terraform-null-label

Terraform module designed to generate consistent 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 prefer 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.

Releases of this module from 0.12.0 onward support HCL2 and only work with Terraform 0.12 or newer. Releases prior to this are compatible with earlier versions of terraform like Terraform 0.11.

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

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

We literally have hundreds of terraform modules that are Open Source and well-maintained. Check them out!

Usage

IMPORTANT: The master branch is used in source just as an example. In your code, do not pin to master because there may be breaking changes between releases. Instead pin to the release tag (e.g. ?ref=tags/x.y.z) of one of our latest releases.

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 = {
    "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 = {
    "BusinessUnit" = "XYZ",
    "Snapshot"     = "true"
  }
}

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 = {
    "BusinessUnit" = "XYZ",
    "Snapshot"     = "true"
  }
}

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",
  ]
  "delimiter" = "-"
  "id" = "winstonchurchroom-uat-build-fire-water-earth-air"
  "name" = "winstonchurchroom"
  "namespace" = "cloudposse"
  "stage" = "build"
}
label1_context = {
  "additional_tag_map" = {}
  "attributes" = [
    "fire",
    "water",
    "earth",
    "air",
  ]
  "delimiter" = "-"
  "enabled" = true
  "environment" = "uat"
  "label_order" = [
    "name",
    "environment",
    "stage",
    "attributes",
  ]
  "name" = "winstonchurchroom"
  "namespace" = "cloudposse"
  "regex_replace_chars" = "/[^a-zA-Z0-9-]/"
  "stage" = "build"
  "tags" = {
    "Attributes" = "fire-water-earth-air"
    "City" = "Dublin"
    "Environment" = "Private"
    "Name" = "winstonchurchroom"
    "Namespace" = "cloudposse"
    "Stage" = "build"
  }
}
label1_tags = {
  "Attributes" = "fire-water-earth-air"
  "City" = "Dublin"
  "Environment" = "Private"
  "Name" = "winstonchurchroom"
  "Namespace" = "cloudposse"
  "Stage" = "build"
}
label2 = {
  "attributes" = [
    "fire",
    "water",
    "earth",
    "air",
  ]
  "delimiter" = "+"
  "id" = "charlie+uat+test+firewaterearthair"
  "name" = "charlie"
  "namespace" = "cloudposse"
  "stage" = "test"
}
label2_context = {
  "additional_tag_map" = {}
  "attributes" = [
    "fire",
    "water",
    "earth",
    "air",
  ]
  "delimiter" = "+"
  "enabled" = true
  "environment" = "uat"
  "label_order" = [
    "name",
    "environment",
    "stage",
    "attributes",
  ]
  "name" = "charlie"
  "namespace" = "cloudposse"
  "regex_replace_chars" = "/[^a-zA-Z0-9-]/"
  "stage" = "test"
  "tags" = {
    "Attributes" = "firewaterearthair"
    "City" = "London"
    "Environment" = "Public"
    "Name" = "charlie"
    "Namespace" = "cloudposse"
    "Stage" = "test"
  }
}
label2_tags = {
  "Attributes" = "firewaterearthair"
  "City" = "London"
  "Environment" = "Public"
  "Name" = "charlie"
  "Namespace" = "cloudposse"
  "Stage" = "test"
}
label3 = {
  "attributes" = [
    "fire",
    "water",
    "earth",
    "air",
  ]
  "delimiter" = "."
  "id" = "starfish.uat.release.firewaterearthair"
  "name" = "starfish"
  "namespace" = "cloudposse"
  "stage" = "release"
}
label3_context = {
  "additional_tag_map" = {}
  "attributes" = [
    "fire",
    "water",
    "earth",
    "air",
  ]
  "delimiter" = "."
  "enabled" = true
  "environment" = "uat"
  "label_order" = [
    "name",
    "environment",
    "stage",
    "attributes",
  ]
  "name" = "starfish"
  "namespace" = "cloudposse"
  "regex_replace_chars" = "/[^a-zA-Z0-9-]/"
  "stage" = "release"
  "tags" = {
    "Animal" = "Rabbit"
    "Attributes" = "firewaterearthair"
    "City" = "Dublin"
    "Eat" = "Carrot"
    "Environment" = "uat"
    "Name" = "starfish"
    "Namespace" = "cloudposse"
    "Stage" = "release"
  }
}
label3_tags = {
  "Animal" = "Rabbit"
  "Attributes" = "firewaterearthair"
  "City" = "Dublin"
  "Eat" = "Carrot"
  "Environment" = "uat"
  "Name" = "starfish"
  "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

Requirements

Name	Version
terraform	>= 0.12.0, < 0.14.0

Providers

No provider.

