From 3d63614d5f8360d305a7fa8e9e094d2268e53cb1 Mon Sep 17 00:00:00 2001
From: Moritz Zimmer <moritz.zmmr@gmail.com>
Date: Tue, 11 Feb 2020 10:20:51 +0100
Subject: [PATCH] support for cloudwatch event pattern as trigger

unified existing support of scheduled events with new pattern based
event trigger in new submodule

**this needs to be released as new major v5 version**

fixes #53
---
 README.md                                     |  6 +--
 .../README.md                                 |  4 +-
 .../example-with-cloudwatch-event/main.tf     | 37 ++++++++++++++
 .../test_function.zip                         |  0
 .../versions.tf                               |  0
 .../main.tf                                   | 27 ----------
 main.tf                                       | 11 +++--
 .../main.tf                                   |  5 ++
 modules/event/cloudwatch-event/variables.tf   | 49 +++++++++++++++++++
 .../versions.tf                               |  0
 .../cloudwatch-scheduled-event/variables.tf   | 14 ------
 11 files changed, 104 insertions(+), 49 deletions(-)
 rename examples/{example-with-cloudwatch-scheduled-event => example-with-cloudwatch-event}/README.md (73%)
 create mode 100644 examples/example-with-cloudwatch-event/main.tf
 rename examples/{example-with-cloudwatch-scheduled-event => example-with-cloudwatch-event}/test_function.zip (100%)
 rename examples/{example-with-cloudwatch-scheduled-event => example-with-cloudwatch-event}/versions.tf (100%)
 delete mode 100644 examples/example-with-cloudwatch-scheduled-event/main.tf
 rename modules/event/{cloudwatch-scheduled-event => cloudwatch-event}/main.tf (76%)
 create mode 100644 modules/event/cloudwatch-event/variables.tf
 rename modules/event/{cloudwatch-scheduled-event => cloudwatch-event}/versions.tf (100%)
 delete mode 100644 modules/event/cloudwatch-scheduled-event/variables.tf

diff --git a/README.md b/README.md
index c5943fd..aa93721 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ Terraform module to create AWS [Lambda](https://www.terraform.io/docs/providers/
 
 The following [event sources](https://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html) are supported (see [examples](#examples)):
 
-- [cloudwatch-scheduled-event](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-cloudwatch-scheduled-event): configures a [CloudWatch Event Rule](https://www.terraform.io/docs/providers/aws/r/cloudwatch_event_rule.html) to trigger the Lambda on a regular, scheduled basis
+- [cloudwatch-event](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-cloudwatch-event): configures a [CloudWatch Event Rule](https://www.terraform.io/docs/providers/aws/r/cloudwatch_event_rule.html) to trigger the Lambda by CloudWatch [event pattern](https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/CloudWatchEventsandEventPatterns.html) or on a regular, scheduled basis
 - [dynamodb](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-dynamodb-event): configures an [Event Source Mapping](https://www.terraform.io/docs/providers/aws/r/lambda_event_source_mapping.html) to trigger the Lambda by DynamoDb events
 - [kinesis](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-kinesis-event): configures an [Event Source Mapping](https://www.terraform.io/docs/providers/aws/r/lambda_event_source_mapping.html) to trigger the Lambda by Kinesis events
 - [s3](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-s3-event): configures permission to trigger the Lambda by S3
@@ -46,7 +46,7 @@ module "lambda" {
 
   // configurable event trigger, see examples
   event = {
-    type                = "cloudwatch-scheduled-event"
+    type                = "cloudwatch-event"
     schedule_expression = "rate(1 minute)"
   }
 
@@ -74,7 +74,7 @@ module "lambda" {
 
 ### Examples
 
-- [example-with-cloudwatch-scheduled-event](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-cloudwatch-scheduled-event)
+- [example-with-cloudwatch-event](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-cloudwatch-event)
 - [example-with-dynamodb-event](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-dynamodb-event)
 - [example-with-kinesis-event](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-kinesis-event)
 - [example-with-s3-event](https://github.com/spring-media/terraform-aws-lambda/tree/master/examples/example-with-s3-event)
diff --git a/examples/example-with-cloudwatch-scheduled-event/README.md b/examples/example-with-cloudwatch-event/README.md
similarity index 73%
rename from examples/example-with-cloudwatch-scheduled-event/README.md
rename to examples/example-with-cloudwatch-event/README.md
index c8d14be..77a08d9 100644
--- a/examples/example-with-cloudwatch-scheduled-event/README.md
+++ b/examples/example-with-cloudwatch-event/README.md
@@ -1,6 +1,6 @@
-# Example with CloudWatch scheduled event
+# Example with CloudWatch events
 
