Repository: serverless/serverless (JavaScript) — Bug Fix

Issue:
Amazon EventBridge not compatible with partner event sources
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# This is a Bug Report

## Description

When deploying an AWS Lambda that is triggered by Amazon EventBridge using a partner event source (such as segment.com) a CloudFormation error occurs that the event bus cannot be found. This error appears to be caused by the way the event bus ARN is parsed by Serverless, detailed below.

Configuration:

```yaml
# ...
functions:
  # ...
  create-request:
    handler: functions/handler.createRequest
    events:
      - eventBridge:
          eventBus: 'arn:aws:events:us-east-1:XXXXXXXXXXXX:event-bus/aws.partner/segment.com/XXXXXXXXXX'
          pattern:
            source:
              - 'aws.partner/segment.com/XXXXXXXXXX'
            detail:
              event:
                - 'My Event'
              type:
                - 'track'
# ...
```

The deployment error that is displayed in the console is:

```
Failed to create resource. Event bus XXXXXXXXXX does not exist. See details in CloudWatch Log: 2019/08/06/[$LATEST][...].
```

In the current implementation, Serverless parses out the event bus ARN so it only includes the text after the last `/` character. In the case of partner sources, a portion of the ARN is omitted by this approach.

[Current implementation](https://github.com/serverless/serverless/blob/2c1315666a3bd25c6c744cb810b830dd6d248160/lib/plugins/aws/package/compile/events/eventBridge/index.js#L122) added in #6397 [here](https://github.com/serverless/serverless/commit/871b04e238b19bc9c57a9b430685ad157b52b98b#diff-8996f21d004732c3332fe2aeb726f6bbR122):

```javascript
eventBusName = EventBus.split('/').pop();
```

This implementation works for custom event busses formatted as follows:

```
event-bus/<bus_name>
```

However, it is not compatible with event busses from partner sources or any ARN containing additional `/` characters such as the Segment event bus in my example:

```
event-bus/aws.partner/segment.com/XXXXXXXXXX
```

The above ARN path is converted to `event-bus/XXXXXXXXXX` which does not exist.

Similar or dependent issues:

- #6363 - PR #6397 

## Additional Data

- **_Serverless Framework Version you're using_**: v1.49.0
- **_Operating System_**: Mac OS X 10.14.6
- **_Stack Trace_**:
- **_Provider Error messages_**:
- **_Forum Post_**: https://forum.serverless.com/t/amazon-eventbridge-partner-event-sources-error/9011



Discussion:
Thanks for opening @trevorrecker :+1:

We're working on a fix for that right now...

Resolving patch:
diff --git a/lib/plugins/aws/customResources/resources/eventBridge/lib/utils.js b/lib/plugins/aws/customResources/resources/eventBridge/lib/utils.js
index 862612cb1e6..faa54fe4de1 100644
--- a/lib/plugins/aws/customResources/resources/eventBridge/lib/utils.js
+++ b/lib/plugins/aws/customResources/resources/eventBridge/lib/utils.js
@@ -2,7 +2,7 @@
 
 function getEventBusName(eventBus) {
   if (eventBus && eventBus.startsWith('arn')) {
-    return eventBus.split('/').pop();
+    return eventBus.slice(eventBus.indexOf('/') + 1);
   }
   return eventBus;
 }
diff --git a/lib/plugins/aws/package/compile/events/eventBridge/index.js b/lib/plugins/aws/package/compile/events/eventBridge/index.js
index 57e09e672c2..92336754726 100644
--- a/lib/plugins/aws/package/compile/events/eventBridge/index.js
+++ b/lib/plugins/aws/package/compile/events/eventBridge/index.js
@@ -119,7 +119,7 @@ class AwsCompileEventBridgeEvents {
               if (EventBus) {
                 let eventBusName = EventBus;
                 if (EventBus.startsWith('arn')) {
-                  eventBusName = EventBus.split('/').pop();
+                  eventBusName = EventBus.slice(EventBus.indexOf('/') + 1);
                 }
                 eventBusResource = {
                   'Fn::Join': [


Test patch:
diff --git a/lib/plugins/aws/package/compile/events/eventBridge/index.test.js b/lib/plugins/aws/package/compile/events/eventBridge/index.test.js
index 48bf115c3db..b17c12fe285 100644
--- a/lib/plugins/aws/package/compile/events/eventBridge/index.test.js
+++ b/lib/plugins/aws/package/compile/events/eventBridge/index.test.js
@@ -346,7 +346,7 @@ describe('AwsCompileEventBridgeEvents', () => {
       );
     });
 
