Auto generate backend key based on component name for azurerm

[lukeorellana]

what

When using the AzureRM backend type, automatically generate backend key based on component name if the backend key is not specified at the component level:

• Key is created in {Global Backend Key value}/{component name}.terraform.tfstate format. Places all component states in a storage account folder with the name of the global backend key value.
• If the key is specified at the component level, the backend key is not automatically generated.

Before:

terraform:
  backend_type: azurerm
  backend:
    azurerm:
      subscription_id: 88888-8888-8888-8888-8888888888
      resource_group_name: rg-terraform-state
      storage_account_name: staterraformstate
      container_name: dev-tfstate

components:
  terraform:
    "monitoring":
      backend:
          azurerm:
            key: dev.atmos/monitoring.terraform.tfstate
        
    "networking":
      backend:
          azurerm:
            key: dev.atmos/networking.terraform.tfstate

After:

terraform:
  backend_type: azurerm
  backend:
    azurerm:
      subscription_id: 88888-8888-8888-8888-8888888888
      resource_group_name: rg-terraform-state
      storage_account_name: staterraformstate
      container_name: dev-tfstate
      key: dev.atmos

components:
  terraform:
    "rg": {}

    "monitoring": {}

    "vault": {}

backend.tf:

{
  "terraform": {
    "backend": {
      "azurerm": {
        "subscription_id": "88888-8888-8888-8888-8888888888",
        "container_name": "dev-tfstate",
        "key": "dev.atmos/rg.terraform.tfstate",
        "resource_group_name": "rg-terraform-state",
        "storage_account_name": "staterraformstate"
      }
    }
  }
}

why

The (azure backend) does not currently have a prefix option for workspaces. When using Atmos with Azure, users are forced to specify each backend key for every component.

references

hashicorp/terraform#28985

[aknysh]

@lukeorellana thanks for the PR, and thanks for trying out atmos.
The PR looks, good, would yuo please add an example of the backend here https://github.com/cloudposse/atmos/blob/master/examples/complete/stacks/globals/globals.yaml#L7

backend_type: s3 # s3, remote, vault, static, azurerm, etc.

azurerm:
      subscription_id: 88888-8888-8888-8888-8888888888
      resource_group_name: rg-terraform-state
      storage_account_name: staterraformstate
      container_name: dev-tfstate
      key: dev.atmos

so other people would see the example on how to use it.

thanks!

[aknysh]

@lukeorellana thanks you, please see comments

[lukeorellana]

@aknysh Thanks! Pushed commit with backend example . Let me know if you would like me to add anything else.

[aknysh]

Suggested change

[aknysh]

Suggested change

	// The backend state file will be formated like so: {global key name}/{component name}.terraform.tfstate
	// The backend state file will be formatted like so: {global key name}/{component name}.terraform.tfstate

[aknysh]

thanks @lukeorellana