feat(long_term_retention): add long term retention Terraform module

README.md

@@ -45,3 +45,4 @@ module "sql" {
 | database_id | Database resource ID |
 | database_name | Database name |
 | connection_string | ADO.NET connection string (sensitive) |
+Added LTR submodule scaffolding (modules/long_term_retention) with default 13-month retention.

main.tf

@@ -10,12 +10,32 @@ resource "azurerm_mssql_server" "this" {
   tags = var.tags
 }
 
+module "long_term_retention" {
+  source = "./modules/long_term_retention"
+
+  enabled           = var.long_term_retention_enabled
+  weekly_retention  = var.long_term_retention_weekly
+  monthly_retention = var.long_term_retention_monthly
+  yearly_retention  = var.long_term_retention_yearly
+  week_of_year      = var.long_term_retention_week_of_year
+}
+
 resource "azurerm_mssql_database" "this" {
   name        = var.database_name
   server_id   = azurerm_mssql_server.this.id
   sku_name    = var.sku_name
   max_size_gb = var.max_size_gb
 
+  dynamic "long_term_retention_policy" {
+    for_each = module.long_term_retention.enabled ? [module.long_term_retention.policy] : []
+    content {
+      weekly_retention  = long_term_retention_policy.value.weekly_retention
+      monthly_retention = long_term_retention_policy.value.monthly_retention
+      yearly_retention  = long_term_retention_policy.value.yearly_retention
+      week_of_year      = long_term_retention_policy.value.week_of_year
+    }
+  }
+
   tags = var.tags
 }
 

modules/long_term_retention/README.md

@@ -0,0 +1,57 @@
+# long_term_retention
+
+Centralises Long-Term Retention (LTR) policy settings for an Azure SQL
+Database, defaulting to **13 months** of monthly retention (`P13M`).
+
+With the azurerm provider build in use here, LTR is configured via the
+nested `long_term_retention_policy` block on the `azurerm_mssql_database`
+resource (there is no standalone LTR resource type). This module therefore
+exposes the policy values via outputs so they can be wired into the
+database resource.
+
+## Usage
+
+```hcl
+module "long_term_retention" {
+  source = "./modules/long_term_retention"
+
+  # Defaults to 13 months — override as needed.
+  monthly_retention = "P13M"
+}
+
+resource "azurerm_mssql_database" "this" {
+  # ... other arguments ...
+
+  dynamic "long_term_retention_policy" {
+    for_each = module.long_term_retention.enabled ? [module.long_term_retention.policy] : []
+    content {
+      weekly_retention  = long_term_retention_policy.value.weekly_retention
+      monthly_retention = long_term_retention_policy.value.monthly_retention
+      yearly_retention  = long_term_retention_policy.value.yearly_retention
+      week_of_year      = long_term_retention_policy.value.week_of_year
+    }
+  }
+}
+```
+
+## Inputs
+
+| Name | Description | Type | Default |
+|------|-------------|------|---------|
+| enabled | Whether to wire the LTR policy. | bool | true |
+| database_id | Optional, informational. | string | null |
+| weekly_retention | ISO 8601 weekly retention. | string | null |
+| monthly_retention | ISO 8601 monthly retention. | string | "P13M" |
+| yearly_retention | ISO 8601 yearly retention. | string | null |
+| week_of_year | Week (1-52) for yearly backup. | number | null |
+
+## Outputs
+
+| Name | Description |
+|------|-------------|
+| enabled | Whether the policy is enabled. |
+| policy | Object with all LTR block values, ready for the nested block. |
+| weekly_retention | Pass-through. |
+| monthly_retention | Pass-through. |
+| yearly_retention | Pass-through. |
+| week_of_year | Pass-through. |

