feat(events-targets): Add DLQ support for SNS target

packages/@aws-cdk/aws-events-targets/README.md

@@ -36,7 +36,7 @@ EventBridge.
 
 ## Event retry policy and using dead-letter queues
 
-The Codebuild, CodePipeline, Lambda, StepFunctions, LogGroup and SQSQueue targets support attaching a [dead letter queue and setting retry policies](https://docs.aws.amazon.com/eventbridge/latest/userguide/rule-dlq.html). See the [lambda example](#invoke-a-lambda-function).
+The Codebuild, CodePipeline, Lambda, StepFunctions, LogGroup, SQSQueue and SNSTopic targets support attaching a [dead letter queue and setting retry policies](https://docs.aws.amazon.com/eventbridge/latest/userguide/rule-dlq.html). See the [lambda example](#invoke-a-lambda-function).
 Use [escape hatches](https://docs.aws.amazon.com/cdk/latest/guide/cfn_layer.html) for the other target types.
 
 ## Invoke a Lambda function

packages/@aws-cdk/aws-events-targets/lib/sns.ts

@@ -1,11 +1,12 @@
 import * as events from '@aws-cdk/aws-events';
 import * as iam from '@aws-cdk/aws-iam';
 import * as sns from '@aws-cdk/aws-sns';
+import { addToDeadLetterQueueResourcePolicy, TargetBaseProps, bindBaseTargetConfig } from './util';
 
 /**
  * Customize the SNS Topic Event Target
  */
-export interface SnsTopicProps {
+export interface SnsTopicProps extends TargetBaseProps {
   /**
    * The message to send to the topic
    *
@@ -38,7 +39,12 @@ export class SnsTopic implements events.IRuleTarget {
     // deduplicated automatically
     this.topic.grantPublish(new iam.ServicePrincipal('events.amazonaws.com'));
 
+    if (this.props.deadLetterQueue) {
+      addToDeadLetterQueueResourcePolicy(_rule, this.props.deadLetterQueue);
+    }
+
     return {
+      ...bindBaseTargetConfig(this.props),
       arn: this.topic.topicArn,
       input: this.props.message,
       targetResource: this.topic,

packages/@aws-cdk/aws-events-targets/test/sns/integ.sns-event-rule-target.ts

@@ -22,6 +22,10 @@ const event = new events.Rule(stack, 'EveryMinute', {
 const queue = new sqs.Queue(stack, 'MyQueue');
 topic.addSubscription(new subs.SqsSubscription(queue));
 
-event.addTarget(new targets.SnsTopic(topic));
+const deadLetterQueue = new sqs.Queue(stack, 'MyDeadLetterQueue');
+
+event.addTarget(new targets.SnsTopic(topic, {
+  deadLetterQueue,
+}));
 
 app.synth();

packages/@aws-cdk/aws-events-targets/test/sns/sns-event-rule-target.integ.snapshot/aws-cdk-sns-event-target.template.json

@@ -39,6 +39,14 @@
       "Arn": {
        "Ref": "MyTopic86869434"
       },
+      "DeadLetterConfig": {
+       "Arn": {
+        "Fn::GetAtt": [
+         "MyDeadLetterQueueD997968A",
+         "Arn"
+        ]
+       }
+      },
       "Id": "Target0"
      }
     ]
@@ -98,6 +106,50 @@
      ]
     }
    }
+  },
+  "MyDeadLetterQueueD997968A": {
+   "Type": "AWS::SQS::Queue",
+   "UpdateReplacePolicy": "Delete",
+   "DeletionPolicy": "Delete"
+  },
+  "MyDeadLetterQueuePolicyCC35D52C": {
+   "Type": "AWS::SQS::QueuePolicy",
+   "Properties": {
+    "PolicyDocument": {
+     "Statement": [
+      {
+       "Action": "sqs:SendMessage",
+       "Condition": {
+        "ArnEquals": {
+         "aws:SourceArn": {
+          "Fn::GetAtt": [
+           "EveryMinute2BBCEA8F",
+           "Arn"
+          ]
+         }
+        }
+       },
+       "Effect": "Allow",
+       "Principal": {
+        "Service": "events.amazonaws.com"
+       },
+       "Resource": {
+        "Fn::GetAtt": [
+         "MyDeadLetterQueueD997968A",
+         "Arn"
+        ]
+       },
+       "Sid": "AllowEventRuleawscdksnseventtargetEveryMinuteD1FC5963"
+      }
+     ],
+     "Version": "2012-10-17"
+    },
+    "Queues": [
+     {
+      "Ref": "MyDeadLetterQueueD997968A"
+     }
+    ]
+   }
   }
  }
 }

packages/@aws-cdk/aws-events-targets/test/sns/sns-event-rule-target.integ.snapshot/cdk.out

@@ -1 +1 @@
-{"version":"17.0.0"}
+{"version":"19.0.0"}

packages/@aws-cdk/aws-events-targets/test/sns/sns-event-rule-target.integ.snapshot/integ.json

@@ -1,7 +1,7 @@
 {
-  "version": "18.0.0",
+  "version": "19.0.0",
   "testCases": {
-    "aws-events-targets/test/sns/integ.sns-event-rule-target": {
+    "sns/integ.sns-event-rule-target": {
       "stacks": [
         "aws-cdk-sns-event-target"
       ],

packages/@aws-cdk/aws-events-targets/test/sns/sns-event-rule-target.integ.snapshot/manifest.json

