dynamic_backends

Global HTTP Load Balancer Terraform Module

Modular Global HTTP Load Balancer for GCE using forwarding rules.

This submodule allows for configuring dynamic backend outside Terraform. As such, any changes to the backends.groups variable after creation will be ignored.

Load Balancer Types

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

Compatibility

This module is meant for use with Terraform 1.3+ and tested using Terraform 1.3. If you find incompatibilities using Terraform >=1.3, 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 v4.5.0.

Version

Current version is 9.0. Upgrade guides:

• 2.X -> 3.0
• 3.X -> 4.0
• 6.X -> 7.0
• 7.X -> 8.0
• 8.X -> 9.0

Usage

module "gce-lb-http" {
  source            = "GoogleCloudPlatform/lb-http/google//modules/dynamic_backends"
  version           = "~> 9.0"

  project           = "my-project-id"
  name              = "group-http-lb"
  target_tags       = [module.mig1.target_tags, module.mig2.target_tags]
  backends = {
    default = {
      description                     = null
      port                            = var.service_port
      protocol                        = "HTTP"
      port_name                       = var.service_port_name
      timeout_sec                     = 10
      enable_cdn                      = false
      custom_request_headers          = null
      custom_response_headers         = null
      security_policy                 = null
      compression_mode                = null

      connection_draining_timeout_sec = null
      session_affinity                = null
      affinity_cookie_ttl_sec         = null

      health_check = {
        check_interval_sec  = null
        timeout_sec         = null
        healthy_threshold   = null
        unhealthy_threshold = null
        request_path        = "/"
        port                = var.service_port
        host                = null
        logging             = null
      }

      log_config = {
        enable = true
        sample_rate = 1.0
      }

      groups = [
        {
          # Each node pool instance group should be added to the backend.
          group                        = var.backend
          balancing_mode               = null
          capacity_scaler              = null
          description                  = null
          max_connections              = null
          max_connections_per_instance = null
          max_connections_per_endpoint = null
          max_rate                     = null
          max_rate_per_instance        = null
          max_rate_per_endpoint        = null
          max_utilization              = null
        },
      ]

      iap_config = {
        enable               = false
        oauth2_client_id     = null
        oauth2_client_secret = null
      }
    }
  }
}

