terraform-null-label

Overview

Terraform module designed to generate consistent label names and tags for resources. Use terraform-null-label to implement a strict naming convention.

Detected project types: Terraform, Make-based.

This repository was migrated from upstream source github.com/shafiqalibhai/terraform-null-label and is preserved here for archival, reference, or continued local development.

At a glance

• Default branch: master
• Visibility: public
• Size: 106 KB
• Created: 2026-04-27
• Last updated: 2026-04-27
• Stars / Forks / Open issues: 0 / 0 / 0
• License: Apache-2.0

Languages

Language	Bytes	Share
HCL	8,391 bytes	95.6%
Makefile	389 bytes	4.4%

Repository structure

• docs/
• examples/
• .gitignore (169 B)
• .travis.yml (241 B)
• LICENSE (11,351 B)
• main.tf (5,377 B)
• Makefile (389 B)
• outputs.tf (1,390 B)
• README.md (19,977 B)
• README.yaml (12,602 B)
• variables.tf (1,624 B)

Getting started

Clone the repository:

git clone https://forgejo.deployview.com/ssa/terraform-null-label.git
cd terraform-null-label

Installation

terraform init
terraform plan
terraform apply

make

Usage

Configure variables in a *.tfvars file or via -var flags, then run terraform plan to preview changes.

Original README

The content below is preserved from the previous README. Headings have been demoted so they don't compete with the new top-level sections.

terraform-null-label

Terraform module designed to generate consistent label names and tags for resources. Use terraform-null-label to implement a strict naming convention.

A label follows the following convention: {namespace}-{environment}-{stage}-{name}-{attributes}. The delimiter (e.g. -) is interchangeable. The label items are all optional. So if you perfer the term stage to environment you can exclude environment and the label id will look like {namespace}-{stage}-{name}-{attributes}. If attributes are excluded but stage and environment are included, id will look like {namespace}-{environment}-{stage}-{name}

It's recommended to use one terraform-null-label module for every unique resource of a given resource type. For example, if you have 10 instances, there should be 10 different labels. However, if you have multiple different kinds of resources (e.g. instances, security groups, file systems, and elastic ips), then they can all share the same label assuming they are logically related.

All Cloud Posse modules use this module to ensure resources can be instantiated multiple times within an account and without conflict.

NOTE: The null refers to the primary Terraform provider used in this module.

---

This project is part of our comprehensive "SweetOps" approach towards DevOps.

It's 100% Open Source and licensed under the APACHE2.

Usage

Simple Example

module "eg_prod_bastion_label" {
  source     = "git::https://github.com/cloudposse/terraform-null-label.git?ref=master"
  namespace  = "eg"
  stage      = "prod"
  name       = "bastion"
  attributes = ["public"]
  delimiter  = "-"
  tags       = "${map("BusinessUnit", "XYZ", "Snapshot", "true")}"
}

This will create an id with the value of eg-prod-bastion-public because when generating id, the default order is namespace, environment, stage, name, attributes (you can override it by using the label_order variable, see Advanced Example 3).

Now reference the label when creating an instance:

resource "aws_instance" "eg_prod_bastion_public" {
  instance_type = "t1.micro"
  tags          = "${module.eg_prod_bastion_label.tags}"
}

Or define a security group:

resource "aws_security_group" "eg_prod_bastion_public" {
  vpc_id = "${var.vpc_id}"
  name   = "${module.eg_prod_bastion_label.id}"
  tags   = "${module.eg_prod_bastion_label.tags}"
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

Advanced Example

Here is a more complex example with two instances using two different labels. Note how efficiently the tags are defined for both the instance and the security group.

module "eg_prod_bastion_abc_label" {
  source     = "git::https://github.com/cloudposse/terraform-null-label.git?ref=master"
  namespace  = "eg"
  stage      = "prod"
  name       = "bastion"
  attributes = ["abc"]
  delimiter  = "-"
  tags       = "${map("BusinessUnit", "ABC")}"
}

resource "aws_security_group" "eg_prod_bastion_abc" {
  name = "${module.eg_prod_bastion_abc_label.id}"
  tags = "${module.eg_prod_bastion_abc_label.tags}"
  ingress {
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

resource "aws_instance" "eg_prod_bastion_abc" {
   instance_type          = "t1.micro"
   tags                   = "${module.eg_prod_bastion_abc_label.tags}"
   vpc_security_group_ids = ["${aws_security_group.eg_prod_bastion_abc.id}"]
}

module "eg_prod_bastion_xyz_label" {
  source     = "git::https://github.com/cloudposse/terraform-null-label.git?ref=master"
  namespace  = "eg"
  stage      = "prod"
  name       = "bastion"
  attributes = ["xyz"]
  delimiter  = "-"
  tags       = "${map("BusinessUnit", "XYZ")}"
}

resource "aws_security_group" "eg_prod_bastion_xyz" {
  name = "${module.eg_prod_bastion_xyz_label.id}"
  tags = "${module.eg_prod_bastion_xyz_label.tags}"
  ingress {
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

resource "aws_instance" "eg_prod_bastion_xyz" {
   instance_type          = "t1.micro"
   tags                   = "${module.eg_prod_bastion_xyz_label.tags}"
   vpc_security_group_ids = ["${aws_security_group.eg_prod_bastion_xyz.id}"]
}

