Updated Backup Policy documentation

website/docs/r/cloud_provider_snapshot_backup_policy.html.markdown

@@ -8,11 +8,14 @@ description: |-
 
 # mongodbatlas_cloud_provider_snapshot_backup_policy
 
-`mongodbatlas_cloud_provider_snapshot_backup_policy` provides a resource that enables you to view and modify the snapshot schedule and retention settings for an Atlas cluster with Cloud Backup enabled.  A default policy is created automatically when Cloud Backup is enabled for the cluster.  
+`mongodbatlas_cloud_provider_snapshot_backup_policy` provides a resource that enables you to view and modify the snapshot schedule and retention settings for an Atlas cluster with Cloud Backup enabled.  A default policy is created automatically when Cloud Backup is enabled for the cluster.
 
 -> **NOTE:** Groups and projects are synonymous terms. You may find `groupId` in the official documentation.
 
-## Example Usage
+# Examples - Modifying Polices
+When Cloud Backup is enabled for a cluster MongoDB Atlas automatically creates a default Cloud Backup schedule for the cluster with four policy items; hourly, daily, weekly, and monthly. Because of this default creation this provider automatically saves the Cloud Backup Snapshot Policy into the Terraform state when a cluster is created/modified to use Cloud Backup. If the default works well for you then you do not need to do anything other than create a cluster with Cloud Backup enabled and your Terraform state will have this information if you need it. However, if you want the policy to be different than the default we've provided some examples to help below.
+
+## Example Usage - Create a Cluster and Modify the 4 Default Policies Simultaneously
 
 ```hcl
 resource "mongodbatlas_cluster" "my_cluster" {
@@ -37,7 +40,8 @@ resource "mongodbatlas_cloud_provider_snapshot_backup_policy" "test" {
   reference_minute_of_hour = 45
   restore_window_days      = 4
 
-
+  //Keep all 4 default policies but modify the units and values
+  //Could also just reflect the policy defaults here for later management
   policies {
     id = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.id
 
@@ -48,20 +52,90 @@ resource "mongodbatlas_cloud_provider_snapshot_backup_policy" "test" {
       retention_unit     = "days"
       retention_value    = 1
     }
+
     policy_item {
       id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.1.id
       frequency_interval = 1
       frequency_type     = "daily"
       retention_unit     = "days"
       retention_value    = 2
     }
+
     policy_item {
       id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.2.id
       frequency_interval = 4
       frequency_type     = "weekly"
       retention_unit     = "weeks"
       retention_value    = 3
     }
+
+    policy_item {
+      id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.3.id
+      frequency_interval = 5
+      frequency_type     = "monthly"
+      retention_unit     = "months"
+      retention_value    = 4
+    }
+  }
+}
+```
+
+~> **IMPORTANT:**   `policies.#.policy_item.#.id` is obtained when the cluster is created. The example here shows the default order of the default policy when Cloud Backup is enabled (provider_backup_enabled is set to true).  The default policy is viewable in the Terraform State file.
+
+## Example Usage - Create a Cluster and Modify 3 Default Policies and Remove 1 Default Policy Simultaneously
+
+```hcl
+resource "mongodbatlas_cluster" "my_cluster" {
+  project_id   = "<PROJECT-ID>"
+  name         = "clusterTest"
+  disk_size_gb = 5
+
+  //Provider Settings "block"
+  provider_name               = "AWS"
+  provider_region_name        = "EU_CENTRAL_1"
+  provider_instance_size_name = "M10"
+  provider_backup_enabled     = true // must be enabled in order to use cloud_provider_snapshot_backup_policy resource
+  provider_disk_iops          = 100
+  provider_encrypt_ebs_volume = false
+}
+
+resource "mongodbatlas_cloud_provider_snapshot_backup_policy" "test" {
+  project_id   = mongodbatlas_cluster.my_cluster.project_id
+  cluster_name = mongodbatlas_cluster.my_cluster.name
+
+  reference_hour_of_day    = 3
+  reference_minute_of_hour = 45
+  restore_window_days      = 4
+
+
+  policies {
+    id = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.id
+
+    policy_item {
+      id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.0.id
+      frequency_interval = 1
+      frequency_type     = "hourly"
+      retention_unit     = "days"
+      retention_value    = 1
+    }
+
+    policy_item {
+      id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.1.id
+      frequency_interval = 1
+      frequency_type     = "daily"
+      retention_unit     = "days"
+      retention_value    = 2
+    }
+
+    # Item removed
+    # policy_item {
+    #   id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.2.id
+    #   frequency_interval = 4
+    #   frequency_type     = "weekly"
+    #   retention_unit     = "weeks"
+    #   retention_value    = 3
+    # }
+
     policy_item {
       id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.3.id
       frequency_interval = 5
@@ -73,6 +147,79 @@ resource "mongodbatlas_cloud_provider_snapshot_backup_policy" "test" {
 }
 ```
 