Inputs

Name	Description	Type	Default	Required
additional_tag_map	Additional tags for appending to each tag map	`map(string)`	`{}`	no
attributes	Additional attributes (e.g. `1`)	`list(string)`	`[]`	no
context	Default context to use for passing state between label invocations	object({ namespace = string environment = string stage = string name = string enabled = bool delimiter = string attributes = list(string) label_order = list(string) tags = map(string) additional_tag_map = map(string) regex_replace_chars = string })	{ "additional_tag_map": {}, "attributes": [], "delimiter": "", "enabled": true, "environment": "", "label_order": [], "name": "", "namespace": "", "regex_replace_chars": "", "stage": "", "tags": {} }	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	`bool`	`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(string)`	`[]`	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
regex_replace_chars	Regex to replace chars with empty string in `namespace`, `environment`, `stage` and `name`. By default only hyphens, letters and digits are allowed, all other chars are removed	`string`	`"/[^a-zA-Z0-9-]/"`	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(string)`	`{}`	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

Share the Love

Like this project? Please give it a ★ on our GitHub! (it helps us a lot)

Are you using this project or any of our other projects? Consider leaving a testimonial. =)

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? We got answers.

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

DevOps Accelerator for Startups

We are a DevOps Accelerator. We'll help you build your cloud infrastructure from the ground up so you can own it. Then we'll show you how to operate it and stick around for as long as you need us.

Work directly with our team of DevOps experts via email, slack, and video conferencing.

We deliver 10x the value for a fraction of the cost of a full-time engineer. Our track record is not even funny. If you want things done right and you need it done FAST, then we're your best bet.

Reference Architecture. You'll get everything you need from the ground up built using 100% infrastructure as code.
Release Engineering. You'll have end-to-end CI/CD with unlimited staging environments.
Site Reliability Engineering. You'll have total visibility into your apps and microservices.
Security Baseline. You'll have built-in governance with accountability and audit logs for all changes.
GitOps. You'll be able to operate your infrastructure via Pull Requests.
Training. You'll receive hands-on training so your team can operate what we build.
Questions. You'll have a direct line of communication between our teams via a Shared Slack channel.
Troubleshooting. You'll get help to triage when things aren't working.
Code Reviews. You'll receive constructive feedback on Pull Requests.
Bug Fixes. We'll rapidly work with you to fix any bugs in our projects.

Slack Community

Join our Open Source Community on Slack. It's FREE for everyone! Our "SweetOps" community is where you get to talk with others who share a similar vision for how to rollout and manage infrastructure. This is the best place to talk shop, ask questions, solicit feedback, and work together as a community to build totally sweet infrastructure.

Discourse Forums

Participate in our Discourse Forums. Here you'll find answers to commonly asked questions. Most questions will be related to the enormous number of projects we support on our GitHub. Come here to collaborate on answers, find solutions, and get ideas about the products and services we value. It only takes a minute to get started! Just sign in with SSO using your GitHub account.

Newsletter

Sign up for our newsletter that covers everything on our technology radar. Receive updates on what we're up to on GitHub as well as awesome new projects we discover.

Office Hours

Join us every Wednesday via Zoom for our weekly "Lunch & Learn" sessions. It's FREE for everyone!

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.

Fork the repo on GitHub
Clone the project to your own machine
Commit changes to your own branch
Push your work back up to your fork
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

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 by leaving a testimonial!

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

We offer paid support on all of our projects.

Check out our other projects, follow us on twitter, 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	Maarten van der Hoef

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

README.md

README.md

terraform-null-label

Usage

Simple Example

Advanced Example

Advanced Example 2

Advanced Example 3

Makefile Targets

Requirements

Providers

Inputs

Outputs

Share the Love

Related Projects

Help

DevOps Accelerator for Startups

Slack Community

Discourse Forums

Newsletter

Office Hours

Contributing

Bug Reports & Feature Requests

Developing

Copyright

License

Trademarks

About

Contributors

Files

README.md

Latest commit

History

README.md

File metadata and controls

terraform-null-label

Usage

Simple Example

Advanced Example

Advanced Example 2

Advanced Example 3

Makefile Targets

Requirements

Providers

Inputs

Outputs

Share the Love

Related Projects

Help

DevOps Accelerator for Startups

Slack Community

Discourse Forums

Newsletter

Office Hours

Contributing

Bug Reports & Feature Requests

Developing

Copyright

License

Trademarks

About

Contributors