Conditional Expressions/Fxns

Question 1

What are conditional expressions in terraform?

Answer 1

They allow you to choose between two values based on a condition

Question 2

Whats the syntax of conditional expressions in Terraform?

Answer 2

condition ? true_val : false_val

Ex: instance_type = var.environment == “dev” ? “t2.micro” : “m5.large”

Question 3

What conditions can you use in Terraform?

Answer 3

== Equal to
!= Not Equal to
&& - Both conditions have to be true

Ex: instance_type = var.environment == “prod” && var.region == “us-east-1” ? m5.large : t2.micro

Question 4

What is passed to the lookup function in Terraform and what does it expect?

Answer 4

The lookup () function requires that you first pass a map variable followed by a key.

Ex. ami = lookup (var.ami, var.region)
*where var.ami is a map variable with key/value pairs and var.region is the key passed.

Question 5

If a key passed to a lookup function doesn’t match a value in the map variable, what does the lookup function return

Answer 5

The default value

Question 6

How does the length function work in Terraform?

Answer 6

It determines the length of a given list, map, or string

Ex:
length ([“first”,”second”]
Answer = 2

> length({“a” = “b”})
1
length(“hello”)
5

Question 7

How does the element function work?

Answer 7

The element function retrieves a single element from the list

Ex:
> element([“a”, “b”, “c”], 1)
b, since the first element in a list is 0

Question 8

How does the formatdate () function work?

Question 9

How does the timestamp() function work?

Answer 9

It returns a UTC timestamp string in RFC 3339 format

Ex
> timestamp()
2018-05-13T07:44:12Z