feat: Added wrappers automatically generated via pre-commit hook (#271)

Author: antonbabenko

.github/workflows/pre-commit.yml

@@ -71,6 +71,14 @@ jobs:
         id: minMax
         uses: clowdhaus/terraform-min-max@v1.0.3
 
+      - name: Install hcledit (for terraform_wrapper_module_for_each hook)
+        shell: bash
+        run: |
+          curl -L "$(curl -s https://api.github.com/repos/minamijoyo/hcledit/releases/latest | grep -o -E -m 1 "https://.+?_linux_amd64.tar.gz")" > hcledit.tgz
+          sudo tar -xzf hcledit.tgz -C /usr/bin/ hcledit
+          rm -f hcledit.tgz 2> /dev/null
+          hcledit version
+
       - name: Pre-commit Terraform ${{ steps.minMax.outputs.maxVersion }}
         uses: clowdhaus/terraform-composite-actions/pre-commit@v1.3.0
         with:

.pre-commit-config.yaml

@@ -1,8 +1,9 @@
 repos:
   - repo: https://github.com/antonbabenko/pre-commit-terraform
-    rev: v1.64.0
+    rev: v1.71.0
     hooks:
       - id: terraform_fmt
+      - id: terraform_wrapper_module_for_each
       - id: terraform_validate
       - id: terraform_docs
         args:
@@ -23,7 +24,7 @@ repos:
           - '--args=--only=terraform_standard_module_structure'
           - '--args=--only=terraform_workspace_remote'
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.1.0
+    rev: v4.2.0
     hooks:
       - id: check-merge-conflict
       - id: end-of-file-fixer

