Possible fix for this issue #306

It allows to use already created role in CloudWatch event which trigger StepFunctions

Author: Taras Buchko

lib/deploy/events/cloudWatchEvent/compileCloudWatchEventEvents.js

@@ -22,6 +22,7 @@ module.exports = {
             let Description;
             let Name;
             let EventBusName;
+            let IamRole;
 
             if (typeof eventRule === 'object') {
               if (!eventRule.event) {
@@ -43,6 +44,7 @@ module.exports = {
               Description = eventRule.description;
               Name = eventRule.name;
               EventBusName = eventRule.eventBusName;
+              IamRole = eventRule.iamRole;
 
               if (Input && InputPath) {
                 const errorMessage = [
@@ -92,12 +94,12 @@ module.exports = {
                     ${InputPath ? `"InputPath": "${InputPath.replace(/\r?\n/g, '')}",` : ''}
                     "Arn": { "Ref": "${stateMachineLogicalId}" },
                     "Id": "${cloudWatchId}",
-                    "RoleArn": {
+                    ${IamRole ? `"RoleArn":"${IamRole}"`:`"RoleArn": {
                       "Fn::GetAtt": [
                         "${cloudWatchIamRoleLogicalId}",
                         "Arn"
                       ]
-                    }
+                    }`}
                   }]
                 }
               }
@@ -146,12 +148,17 @@ module.exports = {
               [cloudWatchLogicalId]: JSON.parse(cloudWatchEventRuleTemplate),
             };
 
-            const newPermissionObject = {
-              [cloudWatchIamRoleLogicalId]: JSON.parse(iamRoleTemplate),
-            };
+            const objectsToMerge = [newCloudWatchEventRuleObject]
+
+            if(!IamRole){
+              const newPermissionObject = {
+                [cloudWatchIamRoleLogicalId]: JSON.parse(iamRoleTemplate),
+              };
+              
+              objectsToMerge.push(newPermissionObject)
+            }
 
-            _.merge(this.serverless.service.provider.compiledCloudFormationTemplate.Resources,
-              newCloudWatchEventRuleObject, newPermissionObject);
+            _.merge(this.serverless.service.provider.compiledCloudFormationTemplate.Resources, ...objectsToMerge);
           }
         });
       }