S3-Bucket - make templated logging bucket name more flexible

[westonplatter]

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Describe the Feature

While using the s3-bucket component and trying to add logging to it, I want to use a logging_bucket_name_rendering_template format to work when null-label's tenant and environment are null. When I tried using the suggested format for when only tenant is null, I ran into an error with terraform not being able to format a null value with %s -- this is consistent with tf format syntax section docs (see last paragraph in that section).

See the example below.

I believe the required feature change is to remove any null values in the bucket_name line,

│ Error: Error in function call
│ 
│   on ../../modules/example/main.tf line 30, in locals:
│   30:     final_bucket_name = format("%s-%s-%s-%%s", var.test_namespace, var.test_tenant, var.test_environment, var.test_stage, var.test_logging_bucket_name)
│     ├────────────────
│     │ while calling format(format, args...)
│     │ var.test_environment is "myEnviornment"
│     │ var.test_logging_bucket_name is "myLoggingBucketName"
│     │ var.test_namespace is "myNameSpace"
│     │ var.test_stage is "myStage"
│     │ var.test_tenant is null
│ 
│ Call to function "format" failed: unsupported value for "%s" at 3: null value cannot be formatted.
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Expected Behavior

When null values are present in the null-label settings (eg, when environment is null), the format function should still generate a logging bucket name.

Use Case

NA

Describe Ideal Solution

Adjust this line to remove nulls before calling the format function.

Something like this,

locals {
    non_null_values = compact([var.test_namespace, var.test_tenant, var.test_environment, var.test_stage, var.test_logging_bucket_name])
    final_bucket_name = format("%s-%s-%s-%%s", local.non_null_values)
}

If I can get feedback on a viable solution, I'm happy to submit a PR.

Alternatives Considered

Manually set the logging bucket as needed.

Additional Context

variable "test_namespace" {
  type        = string
  description = "The namespace to use for the test"
  default = "myNameSpace"
}
  
variable "test_tenant" {
  type        = string
  description = "The tenant to use for the test"
  default     = null
}

variable "test_environment" {
  type        = string
  description = "The environment to use for the test"
  default     = "myEnvironment"
}

variable "test_stage" {
  type        = string
  description = "The stage to use for the test"
  default     = "myStage"
}

variable "test_logging_bucket_name" {
    type        = string
    description = "The logging bucket name to use for the test"
}

locals {
    non_null_values = compact([var.test_namespace, var.test_tenant, var.test_environment, var.test_stage, var.test_logging_bucket_name])
    final_bucket_name = format("%s-%s-%s-%%s", local.non_null_values)
}

output "final_bucket_name" {
  value = local.final_bucket_name
}

[Nuru]

The format recommended in the variable description for when not using tenant is wrong. What is needed is a correction to the documentation, not the code. The correct format is

"%s-%[3]s-%[4]s-%[5]s"

[westonplatter]

@Nuru thanks for the feedback. Will try the suggestion and check back.