json template reference to an object variable;

Question

I have a JSON template used for a resource in the terraform project. My problem is that I cannot successfully reference the value from a parameters block in my json template when it is deployed in Azure Portal logic app code view

For my resource (azapi_resource type Microsoft.Logic/workflows@2019-05-01, I have this body:

body = jsonencode({
    properties = {
      definition = jsondecode(templatefile("${path.module}/xyz.json",
        {
          .
          .
          uri = "https://****"
          requestBody      = var.params_obj
      }))
      parameters = {
        .
        .
        uri = { value = "https://****" } #it is a string;
        reqBody    = { value = var.params_obj  #it is an object
      }
      state = "Enabled"
    }
  })

In my variables.tf I have the var declared:

variable "params_obj" {
  type = object({
    pipeline = object({
      calculation_date = string
      name             = string
      abc = optional(object({
          .
          .
        })
    })
  })
}

In my sample json xyz.json I have to reference the var.params_obj but is not working and it is putting in Logic App Code View as it is and not the Object values of my variable.

In my json sample xyz.json I tried to reference as below:

         "inputs": {
            "subscribe": {
                "body": "${reqBody}" #not working; I tried also with "[parameters('reqBody')]"  #I tried with another forms... not working;
                ,
                "method": "POST",
                "uri": "${uri}"   #it works to reference the string uri value;
            "unsubscribe": {}

My question is how to reference that reqBody correctly in my json template? because it is a bit strange.

My sample json contains definition and schema for Microsoft.Logic/workflows;

 "$schema": "https://schema.management.azure.com/providers/Microsoft.Logic/schemas/2016-06-01/workflowdefinition.json#" 

Answer 1

Since you didn't really provide a clear example that I could use to reproduce I have taken a guess at what you are trying to achieve and simplified the problem.

Assuming you want the request body as a valid json string in the template you need to use the jsondecode function to turn the var into a json string before you try to use it in the template

main.tf

variable "params_obj" {
  type = object({
    pipeline = object({
      calculation_date = string
      name             = string
      abc              = optional(object({
        foo = string
      }))
    })
  })
  default = {
    pipeline = {
      calculation_date = "monday"
      name = "chris"
    }
  }
}

output "this" {
  value = templatefile("mytemp.tftpl", {
    reqBody = jsonencode(var.params_obj)
    uri = "bar"
  })
}

template

{
    "inputs": {
             "subscribe": {
                 "body": ${reqBody},
                 "method": "POST",
                 "uri": "${uri}"
             },
             "unsubscribe": {}
   }
}

OUTPUT

Outputs:

this = <<EOT
{
    "inputs": {
             "subscribe": {
                 "body": "{"pipeline":{"abc":null,"calculation_date":"monday","name":"chris"}}" ,
                 "method": "POST",
                 "uri": "bar"
             },
             "unsubscribe": {}
   }
}
EOT

without using jsondecode function and trying to pass the var directly to template I would get the error

│ Error: Error in function call
│
│   on main.tf line 20, in output "this":
│   20:   value = templatefile("mytemp.tftpl", {
│   21:     reqBody = var.params_obj
│   22:     uri = "bar"
│   23:   })
│     ├────────────────
│     │ while calling templatefile(path, vars)
│     │ var.params_obj is object with 1 attribute "pipeline"
│
│ Call to function "templatefile" failed: mytemp.tftpl:4,29-36: Invalid template interpolation value; Cannot include the given value in a string template: string required..