-Creates an AWS Lambda function triggered by a CloudWatch (scheduled) [event](https://docs.aws.amazon.com/lambda/latest/dg/with-scheduled-events.html).
+Creates AWS Lambda functions triggered by a CloudWatch [events](https://docs.aws.amazon.com/lambda/latest/dg/with-scheduled-events.html).
 
 ## requirements
 
diff --git a/examples/example-with-cloudwatch-event/main.tf b/examples/example-with-cloudwatch-event/main.tf
new file mode 100644
index 0000000..eeb27ea
--- /dev/null
+++ b/examples/example-with-cloudwatch-event/main.tf
@@ -0,0 +1,37 @@
+provider "aws" {
+  region = "eu-west-1"
+}
+
+module "lambda-scheduled" {
+  source        = "../../"
+  description   = "Example AWS Lambda using go with cloudwatch scheduled event trigger"
+  filename      = "${path.module}/test_function.zip"
+  function_name = "tf-example-go-basic"
+  handler       = "example-lambda-func"
+  runtime       = "go1.x"
+
+  event = {
+    type                = "cloudwatch-event"
+    schedule_expression = "rate(1 minute)"
+  }
+}
+
+module "lambda-pattern" {
+  source        = "../../"
+  description   = "Example AWS Lambda using go with cloudwatch event pattern trigger"
+  filename      = "${path.module}/test_function.zip"
+  function_name = "tf-example-go-basic"
+  handler       = "example-lambda-func"
+  runtime       = "go1.x"
+
+  event = {
+    type          = "cloudwatch-event"
+    event_pattern = <<PATTERN
+    {
+      "detail-type": [
+        "AWS Console Sign In via CloudTrail"
+      ]
+    }
+    PATTERN
+  }
+}
diff --git a/examples/example-with-cloudwatch-scheduled-event/test_function.zip b/examples/example-with-cloudwatch-event/test_function.zip
similarity index 100%
rename from examples/example-with-cloudwatch-scheduled-event/test_function.zip
rename to examples/example-with-cloudwatch-event/test_function.zip
diff --git a/examples/example-with-cloudwatch-scheduled-event/versions.tf b/examples/example-with-cloudwatch-event/versions.tf
similarity index 100%
rename from examples/example-with-cloudwatch-scheduled-event/versions.tf
rename to examples/example-with-cloudwatch-event/versions.tf
diff --git a/examples/example-with-cloudwatch-scheduled-event/main.tf b/examples/example-with-cloudwatch-scheduled-event/main.tf
deleted file mode 100644
index b15a220..0000000
--- a/examples/example-with-cloudwatch-scheduled-event/main.tf
+++ /dev/null
@@ -1,27 +0,0 @@
-provider "aws" {
-  region = "eu-west-1"
-}
-
-module "lambda" {
-  source        = "../../"
-  description   = "Example AWS Lambda using go with cloudwatch scheduled event trigger"
-  filename      = "${path.module}/test_function.zip"
-  function_name = "tf-example-go-basic"
-  handler       = "example-lambda-func"
-  runtime       = "go1.x"
-
-  event = {
-    type                = "cloudwatch-scheduled-event"
-    schedule_expression = "rate(1 minute)"
-  }
-
-  tags = {
-    key = "value"
-  }
-
-  environment = {
-    variables = {
-      key = "value"
-    }
-  }
-}
diff --git a/main.tf b/main.tf
index 64a5a2c..b2b4487 100644
--- a/main.tf
+++ b/main.tf
@@ -14,11 +14,16 @@ module "lambda" {
   vpc_config                     = var.vpc_config
 }
 
