NCAS: Add WAF Setup (#3959)

terraform/environments/ncas/load_balancer.tf

@@ -156,3 +156,8 @@ resource "aws_lb_listener" "ncas_lb" {
     target_group_arn = aws_lb_target_group.ncas_target_group.arn
   }
 }
+
+resource "aws_wafv2_web_acl_association" "web_acl_association_my_lb" {
+  resource_arn = aws_lb.ncas_lb.arn
+  web_acl_arn  = aws_wafv2_web_acl.ncas_web_acl.arn
+}

terraform/environments/ncas/waf.tf

@@ -0,0 +1,36 @@
+resource "aws_wafv2_web_acl" "ncas_web_acl" {
+  name  = "ncas-web-acl"
+  scope = "REGIONAL"
+
+  default_action {
+    allow {}
+  }
+
+  rule {
+    name     = "common-rule-set"
+    priority = 1
+
+    override_action {
+      none {}
+    }
+
+    statement {
+      managed_rule_group_statement {
+        name        = "AWSManagedRulesCommonRuleSet"
+        vendor_name = "AWS"
+      }
+    }
+
+    visibility_config {
+      cloudwatch_metrics_enabled = true
+      metric_name                = "AWSManagedRulesCommonRuleSetMetrics"
+      sampled_requests_enabled   = true
+    }
+  }
+
+  visibility_config {
+    cloudwatch_metrics_enabled = true
+    metric_name                = "ncas-web-acl"
+    sampled_requests_enabled   = true
+  }
+}