Advanced Example 2

Here is a more complex example with an autoscaling group that has a different tagging schema than other resources and requires its tags to be in this format, which this module can generate:

tags = [
    {
        key = Name,
        propagate_at_launch = 1,
        value = namespace-stage-name
    },
    {
        key = Namespace,
        propagate_at_launch = 1,
        value = namespace
    },
    {
        key = Stage,
        propagate_at_launch = 1,
        value = stage
    }
]

Autoscaling group using propagating tagging below (full example: autoscalinggroup)

################################
### terraform-null-label example #
################################
module "label" {
  source    = "../../"
  namespace = "cp"
  stage     = "prod"
  name      = "app"

  tags = {
    BusinessUnit = "Finance"
    ManagedBy    = "Terraform"
  }

  additional_tag_map = {
    propagate_at_launch = "true"
  }
}

#######################
### Launch template     #
#######################
resource "aws_launch_template" "default" {
  # terraform-null-label example used here: Set template name prefix
  name_prefix                           = "${module.label.id}-"
  image_id                              = "${data.aws_ami.amazon_linux.id}"
  instance_type                         = "t2.micro"
  instance_initiated_shutdown_behavior  = "terminate"

  vpc_security_group_ids                = ["${data.aws_security_group.default.id}"]

  monitoring {
    enabled                             = false
  }
  # terraform-null-label example used here: Set tags on volumes
  tag_specifications {
    resource_type                       = "volume"
    tags                                = "${module.label.tags}"
  }
}

######################
### Autoscaling group  #
######################
resource "aws_autoscaling_group" "default" {
  # terraform-null-label example used here: Set ASG name prefix
  name_prefix                           = "${module.label.id}-"
  vpc_zone_identifier                   = ["${data.aws_subnet_ids.all.ids}"]
  max_size                              = "1"
  min_size                              = "1"
  desired_capacity                      = "1"

  launch_template = {
    id                                  = "${aws_launch_template.default.id}"
    version                             = "$$Latest"
  }

  # terraform-null-label example used here: Set tags on ASG and EC2 Servers
  tags                                  = ["${module.label.tags_as_list_of_maps}"]
}

Advanced Example 3

See complete example

This example shows how you can pass the context output of one label module to the next label_module, allowing you to create one label that has the base set of values, and then creating every extra label as a derivative of that.

module "label1" {
  source      = "git::https://github.com/cloudposse/terraform-null-label.git?ref=master"
  namespace   = "CloudPosse"
  environment = "UAT"
  stage       = "build"
  name        = "Winston Churchroom"
  attributes  = ["fire", "water", "earth", "air"]
  delimiter   = "-"

  label_order = ["name", "environment", "stage", "attributes"]

  tags = {
    "City"        = "Dublin"
    "Environment" = "Private"
  }
}

module "label2" {
  source    = "git::https://github.com/cloudposse/terraform-null-label.git?ref=master"
  context   = "${module.label1.context}"
  name      = "Charlie"
  stage     = "test"
  delimiter = "+"

  tags = {
    "City"        = "London"
    "Environment" = "Public"
  }
}

module "label3" {
  source    = "git::https://github.com/cloudposse/terraform-null-label.git?ref=master"
  name      = "Starfish"
  stage     = "release"
  context   = "${module.label1.context}"
  delimiter = "."

  tags = {
    "Eat"    = "Carrot"
    "Animal" = "Rabbit"
  }
}

This creates label outputs like this:

label1 = {
  attributes = [fire water earth air]
  id = winstonchurchroom-uat-build-fire-water-earth-air
  name = winstonchurchroom
  namespace = cloudposse
  stage = build
}
label1_context = {
  attributes = [fire water earth air]
  delimiter = [-]
  environment = [uat]
  label_order = [name environment stage attributes]
  name = [winstonchurchroom]
  namespace = [cloudposse]
  stage = [build]
  tags_keys = [City Environment Name Namespace Stage]
  tags_values = [Dublin Private winstonchurchroom-uat-build-fire-water-earth-air cloudposse build]
}
label1_tags = {
  City = Dublin
  Environment = Private
  Name = winstonchurchroom-uat-build-fire-water-earth-air
  Namespace = cloudposse
  Stage = build
}
label2 = {
  attributes = [fire water earth air]
  id = charlie+uat+test+fire+water+earth+air
  name = charlie
  namespace = cloudposse
  stage = test
}
label2_context = {
  attributes = [fire water earth air]
  delimiter = [+]
  environment = [uat]
  label_order = [name environment stage attributes]
  name = [charlie]
  namespace = [cloudposse]
  stage = [test]
  tags_keys = [City Environment Name Namespace Stage]
  tags_values = [London Public charlie+uat+test+fire+water+earth+air cloudposse test]
}
label2_tags = {
  City = London
  Environment = Public
  Name = charlie+uat+test+fire+water+earth+air
  Namespace = cloudposse
  Stage = test
}
label3 = {
  attributes = [fire water earth air]
  id = starfish.uat.release.fire.water.earth.air
  name = starfish
  namespace = cloudposse
  stage = release
}
label3_context = {
  attributes = [fire water earth air]
  delimiter = [.]
  environment = [uat]
  label_order = [name environment stage attributes]
  name = [starfish]
  namespace = [cloudposse]
  stage = [release]
  tags_keys = [Animal City Eat Environment Name Namespace Stage]
  tags_values = [Rabbit Dublin Carrot uat starfish.uat.release.fire.water.earth.air cloudposse release]
}
label3_tags = {
  Animal = Rabbit
  City = Dublin
  Eat = Carrot
  Environment = uat
  Name = starfish.uat.release.fire.water.earth.air
  Namespace = cloudposse
  Stage = release
}