-    it('should create the necessary resources when using an event bus arn', () => {
+    it('should create the necessary resources when using an own event bus arn', () => {
       awsCompileEventBridgeEvents.serverless.service.functions = {
         first: {
           name: 'first',
@@ -485,6 +485,134 @@ describe('AwsCompileEventBridgeEvents', () => {
       );
     });
 
+    it('should create the necessary resources when using a partner event bus arn', () => {
+      awsCompileEventBridgeEvents.serverless.service.functions = {
+        first: {
+          name: 'first',
+          events: [
+            {
+              eventBridge: {
+                eventBus: 'arn:aws:events:us-east-1:12345:event-bus/aws.partner/partner.com/12345',
+                pattern: {
+                  source: ['aws.partner/partner.com/12345'],
+                  detail: {
+                    event: ['My Event'],
+                    type: ['track'],
+                  },
+                },
+              },
+            },
+          ],
+        },
+      };
+
+      return expect(awsCompileEventBridgeEvents.compileEventBridgeEvents()).to.be.fulfilled.then(
+        () => {
+          const {
+            Resources,
+          } = awsCompileEventBridgeEvents.serverless.service.provider.compiledCloudFormationTemplate;
+
+          expect(addCustomResourceToServiceStub).to.have.been.calledOnce;
+          expect(addCustomResourceToServiceStub.args[0][1]).to.equal('eventBridge');
+          expect(addCustomResourceToServiceStub.args[0][2]).to.deep.equal([
+            {
+              Action: ['events:CreateEventBus', 'events:DeleteEventBus'],
+              Effect: 'Allow',
+              Resource: {
+                'Fn::Join': [
+                  ':',
+                  [
+                    'arn:aws:events',
+                    {
+                      Ref: 'AWS::Region',
+                    },
+                    {
+                      Ref: 'AWS::AccountId',
+                    },
+                    'event-bus/aws.partner/partner.com/12345',
+                  ],
+                ],
+              },
+            },
+            {
+              Action: [
+                'events:PutRule',
+                'events:RemoveTargets',
+                'events:PutTargets',
+                'events:DeleteRule',
+              ],
+              Effect: 'Allow',
+              Resource: {
+                'Fn::Join': [
+                  ':',
+                  [
+                    'arn:aws:events',
+                    {
+                      Ref: 'AWS::Region',
+                    },
+                    {
+                      Ref: 'AWS::AccountId',
+                    },
+                    'rule/aws.partner/partner.com/12345/first-rule-1',
+                  ],
+                ],
+              },
+            },
+            {
+              Action: ['lambda:AddPermission', 'lambda:RemovePermission'],
+              Effect: 'Allow',
+              Resource: {
+                'Fn::Join': [
+                  ':',
+                  [
+                    'arn:aws:lambda',
+                    {
+                      Ref: 'AWS::Region',
+                    },
+                    {
+                      Ref: 'AWS::AccountId',
+                    },
+                    'function',
+                    'first',
+                  ],
+                ],
+              },
+            },
+          ]);
+          expect(Resources.FirstCustomEventBridge1).to.deep.equal({
+            Type: 'Custom::EventBridge',
+            Version: 1,
+            DependsOn: [
+              'FirstLambdaFunction',
+              'CustomDashresourceDasheventDashbridgeLambdaFunction',
+            ],
+            Properties: {
+              ServiceToken: {
+                'Fn::GetAtt': ['CustomDashresourceDasheventDashbridgeLambdaFunction', 'Arn'],
+              },
+              FunctionName: 'first',
+              EventBridgeConfig: {
+                EventBus: 'arn:aws:events:us-east-1:12345:event-bus/aws.partner/partner.com/12345',
+                Input: undefined,
+                InputPath: undefined,
+                InputTransformer: undefined,
+                Pattern: {
+                  detail: {
+                    event: ['My Event'],
+                    type: ['track'],
+                  },
+
+                  source: ['aws.partner/partner.com/12345'],
+                },
+                Schedule: undefined,
+                RuleName: 'first-rule-1',
+              },
+            },
+          });
+        }
+      );
+    });
+
     it('should create the necessary resources when using an input configuration', () => {
       awsCompileEventBridgeEvents.serverless.service.functions = {
         first: {