@@ -1,5 +1,5 @@
 {
-  "version": "17.0.0",
+  "version": "19.0.0",
   "artifacts": {
     "Tree": {
       "type": "cdk:tree",
@@ -50,6 +50,18 @@
             "type": "aws:cdk:logicalId",
             "data": "MyQueueawscdksnseventtargetMyTopicB7575CD87304D383"
           }
+        ],
+        "/aws-cdk-sns-event-target/MyDeadLetterQueue/Resource": [
+          {
+            "type": "aws:cdk:logicalId",
+            "data": "MyDeadLetterQueueD997968A"
+          }
+        ],
+        "/aws-cdk-sns-event-target/MyDeadLetterQueue/Policy/Resource": [
+          {
+            "type": "aws:cdk:logicalId",
+            "data": "MyDeadLetterQueuePolicyCC35D52C"
+          }
         ]
       },
       "displayName": "aws-cdk-sns-event-target"

packages/@aws-cdk/aws-events-targets/test/sns/sns-event-rule-target.integ.snapshot/tree.json

@@ -99,6 +99,14 @@
                         "id": "Target0",
                         "arn": {
                           "Ref": "MyTopic86869434"
+                        },
+                        "deadLetterConfig": {
+                          "arn": {
+                            "Fn::GetAtt": [
+                              "MyDeadLetterQueueD997968A",
+                              "Arn"
+                            ]
+                          }
                         }
                       }
                     ]
@@ -222,6 +230,85 @@
               "fqn": "@aws-cdk/aws-sqs.Queue",
               "version": "0.0.0"
             }
+          },
+          "MyDeadLetterQueue": {
+            "id": "MyDeadLetterQueue",
+            "path": "aws-cdk-sns-event-target/MyDeadLetterQueue",
+            "children": {
+              "Resource": {
+                "id": "Resource",
+                "path": "aws-cdk-sns-event-target/MyDeadLetterQueue/Resource",
+                "attributes": {
+                  "aws:cdk:cloudformation:type": "AWS::SQS::Queue",
+                  "aws:cdk:cloudformation:props": {}
+                },
+                "constructInfo": {
+                  "fqn": "@aws-cdk/aws-sqs.CfnQueue",
+                  "version": "0.0.0"
+                }
+              },
+              "Policy": {
+                "id": "Policy",
+                "path": "aws-cdk-sns-event-target/MyDeadLetterQueue/Policy",
+                "children": {
+                  "Resource": {
+                    "id": "Resource",
+                    "path": "aws-cdk-sns-event-target/MyDeadLetterQueue/Policy/Resource",
+                    "attributes": {
+                      "aws:cdk:cloudformation:type": "AWS::SQS::QueuePolicy",
+                      "aws:cdk:cloudformation:props": {
+                        "policyDocument": {
+                          "Statement": [
+                            {
+                              "Action": "sqs:SendMessage",
+                              "Condition": {
+                                "ArnEquals": {
+                                  "aws:SourceArn": {
+                                    "Fn::GetAtt": [
+                                      "EveryMinute2BBCEA8F",
+                                      "Arn"
+                                    ]
+                                  }
+                                }
+                              },
+                              "Effect": "Allow",
+                              "Principal": {
+                                "Service": "events.amazonaws.com"
+                              },
+                              "Resource": {
+                                "Fn::GetAtt": [
+                                  "MyDeadLetterQueueD997968A",
+                                  "Arn"
+                                ]
+                              },
+                              "Sid": "AllowEventRuleawscdksnseventtargetEveryMinuteD1FC5963"
+                            }
+                          ],
+                          "Version": "2012-10-17"
+                        },
+                        "queues": [
+                          {
+                            "Ref": "MyDeadLetterQueueD997968A"
+                          }
+                        ]
+                      }
+                    },
+                    "constructInfo": {
+                      "fqn": "@aws-cdk/aws-sqs.CfnQueuePolicy",
+                      "version": "0.0.0"
+                    }
+                  }
+                },
+                "constructInfo": {
+                  "fqn": "@aws-cdk/aws-sqs.QueuePolicy",
+                  "version": "0.0.0"
+                }
+              }
+            },
+            "constructInfo": {
+              "fqn": "@aws-cdk/aws-sqs.Queue",
+              "version": "0.0.0"
+            }
           }
         },
         "constructInfo": {

packages/@aws-cdk/aws-events-targets/test/sns/sns.test.ts

@@ -1,6 +1,7 @@
 import { Template } from '@aws-cdk/assertions';
 import * as events from '@aws-cdk/aws-events';
 import * as sns from '@aws-cdk/aws-sns';
+import * as sqs from '@aws-cdk/aws-sqs';
 import { Duration, Stack } from '@aws-cdk/core';
 import * as targets from '../../lib';
 
@@ -74,3 +75,36 @@ test('multiple uses of a topic as a target results in a single policy statement'
     Topics: [{ Ref: 'MyTopic86869434' }],
   });
 });
+
+test('dead letter queue is configured correctly', () => {
+  const stack = new Stack();
+  const topic = new sns.Topic(stack, 'MyTopic');
+  const deadLetterQueue = new sqs.Queue(stack, 'MyDeadLetterQueue');
+  const rule = new events.Rule(stack, 'MyRule', {
+    schedule: events.Schedule.rate(Duration.hours(1)),
+  });
+
+  // WHEN
+  rule.addTarget(new targets.SnsTopic(topic, {
+    deadLetterQueue,
+  }));
+
+  Template.fromStack(stack).hasResourceProperties('AWS::Events::Rule', {
+    ScheduleExpression: 'rate(1 hour)',
+    State: 'ENABLED',
+    Targets: [
+      {
+        Arn: { Ref: 'MyTopic86869434' },
+        Id: 'Target0',
+        DeadLetterConfig: {
+          Arn: {
+            'Fn::GetAtt': [
+              'MyDeadLetterQueueD997968A',
+              'Arn',
+            ],
+          },
+        },
+      },
+    ],
+  });
+});