Makefile Targets

Available targets:

  help                                Help screen
  help/all                            Display help for all targets
  help/short                          This help short screen
  lint                                Lint terraform code

Inputs

Name	Description	Type	Default	Required
additional_tag_map	Additional tags for appending to each tag map	map	<map>	no
attributes	Additional attributes (e.g. 1)	list	<list>	no
context	Default context to use for passing state between label invocations	map	<map>	no
delimiter	Delimiter to be used between namespace, environment, stage, name and attributes	string	-	no
enabled	Set to false to prevent the module from creating any resources	string	true	no
environment	Environment, e.g. 'prod', 'staging', 'dev', 'pre-prod', 'UAT'	string	``	no
label_order	The naming order of the id output and Name tag	list	<list>	no
name	Solution name, e.g. 'app' or 'jenkins'	string	``	no
namespace	Namespace, which could be your organization name or abbreviation, e.g. 'eg' or 'cp'	string	``	no
stage	Stage, e.g. 'prod', 'staging', 'dev', OR 'source', 'build', 'test', 'deploy', 'release'	string	``	no
tags	Additional tags (e.g. map('BusinessUnit','XYZ')	map	<map>	no

Outputs

Name	Description
attributes	List of attributes
context	Context of this module to pass to other label modules
delimiter	Delimiter between namespace, environment, stage, name and attributes
environment	Normalized environment
id	Disambiguated ID
label_order	The naming order of the id output and Name tag
name	Normalized name
namespace	Normalized namespace
stage	Normalized stage
tags	Normalized Tag map
tags_as_list_of_maps	Additional tags as a list of maps, which can be used in several AWS resources

Related Projects

Check out these related projects.

• terraform-terraform-label - Terraform Module to define a consistent naming convention by (namespace, environment, stage, name, [attributes])

Help

Got a question?

File a GitHub issue, send us an email or join our Slack Community.

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Contributing

Bug Reports & Feature Requests

Please use the issue tracker to report any bugs or file feature requests.

Developing

If you are interested in being a contributor and want to get involved in developing this project or help out with our other projects, we would love to hear from you! Shoot us an email.

In general, PRs are welcome. We follow the typical "fork-and-pull" Git workflow.

1. Fork the repo on GitHub
2. Clone the project to your own machine
3. Commit changes to your own branch
4. Push your work back up to your fork
5. Submit a Pull Request so that we can review your changes

NOTE: Be sure to merge the latest changes from "upstream" before making a pull request!

Copyright

Copyright © 2017-2018 Cloud Posse, LLC

License

See LICENSE for full details.

Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

  https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.

Trademarks

All other trademarks referenced herein are the property of their respective owners.

About

This project is maintained and funded by Cloud Posse, LLC. Like it? Please let us know at hello@cloudposse.com

We're a DevOps Professional Services company based in Los Angeles, CA. We love Open Source Software!

We offer paid support on all of our projects.

Check out our other projects, apply for a job, or hire us to help with your cloud strategy and implementation.

Contributors

Erik Osterman	Andriy Knysh	Igor Rodionov	Sergey Vasilyev	Michael Pereira	Jamie Nelson	Vladimir	Daren Desjardins

Contributing

Contributions are welcome. The typical workflow is:

1. Open an issue describing the change you'd like to make.
2. Fork the repository (or create a feature branch if you have write access).
3. Commit your changes with clear, descriptive messages.
4. Open a pull request against the master branch.

Please follow the existing code style and include tests or reproduction steps where relevant.

License

This project is licensed under the Apache-2.0 license. See the LICENSE file for the full text.

Repository

• Browse: https://forgejo.deployview.com/ssa/terraform-null-label
• Clone (HTTPS): https://forgejo.deployview.com/ssa/terraform-null-label.git
• Clone (SSH): ssh://git@forgejo.deployview.com:30143/ssa/terraform-null-label.git
• Upstream / origin: github.com/shafiqalibhai/terraform-null-label

---

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