Sometimes we notice that the name of certain output is not appropriate anymore, however, since we have to ensure forward compatibility in the same major version, its name MUST NOT be changed directly. It MUST be moved to an independent deprecated_outputs.tf file, then redefine a new output in output.tf and make sure it’s compatible everywhere else in the module.

Expressions in locals block MUST be arranged alphabetically.

Good examples:

locals {
  name = coalesce(var.name, "name")
  tags = merge(var.tags, {
    env = "prod"
  })
}

locals {
  tags = merge(var.tags, {
    env = "prod"
  })
}

locals {
  name = coalesce(var.name, "name")
}

A toggle variable MUST be used to allow users to avoid the creation of a new resource block by default if it is added in a minor or patch version.

Potential breaking(surprise) changes introduced by resource block

1. Adding a new resource without count or for_each for conditional creation, or creating by default
2. Adding a new argument assignment with a value other than the default value provided by the provider’s schema
3. Adding a new nested block without making it dynamic or omitting it by default
4. Renaming a resource block without one or more corresponding moved blocks
5. Change resource’s count to for_each, or vice versa

Terraform moved block could be your cure.

Module owners MUST use lower snake_casing for naming the following:

• Locals
• Variables
• Outputs
• Resources (symbolic names)
• Modules (symbolic names)

For example: snake_casing_example (every word in lowercase, with each word separated by an underscore _)

Module owners MUST use the below tooling for unit/linting/static/security analysis tests. These are also used in the AVM Compliance Tests.

• Terraform test
  • terraform <validate/fmt/test>
• tflint (with azurerm ruleset)
• Go
  • Some tests are provided as part of the AVM Compliance Tests, but you are free to also use Go for your own tests.

We can use count and for_each to deploy multiple resources, but the improper use of count can lead to anti pattern .

You can use count to create some kind of resources under certain conditions, for example: