feat: manage default security group (#382)

README.md

@@ -316,6 +316,10 @@ It is possible to integrate this VPC module with [terraform-aws-transit-gateway
 | default\_network\_acl\_ingress | List of maps of ingress rules to set on the Default Network ACL | `list(map(string))` | <pre>[<br>  {<br>    "action": "allow",<br>    "cidr_block": "0.0.0.0/0",<br>    "from_port": 0,<br>    "protocol": "-1",<br>    "rule_no": 100,<br>    "to_port": 0<br>  },<br>  {<br>    "action": "allow",<br>    "from_port": 0,<br>    "ipv6_cidr_block": "::/0",<br>    "protocol": "-1",<br>    "rule_no": 101,<br>    "to_port": 0<br>  }<br>]</pre> | no |
 | default\_network\_acl\_name | Name to be used on the Default Network ACL | `string` | `""` | no |
 | default\_network\_acl\_tags | Additional tags for the Default Network ACL | `map(string)` | `{}` | no |
+| default\_security\_group\_egress | List of maps of egress rules to set on the default security group | `list(map(string))` | `null` | no |
+| default\_security\_group\_ingress | List of maps of ingress rules to set on the default security group | `list(map(string))` | `null` | no |
+| default\_security\_group\_name | Name to be used on the default security group | `string` | `"default"` | no |
+| default\_security\_group\_tags | Additional tags for the default security group | `map(string)` | `{}` | no |
 | default\_vpc\_enable\_classiclink | Should be true to enable ClassicLink in the Default VPC | `bool` | `false` | no |
 | default\_vpc\_enable\_dns\_hostnames | Should be true to enable DNS hostnames in the Default VPC | `bool` | `false` | no |
 | default\_vpc\_enable\_dns\_support | Should be true to enable DNS support in the Default VPC | `bool` | `true` | no |
@@ -496,6 +500,7 @@ It is possible to integrate this VPC module with [terraform-aws-transit-gateway
 | logs\_endpoint\_security\_group\_ids | The ID of one or more security groups to associate with the network interface for CloudWatch Logs endpoint | `list(string)` | `[]` | no |
 | logs\_endpoint\_subnet\_ids | The ID of one or more subnets in which to create a network interface for CloudWatch Logs endpoint. Only a single subnet within an AZ is supported. If omitted, private subnets will be used. | `list(string)` | `[]` | no |
 | manage\_default\_network\_acl | Should be true to adopt and manage Default Network ACL | `bool` | `false` | no |
+| manage\_default\_security\_group | Should be true to adopt and manage default security group | `bool` | `false` | no |
 | manage\_default\_vpc | Should be true to adopt and manage Default VPC | `bool` | `false` | no |
 | map\_public\_ip\_on\_launch | Should be false if you do not want to auto-assign public IP on launch | `bool` | `true` | no |
 | monitoring\_endpoint\_private\_dns\_enabled | Whether or not to associate a private hosted zone with the specified VPC for CloudWatch Monitoring endpoint | `bool` | `false` | no |

examples/complete-vpc/main.tf

@@ -106,6 +106,11 @@ module "vpc" {
   sqs_endpoint_private_dns_enabled = true
   sqs_endpoint_security_group_ids  = [data.aws_security_group.default.id]
 
+  # Default security group - ingress/egress rules cleared to deny all
+  manage_default_security_group  = true
+  default_security_group_ingress = [{}]
+  default_security_group_egress  = [{}]
+
   # VPC Flow Logs (Cloudwatch log group and IAM role will be created)
   enable_flow_log                      = true
   create_flow_log_cloudwatch_log_group = true

main.tf

@@ -54,6 +54,48 @@ resource "aws_vpc_ipv4_cidr_block_association" "this" {
   cidr_block = element(var.secondary_cidr_blocks, count.index)
 }
 
+resource "aws_default_security_group" "this" {
+  count = var.create_vpc && var.manage_default_security_group ? 1 : 0
+
+  vpc_id = aws_vpc.this[0].id
+
+  dynamic "ingress" {
+    for_each = var.default_security_group_ingress
+    content {
+      self             = lookup(ingress.value, "self", null)
+      cidr_blocks      = compact(split(",", lookup(ingress.value, "cidr_blocks", "")))
+      ipv6_cidr_blocks = compact(split(",", lookup(ingress.value, "ipv6_cidr_blocks", "")))
+      prefix_list_ids  = compact(split(",", lookup(ingress.value, "prefix_list_ids", "")))
+      description      = lookup(ingress.value, "description", null)
+      from_port        = lookup(ingress.value, "from_port", 0)
+      to_port          = lookup(ingress.value, "to_port", 0)
+      protocol         = lookup(ingress.value, "protocol", "-1")
+    }
+  }
+
+  dynamic "egress" {
+    for_each = var.default_security_group_egress
+    content {
+      self             = lookup(egress.value, "self", null)
+      cidr_blocks      = compact(split(",", lookup(egress.value, "cidr_blocks", "")))
+      ipv6_cidr_blocks = compact(split(",", lookup(egress.value, "ipv6_cidr_blocks", "")))
+      prefix_list_ids  = compact(split(",", lookup(egress.value, "prefix_list_ids", "")))
+      description      = lookup(egress.value, "description", null)
+      from_port        = lookup(egress.value, "from_port", 0)
+      to_port          = lookup(egress.value, "to_port", 0)
+      protocol         = lookup(egress.value, "protocol", "-1")
+    }
+  }
+
+  tags = merge(
+    {
+      "Name" = format("%s", var.default_security_group_name)
+    },
+    var.tags,
+    var.default_security_group_tags,
+  )
+}
+
 ###################
 # DHCP Options Set
 ###################
@@ -1105,4 +1147,3 @@ resource "aws_default_vpc" "this" {
     var.default_vpc_tags,
   )
 }
-

variables.tf

@@ -2259,12 +2259,42 @@ variable "elasticache_outbound_acl_rules" {
   ]
 }
 
+variable "manage_default_security_group" {
+  description = "Should be true to adopt and manage default security group"
+  type        = bool
+  default     = false
+}
+
+variable "default_security_group_name" {
+  description = "Name to be used on the default security group"
+  type        = string
+  default     = "default"
+}
+
+variable "default_security_group_ingress" {
+  description = "List of maps of ingress rules to set on the default security group"
+  type        = list(map(string))
+  default     = null
+}
+
 variable "enable_flow_log" {
   description = "Whether or not to enable VPC Flow Logs"
   type        = bool
   default     = false
 }
 
+variable "default_security_group_egress" {
+  description = "List of maps of egress rules to set on the default security group"
+  type        = list(map(string))
+  default     = null
+}
+
+variable "default_security_group_tags" {
+  description = "Additional tags for the default security group"
+  type        = map(string)
+  default     = {}
+}
+
 variable "create_flow_log_cloudwatch_log_group" {
   description = "Whether to create CloudWatch log group for VPC Flow Logs"
   type        = bool