modules/long_term_retention/main.tf

@@ -0,0 +1,31 @@
+# Long-Term Retention (LTR) configuration module.
+#
+# Note: With this azurerm provider build, LTR is configured via the
+# nested `long_term_retention_policy` block on the `azurerm_mssql_database`
+# resource (no standalone resource type is available).
+#
+# This module centralises and exposes the LTR settings (defaulting to 13
+# months of monthly retention) so that they can be wired into the database
+# resource via the `policy` output, e.g.:
+#
+#   resource "azurerm_mssql_database" "this" {
+#     ...
+#     dynamic "long_term_retention_policy" {
+#       for_each = var.enable_ltr ? [module.long_term_retention.policy] : []
+#       content {
+#         weekly_retention  = long_term_retention_policy.value.weekly_retention
+#         monthly_retention = long_term_retention_policy.value.monthly_retention
+#         yearly_retention  = long_term_retention_policy.value.yearly_retention
+#         week_of_year      = long_term_retention_policy.value.week_of_year
+#       }
+#     }
+#   }
+
+locals {
+  policy = {
+    weekly_retention  = var.weekly_retention
+    monthly_retention = var.monthly_retention
+    yearly_retention  = var.yearly_retention
+    week_of_year      = var.week_of_year
+  }
+}

modules/long_term_retention/outputs.tf

@@ -0,0 +1,29 @@
+output "enabled" {
+  description = "Whether the Long-Term Retention (LTR) policy is enabled."
+  value       = var.enabled
+}
+
+output "policy" {
+  description = "Long-Term Retention policy values to be applied to the long_term_retention_policy block of azurerm_mssql_database."
+  value       = local.policy
+}
+
+output "weekly_retention" {
+  description = "Weekly retention (ISO 8601 duration)."
+  value       = var.weekly_retention
+}
+
+output "monthly_retention" {
+  description = "Monthly retention (ISO 8601 duration). Defaults to P13M (13 months)."
+  value       = var.monthly_retention
+}
+
+output "yearly_retention" {
+  description = "Yearly retention (ISO 8601 duration)."
+  value       = var.yearly_retention
+}
+
+output "week_of_year" {
+  description = "Week of year used for yearly backup."
+  value       = var.week_of_year
+}

modules/long_term_retention/variables.tf

@@ -0,0 +1,35 @@
+variable "enabled" {
+  description = "Whether to enable the Long-Term Retention (LTR) policy. Exposed for consumers that conditionally wire the policy block."
+  type        = bool
+  default     = true
+}
+
+variable "database_id" {
+  description = "Optional ID of the Azure SQL Database the LTR policy applies to. Informational only — with this azurerm provider build, LTR is set via the nested long_term_retention_policy block on azurerm_mssql_database."
+  type        = string
+  default     = null
+}
+
+variable "weekly_retention" {
+  description = "Weekly backup retention period (ISO 8601 duration, e.g. P12W). Optional."
+  type        = string
+  default     = null
+}
+
+variable "monthly_retention" {
+  description = "Monthly backup retention period (ISO 8601 duration, e.g. P13M for 13 months). Defaults to 13 months."
+  type        = string
+  default     = "P13M"
+}
+
+variable "yearly_retention" {
+  description = "Yearly backup retention period (ISO 8601 duration, e.g. P5Y). Optional."
+  type        = string
+  default     = null
+}
+
+variable "week_of_year" {
+  description = "Week of year (1-52) for the yearly backup. Required by Azure if yearly_retention is set."
+  type        = number
+  default     = null
+}

modules/long_term_retention/versions.tf

@@ -0,0 +1,10 @@
+terraform {
+  required_version = ">= 1.3.0"
+
+  required_providers {
+    azurerm = {
+      source  = "hashicorp/azurerm"
+      version = ">= 3.0.0, < 5.0.0"
+    }
+  }
+}

variables.tf

@@ -49,3 +49,33 @@ variable "tags" {
   type        = map(string)
   default     = {}
 }
+
+variable "long_term_retention_enabled" {
+  description = "Whether to enable the Long-Term Retention (LTR) policy on the SQL database."
+  type        = bool
+  default     = true
+}
+
+variable "long_term_retention_weekly" {
+  description = "Weekly LTR retention (ISO 8601 duration, e.g. P12W). Optional."
+  type        = string
+  default     = null
+}
+
+variable "long_term_retention_monthly" {
+  description = "Monthly LTR retention (ISO 8601 duration). Defaults to P13M (13 months) per requirement."
+  type        = string
+  default     = "P13M"
+}
+
+variable "long_term_retention_yearly" {
+  description = "Yearly LTR retention (ISO 8601 duration, e.g. P5Y). Optional."
+  type        = string
+  default     = null
+}
+
+variable "long_term_retention_week_of_year" {
+  description = "Week of year (1-52) for the yearly LTR backup. Required by Azure if long_term_retention_yearly is set."
+  type        = number
+  default     = null
+}