feat: add secondary record and failover policy

Author: Premdeep Saini

README.md

@@ -39,6 +39,11 @@ module "app_ingress" {
   target_group_healthcheck_protocol            = "HTTP"
   target_group_healthcheck_interval            = 30
   target_group_healthcheck_timeout             = 5
+  enable_failover_policy                       = true
+  primary_record_healthcheck_id                = "primary_healthcheck_id"
+  secondary_record_alias_name                  = "secondary_alias_name"
+  secondary_record_zone_id                     = "secondary_zone_id"
+  secondary_record_healthcheck_id              = "secondary_healthcheck_id" 
 }
 ```
 
@@ -83,6 +88,7 @@ No modules.
 | [aws_lb_listener_rule.app](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/lb_listener_rule) | resource |
 | [aws_lb_target_group.app](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/lb_target_group) | resource |
 | [aws_route53_record.alb_record](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/route53_record) | resource |
+| [aws_route53_record.secondary_alb_record](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/route53_record) | resource |
 | [aws_route53_record.app_validation](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/route53_record) | resource |
 | [aws_s3_bucket.alb_access_logs](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/s3_bucket) | resource |
 | [aws_s3_bucket_acl.alb_access_logs_private](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/s3_bucket_acl) | resource |
@@ -120,6 +126,11 @@ No modules.
 | target_group_healthcheck_port                    	| Port to use to connect with the target. Valid values are any valid port or "traffic-port". Defaults to "traffic-port".                   	| `string`       	| "traffic-port" 	| no       	|
 | target_group_healthcheck_protocol                	| Protocol to use to connect with the target. Defaults to "HTTP".                                                                          	| `string`       	| "HTTP"         	| no       	|
 | target_group_healthcheck_timeout                 	| Amount of time, in seconds, during which no response means a failed health check. Defaults to 5.                                         	| `number`       	| 5              	| no       	|
+| enable_failover_policy                            | Should enable/disable Failover policy for the subdomain record                                                                            | `bool`            | `false`           | no        |
+| primary_record_healthcheck_id                     | For Failover Routing policy only. Healthcheck Id of primary record.                                                                       | `string`          | `null`            | no        |
+| secondary_record_alias_name                       | For Failoverrouting policy only. Alias name for secondary record.                                                                         | `string`          | `null`            | no        |
+| secondary_record_healthcheck_id                   | For Failover Routing policy only. Healthcheck Id of secondary record.                                                                     | `string`          | `null`            | no        |
+| secondary_record_zone_id                          | For Failoverrouting policy only. Zone Id for secondary record.                                                                            | `string`          | `null`            | no        |
 
 ### Outputs
 

route53.tf

@@ -11,6 +11,31 @@ resource "aws_route53_record" "alb_record" {
     name                   = aws_lb.alb.dns_name
     zone_id                = aws_lb.alb.zone_id
   }
+  dynamic "failover_routing_policy" {
+    for_each = var.enable_failover_policy ? { value : "dummy_value" } : {}
+    content {
+      type = "PRIMARY"
+    }
+  }
+  health_check_id = var.enable_failover_policy ? var.primary_record_healthcheck_id : null
+  set_identifier  = var.enable_failover_policy ? "primary_${var.app_subdomain_name}" : null
+}
+
+resource "aws_route53_record" "secondary_alb_record" {
+  count   = var.enable_failover_policy ? 1 : 0
+  name    = var.app_subdomain_name
+  type    = "A"
+  zone_id = data.aws_route53_zone.zone.zone_id
+  alias {
+    evaluate_target_health = false
+    name                   = var.secondary_record_alias_name
+    zone_id                = var.secondary_record_zone_id
+  }
+  health_check_id = var.secondary_record_healthcheck_id
+  set_identifier  = "secondary_${var.app_subdomain_name}"
+  failover_routing_policy {
+    type = "SECONDARY"
+  }
 }
 
 resource "aws_route53_record" "app_validation" {

variables.tf

@@ -113,3 +113,33 @@ variable "target_group_deregistration_delay" {
   description = "Amount of time, in seconds, for Elastic Load Balancing to wait before changing the state of a deregistering target from draining to unused"
   default     = 300
 }
+
+variable "enable_failover_policy" {
+  type        = bool
+  description = "Should enable/disable Failover policy for the subdomain record"
+  default     = false
+}
+
+variable "primary_record_healthcheck_id" {
+  type        = string
+  description = "For Failover Routing policy only. Healthcheck Id of primary record."
+  default     = null
+}
+
+variable "secondary_record_alias_name" {
+  type        = string
+  description = "For Failoverrouting policy only. Alias name for secondary record."
+  default     = null
+}
+
+variable "secondary_record_zone_id" {
+  type        = string
+  description = "For Failoverrouting policy only. Zone Id for secondary record."
+  default     = null
+}
+
+variable "secondary_record_healthcheck_id" {
+  type        = string
+  description = "For Failover Routing policy only. Healthcheck Id of secondary record."
+  default     = null
+}