) is generating formatted output that doesn't match:

<h1>Hello, World</h1>
<p>DB address: mock-value-for-test</p>
<p>DB port: 3306</p>

To fix the problem, either the user-data.sh script can be modified to store only the server_text value in index.html, or the expectedBody value in the test can be changed to match in a variety of ways:

serverText := "Hello, World"
mysqlAddress := "mock-value-for-test"
mysqlPort := 3306
...
expectedBody := fmt.Sprintf("<h1>%s</h1>\n<p>DB Address: %s</p>\n<p>DB Port: %d</p>", serverText, mysqlAddress, mysqlPort)

Note from the Author or Editor:
I will fix this in master.

The maximum number of tests run in parallel is limited by default to the value of CPUs available (the value of GOMAXPROCS), so running the example as-is:

go test -v -timeout 30m

on a system with a default GOMAXPROCS value of 1 (eg., a 1 CPU/1 core VM) will run the tests serially instead of in parallel.

This can be fixed without changing the system's properties by either manually setting a GOMAXPROCS environment variable to something greater than 1:

export GOMAXPROCS=2

or by adding the "-parallel" flag to "go test" with a value greater than 1:

go test -v -timeout 30m -parallel 2

Serial test behavior on a multi-CPU system can be forced by setting GOMAXPROCS or the parallel flag explicitly to 1.

Note from the Author or Editor:
I've updated the book with a note about this

resource "aws_lb_listener_rule" "asg" { listener_arn = aws_lb_listener.http.arn priority = 100

condition {
field = "path-pattern"
values = ["*"]
}

The above path-pattern is deprecated. Updated code:

condition {
path_pattern {
values = ["*"]
}
}

Note from the Author or Editor:
I fixed this issue in the code in multiple places and pushed the fix to master branch (commit ID: ed7aac8).

The official documentation for Chef Provisioning is no longer available in https://docs.chef.io/provisioning.html as it was officially end-of-life according to
https://github.com/chef-boneyard/chef-provisioning

Note from the Author or Editor:
This is correct. This link/mention will need to be removed.

Despite the presence of the example, there is no mention that the launch configuration does not support tags. The only replacements mentioned are ami with image_id and vpc_security_group with security_groups.

Note from the Author or Editor:
Update this sentence:


"The aws_launch_configuration resource uses almost exactly the same parameters as the aws_instance resource (two of the parameters have different names: ami is now image_id and vpc_security_group_ids is now security_groups), so you can cleanly replace the latter with the former:"


To:


"The aws_launch_configuration resource uses almost the same parameters as the aws_instance resource, although it doesn't support tags (we'll handle these in the aws_autoscaling_group resource later) and two of the parameters have different names (ami is now image_id and vpc_security_group_ids is now security_groups), so replace aws_instance with aws_launch_configuration as follows:"

The terraform definition to create the MySQL instance works fine but if you later on try to delete the RDS MySQL server you will get an error because the final snapshot name has not been set.

The easiest & quickest way I found to resolve this is to set the property skip_final_snapshot to true so that the RDS server can be deleted without the need to take a final backup

Note from the Author or Editor:
This is correct. I've updated the 3rd edition of the book to make it clearer that skip_final_snapshot should be set to true.

If you run the plan command on the preceding code, you will see that Terraform
wants to create three IAM users, each with a different name ("neo", "morpheus",
"trinity"):


should be:

If you run the plan command on the preceding code, you will see that Terraform
wants to create three IAM users, each with a different name ("neo.0", "neo.1",
"neo.2"):

Note from the Author or Editor:
Replace:

("neo", "morpheus", "trinity"):

With:

("neo.0", "neo.1", "neo.2"):

The actual code produces:

bios = [
"morpheus is the mentor",
"neo is the hero",
"trinity is the love interest",
]


The book has:

map_example = [
"morpheus is the mentor",
"neo is the hero",
"trinity is the love interest",
]

Note from the Author or Editor:
"map_example" should be replaced with "bios"

The updated Handlers class now handles the /web-service URL by calling a new
method call web_service, which makes an HTTP GET

should be

The updated Handlers class now handles the /web-service URL by making an HTTP GET..."

Note from the Author or Editor:
Original sentence:

"The updated Handlers class now handles the /web-service URL by calling a new method call web_service, which makes an HTTP GET to example.org and proxies the response."

Needs to be updated to:

"The updated Handlers class now handles the /web-service URL by making an HTTP GET to example.org and proxying the response."

bucketRegionForTesting := "YOUR_S3_BUCKET_FOR_TESTING"

should be

bucketRegionForTesting := "YOUR_S3_BUCKET_REGION_FOR_TESTING"

so that the only things that execute are terraform apply and the validations
for the hello-world-app module:

should be :

so that the only things that execute are deploy app and the validations
for the hello-world-app module:

Note from the Author or Editor:
Replace "terraform apply" with "deploy app"

The dependency graph has twice "aws_security_group.instance", where it should instead have "aws_instance.example" and "aws_security_group.instance". This is what I get when I copy/paste the DOT output from the book into Graphviz online.

Note from the Author or Editor:
Figure 2-7 does indeed have a mistake. There are two boxes that both say "aws_security_group.instance" whereas the top one of those boxes should actually say "aws_instance.example"

"one to tow weeks"

Brikman, Yevgeniy. Terraform: Up & Running (Kindle Location 4231). O'Reilly Media. Kindle Edition.

Note from the Author or Editor:
Thanks for reporting! We'll get this typo fixed.