+-> **NOTE:** If you want the Cloud Backup Snapshot Policy to vary in the number of policies from the default when creating the cluster, perhaps you want to remove one policy item and modify the remaining three, simply follow this example here to remove a policy and modify three.
+
+~> **IMPORTANT:** If we decide to remove the 3rd item, as in our above example marked with `#`, we need to consider that once the cluster is modified or  `terraform refresh` is run the item `2` in the array will be replaced with content of the 4th item, so it could cause an inconsistency. This may be avoided by using hardcoded id values which will better handle this situation. (See below for an example of a hardcoded value)
+
+## Example Usage - Remove 3 Default Policies Items After the Cluster Has Already Been Created and Modify One Policy
+
+```hcl
+resource "mongodbatlas_cluster" "my_cluster" {
+  project_id   = "<PROJECT-ID>"
+  name         = "clusterTest"
+  disk_size_gb = 5
+
+  //Provider Settings "block"
+  provider_name               = "AWS"
+  provider_region_name        = "EU_CENTRAL_1"
+  provider_instance_size_name = "M10"
+  provider_backup_enabled     = true // must be enabled in order to use cloud_provider_snapshot_backup_policy resource
+  provider_disk_iops          = 100
+  provider_encrypt_ebs_volume = false
+}
+
+resource "mongodbatlas_cloud_provider_snapshot_backup_policy" "test" {
+  project_id   = mongodbatlas_cluster.my_cluster.project_id
+  cluster_name = mongodbatlas_cluster.my_cluster.name
+
+  reference_hour_of_day    = 3
+  reference_minute_of_hour = 45
+  restore_window_days      = 4
+
+
+  policies {
+    id = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.id
+
+    # Item removed
+    # policy_item {
+    #   id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.0.id
+    #   frequency_interval = 1
+    #   frequency_type     = "hourly"
+    #   retention_unit     = "days"
+    #   retention_value    = 1
+    # }
+
+    # Item removed
+    # policy_item {
+    #   id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.1.id
+    #   frequency_interval = 1
+    #   frequency_type     = "daily"
+    #   retention_unit     = "days"
+    #   retention_value    = 2
+    # }
+
+    # Item removed
+    # policy_item {
+    #   id                 = mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.2.id
+    #   frequency_interval = 4
+    #   frequency_type     = "weekly"
+    #   retention_unit     = "weeks"
+    #   retention_value    = 3
+    # }
+
+    policy_item {
+      id                 = 5f0747cad187d8609a72f546
+      frequency_interval = 5
+      frequency_type     = "monthly"
+      retention_unit     = "months"
+      retention_value    = 4
+    }
+  }
+}
+```
+
+-> **NOTE:** In this example we decided to remove the first 3 items so we can't use `mongodbatlas_cluster.my_cluster.snapshot_backup_policy.0.policies.0.policy_item.3.id` to retrieve the monthly id value of the cluster state due to once the cluster being modified or makes a `terraform refresh` will cause that the three items will remove from the state, so we will get an error due to the index 3 doesn't exists any more and our monthly policy item is moved to the first place of the array.  So we use `5f0747cad187d8609a72f546`, which is an example of an id MongoDB Atlas returns for the policy item we want to keep. Here it is hard coded because you need to either use the actual value from the Terraform state or look to map the policy item you want to keep to it's current placement in the state file array.
+
 ## Argument Reference
 
 * `project_id` - (Required) The unique identifier of the project for the Atlas cluster.
@@ -88,7 +235,7 @@ resource "mongodbatlas_cloud_provider_snapshot_backup_policy" "test" {
 
 #### Policy Item
 * `policies.#.policy_item` - (Required) Array of backup policy items.
-* `policies.#.policy_item.#.id` - (Required) Unique identifier of the backup policy item. `policies.#.policy_item.#.id` is a value obtained via the mongodbatlas_cluster resource. provider_backup_enabled of the mongodbatlas_cluster resource must be set to true. See the example above for how to refer to the mongodbatlas_cluster resource forpolicies.#.policy_item.#.id
+* `policies.#.policy_item.#.id` - (Required) Unique identifier of the backup policy item. `policies.#.policy_item.#.id` is a value obtained via the mongodbatlas_cluster resource. provider_backup_enabled of the mongodbatlas_cluster resource must be set to true. See the example above for how to refer to the mongodbatlas_cluster resource for policies.#.policy_item.#.id
 * `policies.#.policy_item.#.frequency_interval` - (Required) Desired frequency of the new backup policy item specified by frequencyType.
 * `policies.#.policy_item.#.frequency_type` - (Required) Frequency associated with the backup policy item. One of the following values: hourly, daily, weekly or monthly.
 * `policies.#.policy_item.#.retention_unit` - (Required) Scope of the backup policy item: days, weeks, or months.