Resources created

Figure 1. diagram of terraform resources

Inputs

Name	Description	Type	Default	Required
address	Existing IPv4 address to use (the actual IP address value)	string	null	no
backends	Map backend indices to list of backend maps.	map(object({ port = optional(number) project = optional(string) protocol = optional(string) port_name = optional(string) description = optional(string) enable_cdn = optional(bool) compression_mode = optional(string) security_policy = optional(string, null) edge_security_policy = optional(string, null) custom_request_headers = optional(list(string)) custom_response_headers = optional(list(string)) timeout_sec = optional(number) connection_draining_timeout_sec = optional(number) session_affinity = optional(string) affinity_cookie_ttl_sec = optional(number) health_check = object({ host = optional(string) request_path = optional(string) request = optional(string) response = optional(string) port = optional(number) port_name = optional(string) proxy_header = optional(string) port_specification = optional(string) protocol = optional(string) check_interval_sec = optional(number) timeout_sec = optional(number) healthy_threshold = optional(number) unhealthy_threshold = optional(number) logging = optional(bool) }) log_config = object({ enable = optional(bool) sample_rate = optional(number) }) groups = list(object({ group = string balancing_mode = optional(string) capacity_scaler = optional(number) description = optional(string) max_connections = optional(number) max_connections_per_instance = optional(number) max_connections_per_endpoint = optional(number) max_rate = optional(number) max_rate_per_instance = optional(number) max_rate_per_endpoint = optional(number) max_utilization = optional(number) })) iap_config = object({ enable = bool oauth2_client_id = optional(string) oauth2_client_secret = optional(string) }) cdn_policy = optional(object({ cache_mode = optional(string) signed_url_cache_max_age_sec = optional(string) default_ttl = optional(number) max_ttl = optional(number) client_ttl = optional(number) negative_caching = optional(bool) negative_caching_policy = optional(object({ code = optional(number) ttl = optional(number) })) serve_while_stale = optional(number) cache_key_policy = optional(object({ include_host = optional(bool) include_protocol = optional(bool) include_query_string = optional(bool) query_string_blacklist = optional(list(string)) query_string_whitelist = optional(list(string)) include_http_headers = optional(list(string)) include_named_cookies = optional(list(string)) })) })) }))	n/a	yes
certificate	Content of the SSL certificate. Required if ssl is true and ssl_certificates is empty.	string	null	no
certificate_map	Certificate Map ID in format projects/{project}/locations/global/certificateMaps/{name}. Identifies a certificate map associated with the given target proxy	string	null	no
create_address	Create a new global IPv4 address	bool	true	no
create_ipv6_address	Allocate a new IPv6 address. Conflicts with "ipv6_address" - if both specified, "create_ipv6_address" takes precedence.	bool	false	no
create_url_map	Set to false if url_map variable is provided.	bool	true	no
edge_security_policy	The resource URL for the edge security policy to associate with the backend service	string	null	no
enable_ipv6	Enable IPv6 address on the CDN load-balancer	bool	false	no
firewall_networks	Names of the networks to create firewall rules in	list(string)	[ "default" ]	no
firewall_projects	Names of the projects to create firewall rules in	list(string)	[ "default" ]	no
http_forward	Set to false to disable HTTP port 80 forward	bool	true	no
https_redirect	Set to true to enable https redirect on the lb.	bool	false	no
ipv6_address	An existing IPv6 address to use (the actual IP address value)	string	null	no
labels	The labels to attach to resources created by this module	map(string)	{}	no
load_balancing_scheme	Load balancing scheme type (EXTERNAL for classic external load balancer, EXTERNAL_MANAGED for Envoy-based load balancer, and INTERNAL_SELF_MANAGED for traffic director)	string	"EXTERNAL"	no
managed_ssl_certificate_domains	Create Google-managed SSL certificates for specified domains. Requires ssl to be set to true and use_ssl_certificates set to false.	list(string)	[]	no
name	Name for the forwarding rule and prefix for supporting resources	string	n/a	yes
network	Network for INTERNAL_SELF_MANAGED load balancing scheme	string	"default"	no
private_key	Content of the private SSL key. Required if ssl is true and ssl_certificates is empty.	string	null	no
project	The project to deploy to, if not set the default provider project is used.	string	n/a	yes
quic	Specifies the QUIC override policy for this resource. Set true to enable HTTP/3 and Google QUIC support, false to disable both. Defaults to null which enables support for HTTP/3 only.	bool	null	no
random_certificate_suffix	Bool to enable/disable random certificate name generation. Set and keep this to true if you need to change the SSL cert.	bool	false	no
security_policy	The resource URL for the security policy to associate with the backend service	string	null	no
ssl	Set to true to enable SSL support, requires variable ssl_certificates - a list of self_link certs	bool	false	no
ssl_certificates	SSL cert self_link list. Required if ssl is true and no private_key and certificate is provided.	list(string)	[]	no
ssl_policy	Selfink to SSL Policy	string	null	no
target_service_accounts	List of target service accounts for health check firewall rule. Exactly one of target_tags or target_service_accounts should be specified.	list(string)	[]	no
target_tags	List of target tags for health check firewall rule. Exactly one of target_tags or target_service_accounts should be specified.	list(string)	[]	no
url_map	The url_map resource to use. Default is to send all traffic to first backend.	string	null	no
use_ssl_certificates	If true, use the certificates provided by ssl_certificates, otherwise, create cert from private_key and certificate	bool	false	no

Outputs

Name	Description
backend_services	The backend service resources.
external_ip	The external IPv4 assigned to the global fowarding rule.
external_ipv6_address	The external IPv6 assigned to the global fowarding rule.
http_proxy	The HTTP proxy used by this module.
https_proxy	The HTTPS proxy used by this module.
ipv6_enabled	Whether IPv6 configuration is enabled on this load-balancer
url_map	The default URL map used by this module.

• google_compute_global_forwarding_rule.http: The global HTTP forwarding rule.
• google_compute_global_forwarding_rule.https: The global HTTPS forwarding rule created when ssl is true.
• google_compute_target_http_proxy.default: The HTTP proxy resource that binds the url map. Created when input ssl is false.
• google_compute_target_https_proxy.default: The HTTPS proxy resource that binds the url map. Created when input ssl is true.
• google_compute_ssl_certificate.default: The certificate resource created when input ssl is true and managed_ssl_certificate_domains not specified.
• google_compute_managed_ssl_certificate.default: The Google-managed certificate resource created when input ssl is true and managed_ssl_certificate_domains is specified.
• google_compute_url_map.default: The default URL map resource when input url_map is not provided.
• google_compute_backend_service.default.*: The backend services created for each of the backend_params elements.
• google_compute_health_check.default.*: Health check resources created for each of the (non global NEG) backend services.
• google_compute_firewall.default-hc: Firewall rule created for each of the backed services to allow health checks to the instance group.