-module "event-cloudwatch-scheduled-event" {
-  source = "./modules/event/cloudwatch-scheduled-event"
-  enable = lookup(var.event, "type", "") == "cloudwatch-scheduled-event" ? true : false
+module "event-cloudwatch" {
+  source = "./modules/event/cloudwatch-event"
+  enable = lookup(var.event, "type", "") == "cloudwatch-event" ? true : false
 
   lambda_function_arn = module.lambda.arn
+  description         = lookup(var.event, "description", "")
+  event_pattern       = lookup(var.event, "event_pattern", "")
+  is_enabled          = lookup(var.event, "is_enabled", true)
+  name                = lookup(var.event, "name", null)
+  name_prefix         = lookup(var.event, "name_prefix", null)
   schedule_expression = lookup(var.event, "schedule_expression", "")
 }
 
diff --git a/modules/event/cloudwatch-scheduled-event/main.tf b/modules/event/cloudwatch-event/main.tf
similarity index 76%
rename from modules/event/cloudwatch-scheduled-event/main.tf
rename to modules/event/cloudwatch-event/main.tf
index 14f260a..39a6ff8 100644
--- a/modules/event/cloudwatch-scheduled-event/main.tf
+++ b/modules/event/cloudwatch-event/main.tf
@@ -9,6 +9,11 @@ resource "aws_lambda_permission" "cloudwatch" {
 
 resource "aws_cloudwatch_event_rule" "lambda" {
   count               = var.enable ? 1 : 0
+  description         = var.description
+  event_pattern       = var.event_pattern
+  is_enabled          = var.is_enabled
+  name                = var.name
+  name_prefix         = var.name_prefix
   schedule_expression = var.schedule_expression
 }
 
diff --git a/modules/event/cloudwatch-event/variables.tf b/modules/event/cloudwatch-event/variables.tf
new file mode 100644
index 0000000..57c9aa9
--- /dev/null
+++ b/modules/event/cloudwatch-event/variables.tf
@@ -0,0 +1,49 @@
+# ---------------------------------------------------------------------------------------------------------------------
+# REQUIRED PARAMETERS
+# You must provide a value for each of these parameters.
+# ---------------------------------------------------------------------------------------------------------------------
+
+variable "lambda_function_arn" {
+  description = "The Amazon Resource Name (ARN) identifying the Lambda Function trigger by CloudWatch"
+}
+
+# ---------------------------------------------------------------------------------------------------------------------
+# OPTIONAL PARAMETERS
+# These parameters have reasonable defaults.
+# ---------------------------------------------------------------------------------------------------------------------
+
+variable "description" {
+  default     = ""
+  description = "The description of the rule. "
+}
+
+variable "enable" {
+  default     = false
+  description = "Conditionally enables this module (and all it's ressources)."
+}
+
+variable "event_pattern" {
+  default     = ""
+  description = "(Required, if schedule_expression isn't specified) Event pattern described a JSON object."
+}
+
+variable "is_enabled" {
+  default     = true
+  description = "Whether the rule should be enabled (defaults to true)."
+}
+
+variable "name" {
+  default     = ""
+  description = "The rule's name. By default generated by Terraform."
+}
+
+variable "name_prefix" {
+  default     = ""
+  description = "The rule's name. Conflicts with name."
+}
+
+variable "schedule_expression" {
+  default     = ""
+  description = "(Required, if event_pattern isn't specified) Scheduling expression for triggering the Lambda Function using CloudWatch events. For example, cron(0 20 * * ? *) or rate(5 minutes)."
+}
+
diff --git a/modules/event/cloudwatch-scheduled-event/versions.tf b/modules/event/cloudwatch-event/versions.tf
similarity index 100%
rename from modules/event/cloudwatch-scheduled-event/versions.tf
rename to modules/event/cloudwatch-event/versions.tf
diff --git a/modules/event/cloudwatch-scheduled-event/variables.tf b/modules/event/cloudwatch-scheduled-event/variables.tf
deleted file mode 100644
index 73b962e..0000000
--- a/modules/event/cloudwatch-scheduled-event/variables.tf
+++ /dev/null
@@ -1,14 +0,0 @@
-variable "enable" {
-  description = "Conditionally enables this module (and all it's ressources)."
-  type        = bool
-  default     = false
-}
-
-variable "lambda_function_arn" {
-  description = "The Amazon Resource Name (ARN) identifying the Lambda Function trigger by CloudWatch"
-}
-
-variable "schedule_expression" {
-  description = "Scheduling expression for triggering the Lambda Function using CloudWatch events. For example, cron(0 20 * * ? *) or rate(5 minutes)."
-}
-