Flatten nested map of maps to a single map with dotted notation

Terraform
1

I’m reading yaml file contents using yamldecode function, but the yaml file rather gets deep and need to pass the contents of the file to a dynamic block. I can’t find a way to merge/flatten map of maps with dotted notation.

Yaml file content:

foo:
     pleh: help
stuff:
     foo:
         foo-2:
              foo-3: bar
     bar: foo

Expected output:

"foo.pleh": help
"stuff.foo.foo-2.foo-3: bar"
"stuf.bar": foo

Terraform usage:

variable "chart_vars" {
  type = map(string)
}

dynamic "set" {
  for_each = var.chart_vars
   content {
    name  = set.key
    value = set.value
  }
}

Is there any way to do this in terraform? Yaml file contents and depth are unknown i.e., file will keep growing as more value are added.

Thanks in advance!

2

Hi @gowtham .

Sorry for raising this old one, but have you ever found a solution to this? I’m facing this exact challenge at the moment and so far I’m failing to find the answer.

Thanks!

3

No, there is no way to write this transformation directly in Terraform syntax.

But, neither do you have to do this, as the helm_release resource allows you to pass values YAML as is.

4

Unfortunately, my scenario was to set_sensitive {} for every key value pair.

I ended up with yamldecode + external_data provider with a bash script allowing the transformation in question.