Closes #208, #207, #206, #182, #149, #72, #15

(cherry picked from commit 8de328df79ccf52b8d612c625891555808c2fa0e)

lib/template.js

@@ -1,4 +1,4 @@
-'use strict';
+
 
 const cf = require('@mapbox/cloudfriend');
 const path = require('path');
@@ -35,9 +35,12 @@ const pkg = require(path.resolve(__dirname, '..', 'package.json'));
  * to specify this in order to differentiate the resources.
  * @param {String} [options.family] - the name of the the task definition family
  * that watchbot will create revisions of.
- * @param {Number|ref} [options.workers=1] - the maximum number of worker
- * containers that can be launched to process jobs concurrently. This parameter
- * can be provided as either a number or a reference, i.e. `{"Ref": "..."}`.
+ * @param {Number|ref} [options.maxSize=1] - the maximum size for the service to
+ * scale up to. This parameter can be provided as either a number or a reference,
+ * i.e. `{"Ref": "..."}`.
+  * @param {Number|ref} [options.minSize=1] - the minimum size for the service to
+ * scale down to. This parameter can be provided as either a number or a reference,
+ * i.e. `{"Ref": "..."}`.
  * @param {String} [options.mounts=''] - if your worker containers need to mount
  * files or folders from the host EC2 file system, specify those mounts with this parameter.
  * A single persistent mount point can be specified as `{host location}:{container location}`,
@@ -97,6 +100,10 @@ const pkg = require(path.resolve(__dirname, '..', 'package.json'));
  * of 1-minute periods before an alarm is triggered. The default is 1 period, or
  * 1 minute. This parameter can be provided as either a number or a reference,
  * i.e. `{"Ref": "..."}`.
+ * @param {Number|ref} [options.deadLetterThreshold=10] - Use this parameter to
+ * control the duration that the number of times a message is delivered to the
+ * source queue before being moved to the dead-letter queue. This parameter
+ * can be provided as either a number or a reference, i.e. `{"Ref": "..."}`.
  */
 module.exports = (options = {}) => {
   ['service', 'serviceVersion', 'command', 'cluster'].forEach((required) => {
@@ -111,14 +118,15 @@ module.exports = (options = {}) => {
       env: {},
       messageTimeout: 600,
       messageRetention: 1209600,
-      workers: 1,
+      maxSize: 1,
       mounts: '',
       privileged: false,
       family: options.service,
       errorThreshold: 10,
       alarmThreshold: 40,
       alarmPeriods: 24,
-      failedPlacementAlarmPeriods: 1
+      failedPlacementAlarmPeriods: 1,
+			deadletterThreshold: 10
     },
     options
   );
@@ -210,7 +218,7 @@ module.exports = (options = {}) => {
       MessageRetentionPeriod: options.messageRetention,
       RedrivePolicy: {
         deadLetterTargetArn: cf.getAtt(prefixed('DeadLetterQueue'), 'Arn'),
-        maxReceiveCount: 10
+        maxReceiveCount: options.deadletterThreshold
       }
     }
   };
@@ -439,8 +447,8 @@ module.exports = (options = {}) => {
         '/',
         cf.getAtt(prefixed('Service'), 'Name')
       ]),
-      MinCapacity: 0,
-      MaxCapacity: options.workers,
+      MinCapacity: options.minSize,
+      MaxCapacity: options.maxSize,
       RoleARN: cf.getAtt(prefixed('ScalingRole'), 'Arn')
     }
   };
@@ -457,7 +465,7 @@ module.exports = (options = {}) => {
         MetricAggregationType: 'Average',
         StepAdjustments: [
           {
-            ScalingAdjustment: Math.ceil(options.workers / 10),
+            ScalingAdjustment: Math.ceil(options.maxSize / 10),
             MetricIntervalLowerBound: 0.0
           }
         ]