A metadata module for AWS resources management

This module try to manage the follow items easy, unified and flexible with DRY

Resource meta data with same format
Tags, auto generated tags
Auto generated resource Name and Id if it missed(for some AWS resources)

Input of context

context_values

A map name context to initialize the module, those metadata fields are valid,

org - Org or company name
dept - Department name
team - Team name
app - Application name
service - Service name
component - Component Name
env - Environment Name
stage - Stage Name
alt_env - Alternative env name
region - Region Name
alt_region - Alternative Region name, e.g. uw2 as short one

To avoid too long label and id name generated, please use shorter name or abbr for this module. Almost all the attributes can be override.

label_attributes and label_delimiter

label.attributes, a attributes list, is used to build the label(name), the order of the list items is applied to the label. The label_attributes items MUST be present in the context map,

Default

label.atrributes = ["team", "service", "component", "env", "region"]

The default label will be team-service-component-env-region as the default label.delimiter is "-".

context_values = {
    team = "myTeam"
    service = "myService"
    component = "myServiceCom"
    env = "dev"
    region = "us-west-2"
}

Then the generated label will be "myTeam-myService-myServiceCom-dev-us-west-2"; label.delimiter can be override too. The generated id will be the label appending random id(8 characters).

tag_attributes and tag_prefix, additional_tags

The attributes in the context to be tagged and prefix for tag Name

In the above sample input context, if the tag_attributes as default(["team", "service", "component", "env"]), then the tags list will be(tag_prefix is iac: as default)

iac:TEAM = myteam
iac:SERVICE = myservice
iac:COMPONENT = myservicecom
iac:ENV = dev

if additional_tags is present, that map will be appended directly

The common situation is that in the context.tf, set the additional_tags = var.tags, then at the AWS Resource tags attribute, assign it as module.context.tags.

Output of the module

label and name, now they are both set to auto-generated label mentioned above
id - The label value appending an random id as the context.id, used for unique case
tags - The auto generated tags map
env - Expose the env in context_values if present or dev
region - Expose the region in context_values if present or us-west-2

Sample of context.tf file in Terraform module

Please notice the source location might be different according to the module location. It can be,

Relative path in the module is in the sampe repos
GitHub URL

module "context" {
  source = a3linux/context/null

  context_values = var.context
  additional_tags = try(var.tags, {})
}

variable "context" {
  type = map(any)
  description = "Description of context"
  default = {
    env = "dev"
    region = "us-west-2"
    team = "myTeam"
    service = "myService"
    component = "myServiceCom"
  }
}

Placeholder of label and id in additional_tags

Only CONTEXT:label and CONTEXT:id are supported as placeholder value for additional_tags.

For example,

...
additional_tags = {
    "my:custom" = "CONTEXT:label"
}
...

The my:custom will have the tag value as the label generated by context module. This provide another way to re-use the module attribute for tag.

The context variable can be provided through terragrunt or other variables for flexible and customization.

a3linux/terraform-null-context