TagsAddingAspect example produces Self-referential block

[danielBreitlauch]

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cdktf & Language Versions

cdktf: 0.11.2
terraform: 1.2.3
typescript

Affected Resource(s)

aws_ssm_parameter but any resource with non empty tags.

Debug Output

The Gist contains the generated terraform json and the error.
Gist

Expected Behavior

Tags should have been read from the resource, merged and readied to the resource.

Actual Behavior

Terraform considers this a self-referential block and aborts.

Steps to Reproduce

1. Take the example from https://www.terraform.io/cdktf/concepts/aspects
2. add a ssm parameter

[DanielMSchmidt]

const currentTags = node.tags || {}; should be const currentTags = node.tagsInput || {};, we need to update the docs

[danielBreitlauch]

Makes sense. Thx.
And keep up the good work. Cdktf is awesome.

[danielBreitlauch]

I tested it and see another problem.

new SecurityGroup(this, "autoscaling-sg", { [...], tags: { test: "ing"} })

In this case node.tagsInput is empty but node.tags contains just the dict.
Any ideas?

[DanielMSchmidt]

I think since we are not dealing with tokens anymore you should be able to do node.tags = { ...this.tagsToAdd, ...node.tagsInput,}

[danielBreitlauch]

This overwrites the existing tags added elsewhere. Like { test: "ing"} above.

[galaabattur]

I have tried with both approaches but still getting error.
for the
const currentTags = node.tags || {}; node.tags = { ...this.tagsToAdd, ...currentTags };
error says
Error: Cannot add elements to map token, got: {"test1":"test-adding-tags","&{TfToken[TOKEN.3]}":"String Map Token Value"}. You tried to add a value to a referenced map, instead use Fn.merge([yourReferencedMap, { your: 'value' }]). which makes us to use Fn.merge() and Fn.tomap()
However using Fn.merge() and Fn.tomap() leads us to Self-referential block error, which is circular dependency.
Do we have other approaches to handle this?

[ansgarm]

Hi @galaabattur, have you seen the commit from @DanielMSchmidt (back-linked above)?
It updates the docs to solve that issue by using the tagsInput value for the current tags:

// We need to take the input value to not create a circular reference
const currentTags = node.tagsInput || {};
node.tags = { ...this.tagsToAdd, ...currentTags };

Does that solve it for you as well?

[galaabattur]

Hi @ansgarm thank you for the response. I have tried it and have following question. In this case, where would tagsInput be defined, is it in TaggableConstruct type? otherwise typescript will complain that cannot find the property in the TaggableConstruct type, or is it in the cdktf types?
I think the idea is just to have the current tags and merge with new tags and override with current ones. Thank you

[ansgarm]

Hi @galaabattur,
you're right, we might need to add it to the TaggableConstruct type definition in our Aspects example. It is originally defined in the generated bindings (e.g. here for an S3 Bucket).
The input* attributes can be used to reference whatever was passed to the construct (e.g. here the internal _tags attribute is assigned when assigning something to node.tags = .... So this will take the current tags and merge them with the next ones – if you would use node.tags instead of node.tagsInput it would return a reference instead that will work when Terraform is invoked for example (but you can't change that value in your CDKTF program, that's why that caused an error).

Going to re-open this to fix that the Aspects example does not fail with a type error due to tagsInput now being used.

[github-actions]

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