when reusing an existing AWS instance make sure the alarms are attached

plugins/TestRunner/Aws/CloudWatch.php

@@ -21,16 +21,33 @@ class CloudWatch
      */
     private $config;
 
+    /**
+     * @var CloudWatchClient
+     */
+    private $client;
+
     public function __construct(Config $awsConfig)
     {
         $this->config = $awsConfig;
+        $this->client = $this->getCloudWatchClient();
     }
 
-    public function terminateInstanceIfIdleForTooLong($instanceIds)
+    public function hasAssignedAlarms($instanceIds)
     {
-        $client = $this->getCloudWatchClient();
+        $result = $this->client->describeAlarmsForMetric(array(
+            'MetricName' => 'CPUUtilization',
+            'Namespace'  => $this->getNamespace(),
+            'Dimensions' => $this->getDimensions($instanceIds)
+        ));
 
-        $client->putMetricAlarm(array(
+        $metricAlarms = $result->getPath('MetricAlarms');
+
+        return !empty($metricAlarms);
+    }
+
+    public function terminateInstanceIfIdleForTooLong($instanceIds)
+    {
+        $this->client->putMetricAlarm(array(
             'AlarmName' => 'TerminateInstanceBecauseIdle',
             'AlarmDescription' => 'Terminate instances if CPU is on average < 10% for 5 minutes in a row 8 times consecutively',
             'ActionsEnabled' => true,
@@ -48,7 +65,7 @@ class CloudWatch
             'ComparisonOperator' => ComparisonOperator::LESS_THAN_THRESHOLD,
         ));
 
-        $client->putMetricAlarm(array(
+        $this->client->putMetricAlarm(array(
             'AlarmName' => 'TerminateInstanceIfStatusCheckFails',
             'AlarmDescription' => 'Terminate instances in case two status check fail within one minute',
             'ActionsEnabled' => true,

plugins/TestRunner/Aws/Instance.php

@@ -63,6 +63,9 @@ class Instance
         if (!empty($reservations)) {
             $host = $this->getHostFromDescribedInstances($instances);
 
+            $instanceIds = $instances->getPath('Reservations/*/Instances/*/InstanceId');
+            $this->verifySetup($instanceIds);
+
             return $host;
         }
     }
@@ -96,15 +99,15 @@ class Instance
 
         $instanceIds = $result->getPath('Instances/*/InstanceId');
 
+        $this->client->waitUntilInstanceRunning(array(
+            'InstanceIds' => $instanceIds,
+        ));
+
         return $instanceIds;
     }
 
     public function setup($instanceIds)
     {
-        $this->client->waitUntilInstanceRunning(array(
-            'InstanceIds' => $instanceIds,
-        ));
-
         $awsCloudWatch = new CloudWatch($this->config);
         $awsCloudWatch->terminateInstanceIfIdleForTooLong($instanceIds);
 
@@ -120,6 +123,17 @@ class Instance
         return $host;
     }
 
+    public function verifySetup($instanceIds)
+    {
+        $awsCloudWatch = new CloudWatch($this->config);
+        $hasAlarms = $awsCloudWatch->hasAssignedAlarms($instanceIds);
+
+        if (!$hasAlarms) {
+            return $this->setup($instanceIds);
+        }
+
+    }
+
     /**
      * @param \Guzzle\Service\Resource\Model $resources
      * @return mixed