Module: Network

This module provides a VPC with variable public and private subnets in it. The traffic of the public subnets is directly routed through the Internet Gateway and the resources in it are therefore exposed to the public internet. The traffic of the private subnets can be routed through a NAT Gateways.

Contents

• Requirements
• Inputs
• Outputs
• Example
• Contributing

Requirements

Name	Version
terraform	>= 1.0
aws	>= 5.20

Inputs

Name	Description	Type	Default	Required
identifier	Unique identifier to differentiate global resources.	string	n/a	yes
cidr	The IPv4 CIDR block of the VPC.	string	"10.0.0.0/16"	no
azs	A list of availability zone names in the region.	list(string)	[]	no
public_subnets	A list of CIDR blocks for the public subnets inside the VPC.	list(string)	[]	no
private_subnets	A list of CIDR blocks for the private subnets inside the VPC.	list(string)	[]	no
enable_hostnames	A flag to wether or not allow private DNS hostnames within the VPC.	bool	false	no
nat_gws	Number of NAT Gateways to create. NOTE: for every NAT Gateway a public subnet must exist, also it is recommended to not create more NAT Gateways than private subnets as the excessive NAT Gateways would have no use.	number	0	no
log_config	An object for the definition for a flow log of the VPC.	object	null	no
tags	A map of tags to add to all resources.	map(string)	{}	no

log_config

Name	Description	Type	Default	Required
traffic_type	The type of traffic to capture. Valid values: ACCEPT,REJECT, ALL.	string	n/a	yes
retention_in_days	Specifies the number of days the log events shall be retained. Valid values: 1, 3, 5, 7, 14, 30, 365 and 0 (never expire).	number	n/a	yes

Outputs

Name	Description
id	The ID of the VPC.
public_subnets	List of IDs of the public subnets.
private_subnets	List of IDs of the private subnets.
private_route_tables	List of IDs of the private route tables.
internet_gw	The ID of the Internet Gateway.
nat_gws	List of IDs of the NAT Gateways.
log_group_name	The name of the CloudWatch log group created for the VPC flow logs.
log_group_arn	The ARN of the CloudWatch log group created for the VPC flow logs.

Example

module "network" {
  source = "github.com/custom-terraform-aws-modules/network"

  identifier       = "example-network-dev"
  cidr             = "10.0.0.0/16"
  azs              = ["eu-central-1a", "eu-central-1b", "eu-central-1c"]
  public_subnets   = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
  private_subnets  = ["10.0.4.0/24", "10.0.5.0/24", "10.0.6.0/24"]
  enable_hostnames = true
  nat_gws          = 3

  log_config = {
    traffic_type      = "ALL"
    retention_in_days = 7
  }

  tags = {
    Project     = "example-project"
    Environment = "dev"
  }
}

Contributing

In order for a seamless CI workflow copy the pre-commit git hook from .github/hooks into your local .git/hooks. The hook formats the terraform code automatically before each commit.

cp ./.github/hooks/pre-commit ./.git/hooks/pre-commit