terraform-aws-modules/terraform-aws-alb

The wrappers module implements a single module wrapper pattern. This allows you to manage multiple instances of the ALB/NLB module within a single configuration block. This is particularly useful in environments like Terragrunt where native Terraform for_each might not be feasible, or when you want to manage multiple resources without duplicating configuration files.

This wrapper does not add new functionality; it simply passes arguments through to the underlying root module. It uses two primary input maps:

1. defaults: A map of arguments applied to every instance created in the items map.
2. items: A map where each key represents a unique instance and the value is a map of arguments specific to that instance (which can override or supplement defaults).

The lb_trust_store wrapper is a pattern used to manage multiple instances of the modules/lb_trust_store module within a single configuration block. This is particularly useful in environments like Terragrunt where native Terraform for_each might not be feasible for managing multiple resource copies without duplicating configuration files.

This wrapper does not add new functionality; it simply provides a way to pass a map of items and a map of defaults to the underlying module.

The variable security_group_rules has been removed in v9.x. To align with underlying resource structures, you must now use two separate variables for ingress and egress:

• security_group_ingress_rules
• security_group_egress_rules

In v9.x, Listener Rules are migrated from indexed collections to map-based resources. You must use terraform state mv to move each rule from its v8.x index to its new v9.x key (which often follows a "listener_key/rule_key" pattern).

# Example: Migrating HTTP rules
terraform state mv 'module.alb.aws_lb_listener_rule.http_tcp_listener_rule[0]' 'module.alb.aws_lb_listener_rule.this["http-https-redirect/fixed-response"]'

# Example: Migrating HTTPS rules
terraform state mv 'module.alb.aws_lb_listener_rule.https_listener_rule[0]' 'module.alb.aws_lb_listener_rule.this["https/cognito"]'

Additional SSL certificates must be migrated from indexed collections to map-based resources in v9.x using terraform state mv.

# Example: Moving an additional certificate
terraform state mv 'module.alb.aws_lb_listener_certificate.https_listener[0]' 'module.alb.aws_lb_listener_certificate.this["https/0"]'

In v9.x, the method for creating listeners was simplified. Instead of multiple arguments, use a single listeners variable which accepts a map of listener definitions (using for_each).

Key changes:

• The target_group_index used in v8.x to associate listeners with target groups is replaced by target_group_key in v9.x.
• The target_group_key must match the key of the target group definition in your target_groups map.

# v9.x Listener Example
# listeners = {
#   listener_key = {
#     port     = 443
#     protocol = "HTTPS"
#     target_group_key = "tg1" # Must match key in target_groups map
#   }
# }

To use the wrapper directly in Terraform, call the module and provide the defaults and items arguments. Each entry in items can contain any argument supported by the root ALB/NLB module.

module "wrapper" {
  source = "terraform-aws-modules/alb/aws//wrappers"

  defaults = {
    create = true
    tags = {
      Terraform   = "true"
      Environment = "dev"
    }
  }

  items = {
    my-item = {
      # any argument supported by the root module
    }
    my-second-item = {
      # any argument supported by the root module
    }
  }
}

To use the wrapper with Terragrunt, set the source in your terraform block and define defaults and items within the inputs block. Use defaults for shared configuration and items to define the individual resource instances.

Note: You can use the tfr:/// source format or a direct Git source.

terraform {
  source = "tfr:///terraform-aws-modules/alb/aws//wrappers"
  # Alternative source:
  # source = "git::git@github.com:terraform-aws-modules/terraform-aws-alb.git//wrappers?ref=master"
}

inputs = {
  defaults = {
    create = true
    tags = {
      Terraform   = "true"
      Environment = "dev"
    }
  }

  items = {
    my-item = {
      # any argument supported by the root module
    }
    my-second-item = {
      # any argument supported by the root module
    }
  }
}

To use this wrapper with Terragrunt, define the source in the terraform block and provide defaults and items in the inputs block. The items map allows you to define multiple instances, where each key represents a unique identifier for an instance and the value is a map of arguments supported by the underlying module.

terraform {
  source = "tfr:///terraform-aws-modules/alb/aws//wrappers/lb_trust_store"
  # Alternative source:
  # source = "git::git@github.com:terraform-aws-modules/terraform-aws-alb.git//wrappers/lb_trust_store?ref=master"
}

inputs = {
  defaults = {
    create = true
    tags = {
      Terraform   = "true"
      Environment = "dev"
    }
  }

  items = {
    my-item = {
      # can be any argument supported by the module
    }
    my-second-item = {
      # can be any argument supported by the module
    }
  }
}