Regional TCP Load Balancer Terraform Module

This is a collection of modules for external TCP/UDP load balancers. The root module is an implementation of passthrough regional TCP Load Balancer for GCE using target pool and forwarding rule. A regional proxy based external load balancer is implemented as a submodlue[modules/regional_proxy_lb/].

Load Balancer Types

• TCP load balancer
• HTTP/S load balancer
• Internal load balancer

Compatibility

This module is meant for use with Terraform 0.13+ and tested using Terraform 1.0+. If you find incompatibilities using Terraform >=0.13, please open an issue. If you haven't upgraded and need a Terraform 0.12.x-compatible version of this module, the last released version intended for Terraform 0.12.x is v2.3.0.

Usage

Basic usage is as follows:

module "load_balancer" {
  source       = "GoogleCloudPlatform/lb/google"
  version      = "~> 2.0.0"
  region       = var.region
  name         = "load-balancer"
  service_port = 80
  target_tags  = ["allow-lb-service"]
  network      = var.network
}

module "managed_instance_group" {
  source            = "terraform-google-modules/vm/google//modules/mig"
  version           = "~> 1.0.0"
  region            = var.region
  target_size       = 2
  hostname          = "mig-simple"
  instance_template = module.instance_template.self_link
  target_pools      = [module.load_balancer.target_pool]
  named_ports = [{
    name = "http"
    port = 80
  }]
}

Full functional examples are located in the examples directory.

Resources Created

Figure 1. Diagram of Terraform resources created by module (in green).

• google_compute_forwarding_rule.default: TCP Forwarding rule to the service port on the instances.
• google_compute_target_pool.default: The target pool created for the instance group.
• google_compute_http_health_check.default: The health check for the instance group targeted at the service port.
• google_compute_firewall.default-lb-fw: Firewall that allows traffic from anywhere to instances service port.

Inputs

Name	Description	Type	Default	Required
allowed_ips	The IP address ranges which can access the load balancer.	list(string)	[ "0.0.0.0/0" ]	no
disable_health_check	Disables the health check on the target pool.	bool	false	no
firewall_project	Name of the project to create the firewall rule in. Useful for shared VPC. Default is var.project.	string	""	no
health_check	Health check to determine whether instances are responsive and able to do work	object({ check_interval_sec = number healthy_threshold = number timeout_sec = number unhealthy_threshold = number port = number request_path = string host = string })	{ "check_interval_sec": null, "healthy_threshold": null, "host": null, "port": null, "request_path": null, "timeout_sec": null, "unhealthy_threshold": null }	no
ip_address	IP address of the external load balancer, if empty one will be assigned.	string	null	no
ip_protocol	The IP protocol for the frontend forwarding rule and firewall rule. TCP, UDP, ESP, AH, SCTP or ICMP.	string	"TCP"	no
labels	The labels to attach to resources created by this module.	map(string)	{}	no
name	Name for the forwarding rule and prefix for supporting resources.	string	n/a	yes
network	Name of the network to create resources in.	string	"default"	no
project	The project to deploy to, if not set the default provider project is used.	string	""	no
region	Region used for GCP resources.	string	n/a	yes
service_port	TCP port your service is listening on.	number	n/a	yes
session_affinity	How to distribute load. Options are NONE, CLIENT_IP and CLIENT_IP_PROTO	string	"NONE"	no
target_service_accounts	List of target service accounts to allow traffic using firewall rule.	list(string)	null	no
target_tags	List of target tags to allow traffic using firewall rule.	list(string)	null	no

Outputs

Name	Description
external_ip	The external ip address of the forwarding rule.
target_pool	The self_link to the target pool resource created.

health_check variable

The health_check variable values are passed on to the google_compute_http_health_check resource. Setting values to null will use google_compute_http_health_check defaults. It takes the following parameters:

Name	Description	Default	Requirement
check_interval_sec	How often (in seconds) to send a health check	5	no
healthy_threshold	A so-far unhealthy instance will be marked healthy after this many consecutive successes	2	no
host	The value of the host header in the HTTP health check request	""	no
port	The TCP port number for the HTTP health check request	80	no
request_path	The request path of the HTTP health check request	/	no
timeout_sec	How long (in seconds) to wait before claiming failure	5	no
unhealthy_threshold	A so-far healthy instance will be marked unhealthy after this many consecutive failures	2	no