feat/SA-251: notifications - conditional slack and teams resources (#35)

* feat: notifications - conditional slack and teams resources

* test: cannot default to null on accounts_id_to_name

* chore: and the README of course for change in variable default

README.md

@@ -39,7 +39,7 @@ module "account_baseline_alarms" {
 
 | Name | Source | Version |
 |------|--------|---------|
-| <a name="module_notifications"></a> [notifications](#module\_notifications) | appvia/notifications/aws | 1.0.2 |
+| <a name="module_notifications"></a> [notifications](#module\_notifications) | appvia/notifications/aws | 1.0.3 |
 
 ## Resources
 
@@ -87,7 +87,7 @@ module "account_baseline_alarms" {
 |------|-------------|------|---------|:--------:|
 | <a name="input_notification"></a> [notification](#input\_notification) | The configuration for how to send notifications. | <pre>object({<br>    email = optional(object({<br>      addresses = list(string)<br>    }), null)<br>    slack = optional(object({<br>      lambda_name = optional(string, "alarms-notifications")<br>      webhook_url = string<br>    }), null)<br>    teams = optional(object({<br>      webhook_url = string<br>    }), null)<br>  })</pre> | n/a | yes |
 | <a name="input_tags"></a> [tags](#input\_tags) | A map of tags to add to all resources | `map(string)` | n/a | yes |
-| <a name="input_accounts_id_to_name"></a> [accounts\_id\_to\_name](#input\_accounts\_id\_to\_name) | A mapping of account id and account name - used by notification lamdba to map an account ID to a human readable name | `map(string)` | `null` | no |
+| <a name="input_accounts_id_to_name"></a> [accounts\_id\_to\_name](#input\_accounts\_id\_to\_name) | A mapping of account id and account name - used by notification lamdba to map an account ID to a human readable name | `map(string)` | `{}` | no |
 | <a name="input_alarm_namespace"></a> [alarm\_namespace](#input\_alarm\_namespace) | The cloudwatch alarm namespace. | `string` | `"cis-benchmark"` | no |
 | <a name="input_cloudtrail_log_group_name"></a> [cloudtrail\_log\_group\_name](#input\_cloudtrail\_log\_group\_name) | The name of the CloudTrail log group to filter on. | `string` | `"aws-controltower/CloudTrailLogs"` | no |
 | <a name="input_create_sns_topic"></a> [create\_sns\_topic](#input\_create\_sns\_topic) | The boolean flag whether to create the SNS topic for alarms. | `bool` | `true` | no |

main.tf

@@ -2,7 +2,7 @@
 ## Provision the notifications  
 module "notifications" {
   source  = "appvia/notifications/aws"
-  version = "1.0.2"
+  version = "1.0.3"
 
   allowed_aws_services = ["cloudwatch.amazonaws.com"]
   create_sns_topic     = var.create_sns_topic

variables.tf

@@ -154,5 +154,5 @@ variable "tags" {
 variable "accounts_id_to_name" {
   description = "A mapping of account id and account name - used by notification lamdba to map an account ID to a human readable name"
   type        = map(string)
-  default     = null
-}
+  default     = {}
+}