README.md

@@ -81,6 +81,12 @@ module "ec2_instance" {
 }
 ```
 
+## Module wrappers
+
+Users of this Terraform module can create multiple similar resources by using [`for_each` meta-argument within `module` block](https://www.terraform.io/language/meta-arguments/for_each) which became available in Terraform 0.13.
+
+Users of Terragrunt can achieve similar results by using modules provided in the [wrappers](https://github.com/terraform-aws-modules/terraform-aws-ec2-instance/tree/master/wrappers) directory, if they prefer to reduce amount of configuration files.
+
 ## Examples
 
 - [Complete EC2 instance](https://github.com/terraform-aws-modules/terraform-aws-ec2-instance/tree/master/examples/complete)

wrappers/README.md

@@ -0,0 +1,100 @@
+# Wrapper for the root module
+
+The configuration in this directory contains an implementation of a single module wrapper pattern, which allows managing several copies of a module in places where using the native Terraform 0.13+ `for_each` feature is not feasible (e.g., with Terragrunt).
+
+You may want to use a single Terragrunt configuration file to manage multiple resources without duplicating `terragrunt.hcl` files for each copy of the same module.
+
+This wrapper does not implement any extra functionality.
+
+## Usage with Terragrunt
+
+`terragrunt.hcl`:
+
+```hcl
+terraform {
+  source = "tfr:///terraform-aws-modules/ec2-instance/aws//wrappers"
+  # Alternative source:
+  # source = "git::git@github.com:terraform-aws-modules/terraform-aws-ec2-instance.git?ref=master//wrappers"
+}
+
+inputs = {
+  defaults = { # Default values
+    create = true
+    tags = {
+      Terraform   = "true"
+      Environment = "dev"
+    }
+  }
+
+  items = {
+    my-item = {
+      # omitted... can be any argument supported by the module
+    }
+    my-second-item = {
+      # omitted... can be any argument supported by the module
+    }
+    # omitted...
+  }
+}
+```
+
+## Usage with Terraform
+
+```hcl
+module "wrapper" {
+  source = "terraform-aws-modules/ec2-instance/aws//wrappers"
+
+  defaults = { # Default values
+    create = true
+    tags = {
+      Terraform   = "true"
+      Environment = "dev"
+    }
+  }
+
+  items = {
+    my-item = {
+      # omitted... can be any argument supported by the module
+    }
+    my-second-item = {
+      # omitted... can be any argument supported by the module
+    }
+    # omitted...
+  }
+}
+```
+
+## Example: Manage multiple S3 buckets in one Terragrunt layer
+
+`eu-west-1/s3-buckets/terragrunt.hcl`:
+
+```hcl
+terraform {
+  source = "tfr:///terraform-aws-modules/s3-bucket/aws//wrappers"
+  # Alternative source:
+  # source = "git::git@github.com:terraform-aws-modules/terraform-aws-s3-bucket.git?ref=master//wrappers"
+}
+
+inputs = {
+  defaults = {
+    force_destroy = true
+
+    attach_elb_log_delivery_policy        = true
+    attach_lb_log_delivery_policy         = true
+    attach_deny_insecure_transport_policy = true
+    attach_require_latest_tls_policy      = true
+  }
+
+  items = {
+    bucket1 = {
+      bucket = "my-random-bucket-1"
+    }
+    bucket2 = {
+      bucket = "my-random-bucket-2"
+      tags = {
+        Secure = "probably"
+      }
+    }
+  }
+}
+```

wrappers/main.tf

@@ -0,0 +1,57 @@
+module "wrapper" {
+  source = "../"
+
+  for_each = var.items
+
+  create                               = try(each.value.create, var.defaults.create, true)
+  name                                 = try(each.value.name, var.defaults.name, "")
+  ami                                  = try(each.value.ami, var.defaults.ami, "")
+  associate_public_ip_address          = try(each.value.associate_public_ip_address, var.defaults.associate_public_ip_address, null)
+  availability_zone                    = try(each.value.availability_zone, var.defaults.availability_zone, null)
+  capacity_reservation_specification   = try(each.value.capacity_reservation_specification, var.defaults.capacity_reservation_specification, null)
+  cpu_credits                          = try(each.value.cpu_credits, var.defaults.cpu_credits, null)
+  disable_api_termination              = try(each.value.disable_api_termination, var.defaults.disable_api_termination, null)
+  ebs_block_device                     = try(each.value.ebs_block_device, var.defaults.ebs_block_device, [])
+  ebs_optimized                        = try(each.value.ebs_optimized, var.defaults.ebs_optimized, null)
+  enclave_options_enabled              = try(each.value.enclave_options_enabled, var.defaults.enclave_options_enabled, null)
+  ephemeral_block_device               = try(each.value.ephemeral_block_device, var.defaults.ephemeral_block_device, [])
+  get_password_data                    = try(each.value.get_password_data, var.defaults.get_password_data, null)
+  hibernation                          = try(each.value.hibernation, var.defaults.hibernation, null)
+  host_id                              = try(each.value.host_id, var.defaults.host_id, null)
+  iam_instance_profile                 = try(each.value.iam_instance_profile, var.defaults.iam_instance_profile, null)
+  instance_initiated_shutdown_behavior = try(each.value.instance_initiated_shutdown_behavior, var.defaults.instance_initiated_shutdown_behavior, null)
+  instance_type                        = try(each.value.instance_type, var.defaults.instance_type, "t3.micro")
+  ipv6_address_count                   = try(each.value.ipv6_address_count, var.defaults.ipv6_address_count, null)
+  ipv6_addresses                       = try(each.value.ipv6_addresses, var.defaults.ipv6_addresses, null)
+  key_name                             = try(each.value.key_name, var.defaults.key_name, null)
+  launch_template                      = try(each.value.launch_template, var.defaults.launch_template, null)
+  metadata_options                     = try(each.value.metadata_options, var.defaults.metadata_options, {})
+  monitoring                           = try(each.value.monitoring, var.defaults.monitoring, false)
+  network_interface                    = try(each.value.network_interface, var.defaults.network_interface, [])
+  placement_group                      = try(each.value.placement_group, var.defaults.placement_group, null)
+  private_ip                           = try(each.value.private_ip, var.defaults.private_ip, null)
+  root_block_device                    = try(each.value.root_block_device, var.defaults.root_block_device, [])
+  secondary_private_ips                = try(each.value.secondary_private_ips, var.defaults.secondary_private_ips, null)
+  source_dest_check                    = try(each.value.source_dest_check, var.defaults.source_dest_check, true)
+  subnet_id                            = try(each.value.subnet_id, var.defaults.subnet_id, null)
+  tags                                 = try(each.value.tags, var.defaults.tags, {})
+  tenancy                              = try(each.value.tenancy, var.defaults.tenancy, null)
+  user_data                            = try(each.value.user_data, var.defaults.user_data, null)
+  user_data_base64                     = try(each.value.user_data_base64, var.defaults.user_data_base64, null)
+  volume_tags                          = try(each.value.volume_tags, var.defaults.volume_tags, {})
+  enable_volume_tags                   = try(each.value.enable_volume_tags, var.defaults.enable_volume_tags, true)
+  vpc_security_group_ids               = try(each.value.vpc_security_group_ids, var.defaults.vpc_security_group_ids, null)
+  timeouts                             = try(each.value.timeouts, var.defaults.timeouts, {})
+  cpu_core_count                       = try(each.value.cpu_core_count, var.defaults.cpu_core_count, null)
+  cpu_threads_per_core                 = try(each.value.cpu_threads_per_core, var.defaults.cpu_threads_per_core, null)
+  create_spot_instance                 = try(each.value.create_spot_instance, var.defaults.create_spot_instance, false)
+  spot_price                           = try(each.value.spot_price, var.defaults.spot_price, null)
+  spot_wait_for_fulfillment            = try(each.value.spot_wait_for_fulfillment, var.defaults.spot_wait_for_fulfillment, null)
+  spot_type                            = try(each.value.spot_type, var.defaults.spot_type, null)
+  spot_launch_group                    = try(each.value.spot_launch_group, var.defaults.spot_launch_group, null)
+  spot_block_duration_minutes          = try(each.value.spot_block_duration_minutes, var.defaults.spot_block_duration_minutes, null)
+  spot_instance_interruption_behavior  = try(each.value.spot_instance_interruption_behavior, var.defaults.spot_instance_interruption_behavior, null)
+  spot_valid_until                     = try(each.value.spot_valid_until, var.defaults.spot_valid_until, null)
+  spot_valid_from                      = try(each.value.spot_valid_from, var.defaults.spot_valid_from, null)
+  putin_khuylo                         = try(each.value.putin_khuylo, var.defaults.putin_khuylo, true)
+}

wrappers/outputs.tf

@@ -0,0 +1,5 @@
+output "wrapper" {
+  description = "Map of outputs of a wrapper."
+  value       = module.wrapper
+  # sensitive = false  # No sensitive module output found
+}

wrappers/variables.tf

@@ -0,0 +1,11 @@
+variable "defaults" {
+  description = "Map of default values which will be used for each item."
+  type        = any
+  default     = {}
+}
+
+variable "items" {
+  description = "Maps of items to create a wrapper from. Values are passed through to the module."
+  type        = any
+  default     = {}
+}

wrappers/versions.tf

@@ -0,0 +1,3 @@
+terraform {
+  required_version = ">= 0.13.1"
+}