Fix for when this module is used in an iterative environment

In the use case documented in the README.md, if there are multiple ASGs,
and this module is then called iteratively, each iteration will now
correctly have its own output.

This may also be fixing #3.

In local testing, for a new ASG being added to a pool of existing ASGs,
the recorded output files are showing the correct values, with the string
null being recorded for the new ASG (which is correct in this context).

README.md

@@ -65,8 +65,8 @@ module "current_desired_capacity" {
 
 | Name | Version |
 |------|---------|
-| <a name="provider_external"></a> [external](#provider\_external) | ~> 2.0 |
-| <a name="provider_local"></a> [local](#provider\_local) | ~> 2.0 |
+| <a name="provider_external"></a> [external](#provider\_external) | 2.1.0 |
+| <a name="provider_local"></a> [local](#provider\_local) | 2.1.0 |
 
 ## Modules
 

main.tf

@@ -1,11 +1,31 @@
+locals {
+  joined_aws_cli_command = join(" ", var.aws_cli_commands)
+  output_file = format(
+    "%s/temp/results-%s.json",
+    path.module,
+    md5(
+      join(
+        "-",
+        [
+          var.assume_role_arn,
+          var.role_session_name,
+          local.joined_aws_cli_command,
+          var.aws_cli_query,
+          var.debug_log_filename
+        ]
+      )
+    )
+  )
+}
+
 data "external" "awscli_program" {
   program = [format("%s/scripts/awsWithAssumeRole.sh", path.module)]
   query = {
     assume_role_arn    = var.assume_role_arn
     role_session_name  = var.role_session_name
-    aws_cli_commands   = join(" ", var.aws_cli_commands)
+    aws_cli_commands   = local.joined_aws_cli_command
     aws_cli_query      = var.aws_cli_query
-    output_file        = format("%s/temp/results.json", path.module)
+    output_file        = local.output_file
     debug_log_filename = var.debug_log_filename
   }
 }

scripts/awsWithAssumeRole.sh

@@ -44,6 +44,9 @@ fi
 # Make sure output file directory exists
 mkdir -p "$(dirname ${OUTPUT_FILE})"
 
+# Make sure output file does not exist
+rm -f "${OUTPUT_FILE}"
+
 # Disable any assigned pager
 export AWS_PAGER=""