[Feature] slim down to null_data_source and exclude_label_tags

[dennybaa]

Motivation is to provide an abstract base for other null_labels.

/* some tf file */
module "project" {
  ...
  user_tags_only = true
  tags = {
    ManagedBy = "terraform"
    Foo = "bar"
  }
}

/* using an abstract base to initialize with inherited tags */
module "kops" {
   name = "kops"
   namespace = "${module.project.namespace}"
   stage = "${module.project.stage}"
   tags = "${module.project.tags}
}

[osterman]

I think this is a good suggestion. Can we think of another name for user_tags_only?

e.g. override_tags

[osterman]

@Jamie-BitFlight what do you think about this enhancement?

Also, I think there's some danger here if the Name tag is not overriden as then there's signficicant risk of collisions.

[osterman]

Also, what about doing something different: adding support for a context output which is a map of the current label state. Then we support an optional context variable. This way we could pass state between modules relatively easily.

/* some tf file */
module "project" {
  ...
  user_tags_only = true
  tags = {
    ManagedBy = "terraform"
    Foo = "bar"
  }
}

/* using an abstract base to initialize with inherited tags */
module "kops" {
   name = "kops"
   context = "${module.project.context}"
}

[dennybaa]

Also, you've mentioned tags as normalized . In fact there's no normalization... keys are untouched and basically everything is outputted exactly as it was passed via variable plus Name/Stage/Namespace...

[osterman]

These are the normalized fields:
https://github.com/stackfeed/terraform-null-label/blob/c0d03bea486fc175d6e555737bd98acb4235fb29/main.tf#L3-L7

They are lowercased. Attributes are joined with a delimiter.

[dennybaa]

yup, right i've missed that

[dennybaa]

@osterman Hey, I've actually fixed the commit. Not sure that override_tags is a good and self-explanatory variable name. This time I come out with a name exclude_label_tags which are Name/Namespace/Stage, it sounds good for me...

[osterman]

What you do you think about renaming exclude_label_tags to generate_tags or auto_generate_tags? So if generate_tags is false, we do not add the Name, Stage, and Namespace tags.

[osterman]

@dennybaa checkout this alternative: #25

[aknysh]

Addressed in #36