Terragrunt: Unapplied dependency outputs error

[clarklai]

Terraform v0.20.2

I'm following along with the documentation (https://github.com/gruntwork-io/terragrunt#unapplied-dependency-and-mock-outputs), but seem to keep running into the error:

Unsupported attribute; This object does not have an attribute named "platform".

I have a pretty straightforward configuration, using mock_outputs, mock_outputs_allowed_terraform_commands, and skip_outputs:

# hosting/terragrunt.hcl

terraform {
  source = "${get_terragrunt_dir()}/../../../core/hosting/module"
}

dependency "platform" {
  config_path = "../platform"

  mock_outputs = {
    api_gateway_name = "test_api_gateway_name"
  }

  mock_outputs_allowed_terraform_commands = ["validate", "plan"]
  skip_outputs = true
}

inputs = {
  api_gateway_name = dependency.platform.outputs.platform
}

Project structure:

root
├── hosting
│   └── terragrunt.hcl
├── platform
│   └── terragrunt.hcl
└── terragrunt.hcl

Is there something I'm missing?

Thanks

[yorinasub17]

Hi can you share the full log, starting with the command you are running? That context helps a lot for debugging this. Thanks!

[yorinasub17]

Oh wait, taking a deeper look at the config, I think I spot the problem:

In the inputs, you are referencing:

dependency.platform.outputs.platform

but in your definition of mock_outputs, you don't have a key for platform. Should this actually be: dependency.platform.outputs.api_gateway_name?

[clarklai]

Thanks for the response @yorinasub17. You're absolutely right, I misread the documentation - I read it as mock_outputs keys are to match the keys of the inputs block. Thanks again for catching that.

[clarklai]

@yorinasub17 It looks like even after changing the key, the issue persists:

Unsupported attribute; This object does not have an attribute named "outputs"

Here's the configuration:

# hosting/terragrunt.hcl

terraform {
  source = "${get_terragrunt_dir()}/../../../core/hosting/module"
}

dependency "platform" {
  config_path = "../platform"

  mock_outputs = {
    api_gateway_name = "test_api_gateway_name"
  }

  mock_outputs_allowed_terraform_commands = ["validate", "plan"]
  skip_outputs = true
}

inputs = {
  api_gateway_name = dependency.platform.outputs.api_gateway_name
}

[barryib]

@clarklai what Terragrunt command are you using ? Can you please share the full log as @yorinasub17 suggested ?

[clarklai]

I resolved the issue. It was because I had skip_outputs = true in the dependency definition.

[yorinasub17]

That sounds like a bug, since we introduced the behavior to return the mock_outputs when skip_outputs = true in v0.19.29.

Would you be ok with sharing the logs still so we can investigate this further and make sure there isn't an issue in terragrunt itself?

[barryib]

From what I understood from the code, you get this error only when these 2 are true :

• skip_outputs is true => you don't want to pull in states. This can make sense only with the validate
• mock_outputs_allowed_terraform_commands doesn't match the Terraform command you're using

In short, if you don't want to read states and don't provide allowed commands, you can't have dependency outputs.

@yorinasub17 @clarklai can we re-open this issue until we make this clair ?

[clarklai]

I've made some updates to the configuration since my last post, however the issue returns when adding back skip_outputs to the configuration.

skip_outputs.log

[barryib]

[terragrunt] 2019/10/16 20:41:25 configstack.MultiError Encountered the following errors:
Cannot process module Module /Users/clark/example/deploy/dev/hosting (excluded: false, dependencies: [/Users/clark/example/deploy/dev/platform, /Users/clark/example/deploy/dev/email]) because one of its dependencies, Module /Users/clark/example/framewo
rk/deploy/dev/email (excluded: false, dependencies: [/Users/clark/example/deploy/dev/platform]), finished with an error: /Users/clark/example/deploy/dev/email/terragrunt.hcl:23,41-49: Unsupported attribute; This object does not have an attribute named "outputs"., and 2 other diagnostic(s)
/Users/clark/example/deploy/dev/email/terragrunt.hcl:23,41-49: Unsupported attribute; This object does not have an attribute named "outputs"., and 2 other diagnostic(s)

@clarklai Can you share your /Users/clark/example/deploy/dev/email/terragrunt.hcl configuration ?

[barryib]

@clarklai any news ? Do you still have this issue ?

[clarklai]

@barryib Here's the configuration for email/terragrunt.hcl:

terraform {
  source = "${get_terragrunt_dir()}/../../../core/email/module"
}

include {
  path = find_in_parent_folders()
}

dependency "platform" {
  config_path = "../platform"

  mock_outputs = {
    artifacts_bucket = "mock_artifacts_bucket_name"
    kms_key_id = "mock_kms_key_id"
    sns_dlq_name = "mock_sns_dlq_name"
  }

  mock_outputs_allowed_terraform_commands = ["validate"]
  skip_outputs = true
}

inputs = {
  artifacts_bucket = dependency.platform.outputs.artifacts_bucket
  kms_key_id = dependency.platform.outputs.kms_key_id
  sns_dlq_name = dependency.platform.outputs.sns_dlq_name
  root_dir = "${get_parent_terragrunt_dir()}/../.."
}

[yorinasub17]

Ah the issue is in this line:

mock_outputs_allowed_terraform_commands = ["validate"]

You are basically telling terragrunt that it can only use the mock_outputs if it is running terraform validate, but in the logs you were running terraform plan, so it doesn't read the mock_outputs.

You can resolve that particular error by adding plan to the list.

[clarklai]

You can resolve that particular error by adding plan to the list.

@yorinasub17 Yes, adding plan does remove the error.

However, does this mean that future terraform plan will continue to use the mock_outputs after terraform apply has been ran at least once?

[yorinasub17]

If you have skip_outputs = true, then yes. However, if you remove that line, then it will only use the mock_outputs when there are no outputs upstream.

[yorinasub17]

Going to close this now given that this is intended behavior.