From 75331038bee06d0cf8d0f0f6f8afc5ec6cfae92c Mon Sep 17 00:00:00 2001
From: cfln123 <c.neto@base2services.com>
Date: Mon, 16 Sep 2024 18:35:52 -0300
Subject: [PATCH] Add support for insight metrics

---
 lib/cfnguardian/compile.rb           | 8 +++++---
 lib/cfnguardian/display_formatter.rb | 2 ++
 lib/cfnguardian/models/alarm.rb      | 2 ++
 lib/cfnguardian/resources/base.rb    | 2 +-
 lib/cfnguardian/stacks/resources.rb  | 9 +++++----
 5 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/lib/cfnguardian/compile.rb b/lib/cfnguardian/compile.rb
index c6c3a02..a6b2e85 100644
--- a/lib/cfnguardian/compile.rb
+++ b/lib/cfnguardian/compile.rb
@@ -190,9 +190,11 @@ def validate_resources()
       @resources.each do |resource|
         case resource.type
         when 'Alarm'
-          %w(metric_name namespace).each do |property|
-            if resource.send(property).nil?
-              @errors << "CfnGuardian::AlarmPropertyError - alarm #{resource.name} for resource #{resource.resource_id} has nil value for property #{property.to_camelcase}. This could be due to incorrect spelling of a default alarm name or missing property #{property.to_camelcase} on a new alarm."
+          if resource.metrics.nil?
+            %w(metric_name namespace).each do |property|
+              if resource.send(property).nil?
+                @errors << "CfnGuardian::AlarmPropertyError - alarm #{resource.name} for resource #{resource.resource_id} has nil value for property #{property.to_camelcase}. This could be due to incorrect spelling of a default alarm name or missing property #{property.to_camelcase} on a new alarm."
+              end
             end
           end
         when 'Check'
diff --git a/lib/cfnguardian/display_formatter.rb b/lib/cfnguardian/display_formatter.rb
index 7672a5d..e10c58e 100644
--- a/lib/cfnguardian/display_formatter.rb
+++ b/lib/cfnguardian/display_formatter.rb
@@ -20,6 +20,7 @@ def alarms()
           ['ResourceName', alarm.resource_name],
           ['Enabled', alarm.enabled],
           ['MetricName', alarm.metric_name],
+          ['Metrics', alarm.metrics],
           ['Dimensions', alarm.dimensions],
           ['Threshold', alarm.threshold],
           ['Period', alarm.period],
@@ -60,6 +61,7 @@ def compare_alarms(metric_alarms)
           ['ResourceName', alarm.resource_name, alarm.resource_name],
           ['Enabled', alarm.enabled, true],
           ['MetricName', alarm.metric_name, metric_alarm.metric_name],
+          ['Metrics', alarm.metrics],
           ['Dimensions', alarm.dimensions, dimensions],
           ['Threshold', alarm.threshold.to_f, metric_alarm.threshold],
           ['Period', alarm.period, metric_alarm.period],
diff --git a/lib/cfnguardian/models/alarm.rb b/lib/cfnguardian/models/alarm.rb
index 6c6a12f..710c8ae 100644
--- a/lib/cfnguardian/models/alarm.rb
+++ b/lib/cfnguardian/models/alarm.rb
@@ -13,6 +13,7 @@ class BaseAlarm
         :metric_name,
         :namespace,
         :dimensions,
+        :metrics,
         :threshold,
         :period,
         :evaluation_periods,
@@ -39,6 +40,7 @@ def initialize(resource)
         @metric_name = nil
         @namespace = nil
         @dimensions = nil
+        @metrics = nil
         @threshold = 0
         @period = 60
         @evaluation_periods = 1
diff --git a/lib/cfnguardian/resources/base.rb b/lib/cfnguardian/resources/base.rb
index 5f440cc..c6d6505 100644
--- a/lib/cfnguardian/resources/base.rb
+++ b/lib/cfnguardian/resources/base.rb
@@ -112,7 +112,7 @@ def get_alarms(group,overides={})
       
       # String interpolation for alarm dimensions
       @alarms.each do |alarm|
-        next if alarm.dimensions.nil?
+        next if alarm.dimensions.nil? || ! alarm.metrics.nil?
         alarm.dimensions.each do |k,v|
           if v.is_a?(String) && v.match?(/^\${Resource::.*[A-Za-z]}$/)
             resource_key = v.tr('${}', '').split('Resource::').last
diff --git a/lib/cfnguardian/stacks/resources.rb b/lib/cfnguardian/stacks/resources.rb
index 70462d8..eb4c2eb 100644
--- a/lib/cfnguardian/stacks/resources.rb
+++ b/lib/cfnguardian/stacks/resources.rb
@@ -40,13 +40,14 @@ def add_alarm(alarm)
             AlarmDescription "Guardian alarm #{alarm.name} for the resource #{alarm.resource_id} in alarm group #{alarm.group}"
             AlarmName CfnGuardian::CloudWatch.get_alarm_name(alarm)
             ComparisonOperator alarm.comparison_operator
+            Metrics alarm.metrics unless alarm.metrics.nil?
             Dimensions alarm.dimensions.map {|k,v| {Name: k, Value: v}} unless alarm.dimensions.nil?
             EvaluationPeriods alarm.evaluation_periods
-            Statistic alarm.statistic if alarm.extended_statistic.nil?
-            Period alarm.period
+            Statistic alarm.statistic if alarm.extended_statistic.nil? && alarm.metrics.nil?
+            Period alarm.period if alarm.metrics.nil?
             Threshold alarm.threshold
-            MetricName alarm.metric_name
-            Namespace alarm.namespace
+            MetricName alarm.metric_name if alarm.metrics.nil?
+            Namespace alarm.namespace if alarm.metrics.nil?
             AlarmActions actions
             OKActions actions
             TreatMissingData alarm.treat_missing_data unless alarm.treat_missing_data.nil?