From 4603283904a87a83ff8f04d25daa035acde1a49a Mon Sep 17 00:00:00 2001
From: Kyle Kotowick <kotowick@invictonlabs.com>
Date: Sun, 3 Oct 2021 10:53:23 -0400
Subject: [PATCH] Update value-changed module version and usage

---
 main.tf      | 32 ++++++++++++++++++++------------
 variables.tf |  2 +-
 2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/main.tf b/main.tf
index 76e2ed2..f604433 100644
--- a/main.tf
+++ b/main.tf
@@ -1,6 +1,6 @@
 module "state" {
   source  = "Invicton-Labs/get-state/null"
-  version = "0.2.1"
+  version = "~> 0.2.1"
 }
 
 locals {
@@ -10,29 +10,37 @@ locals {
   }
 }
 
+// This module tracks when the trigger has changed, which it uses to determine if the create command should be run
 module "trigger_changed_create" {
-  source  = "Invicton-Labs/value-changed/null"
-  version = "0.1.1"
-  value   = local.trigger
-  depends = [
+  source                        = "Invicton-Labs/value-changed/null"
+  version                       = "~> 0.2.0"
+  value                         = local.trigger
+  consider_first_use_as_changed = true
+  save_depends_on = [
     data.aws_lambda_invocation.shell_create
   ]
 }
 
+// This module also tracks when the trigger has changed, which it uses to determine if the destroy command should be run
 module "trigger_changed_destroy" {
   source  = "Invicton-Labs/value-changed/null"
-  version = "0.1.1"
+  version = "~> 0.2.0"
   value   = local.trigger
-  depends = [
+  // Don't try to destroy anything if there's no value in state yet
+  consider_first_use_as_changed = false
+  save_depends_on = [
     data.aws_lambda_invocation.shell_destroy
   ]
 }
 
 locals {
   create = module.trigger_changed_create.changed
-  // Only run the destroy if the inputs have changed since the last successful run AND the old value wasn't null (which would imply that this is the first create; there's nothing to destroy) AND a destroy command has been provided AND the last successful trigger is the same as the last stored trigger
-  destroy = module.trigger_changed_destroy.changed && module.trigger_changed_destroy.old_value != null && var.destroy_command != null && (module.state_keeper.existing_value != null ? module.state_keeper.existing_value.trigger == module.trigger_changed_destroy.old_value : false)
-  // The uuid() function waits for the apply phase before it knows the value
+  // Only run the destroy if the inputs have changed since the last successful run AND a destroy command has been provided AND the last successful trigger is the same as the last stored trigger
+  destroy = module.trigger_changed_destroy.changed && var.destroy_command != null && (module.state_keeper.existing_value != null ? module.state_keeper.existing_value.trigger == module.trigger_changed_destroy.old_value : false)
+  // The uuid() function waits for the apply phase before it knows the value.
+  // We only want to force it to wait for the apply phase if something actually needs
+  // to be created/destroyed. Otherwise, run it during the plan phase (with a fake value)
+  // so it doesn't appear as "will be read" in the plan.
   wait_for_apply_create  = local.create ? uuid() : true
   wait_for_apply_destroy = local.destroy ? uuid() : true
 }
@@ -43,7 +51,7 @@ data "aws_lambda_invocation" "shell_create" {
   depends_on = [
     var.lambda_shell_module,
     data.aws_lambda_invocation.shell_destroy,
-    module.trigger_changed_destroy
+    module.trigger_changed_destroy,
   ]
   // Force it to wait for the apply step, and also wait for the destroy to complete if the destroy should be done
   function_name = local.wait_for_apply_create == null ? var.lambda_shell_module.invicton_labs_lambda_shell_arn : var.lambda_shell_module.invicton_labs_lambda_shell_arn
@@ -83,7 +91,7 @@ locals {
 // This keeps the output value in state until it's re-created
 module "state_keeper" {
   source  = "Invicton-Labs/state-keeper/null"
-  version = "0.1.1"
+  version = "~> 0.1.1"
   // This convoluted expression just forces the shell_destroy data source to actually execute. Since the value isn't being returned anywhere, 
   // the data source won't be executed unless you tell it to use the output value in order to evaluate a conditional expression like this ternary one.
   input               = local.destroy ? (data.aws_lambda_invocation.shell_create.result == null ? local.create_result : local.create_result) : local.create_result
diff --git a/variables.tf b/variables.tf
index 2f0a08b..e1ef207 100644
--- a/variables.tf
+++ b/variables.tf
@@ -1,5 +1,5 @@
 variable "lambda_shell_module" {
-  description = "An `Invicton-Labs/lambda-shell/aws` module (https://registry.terraform.io/modules/Invicton-Labs/request-signer/aws). Pass the entire module in as this parameter (e.g. `lambda_shell_module = module.lambda-shell`)."
+  description = "An `Invicton-Labs/lambda-shell/aws` module (https://registry.terraform.io/modules/Invicton-Labs/lambda-shell/aws). Pass the entire module in as this parameter (e.g. `lambda_shell_module = module.lambda-shell`)."
   type = object({
     invicton_labs_lambda_shell_arn = string
   })