feat(@aws-cdk/aws-events-triggers): introducing sqs target support in event rule

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

@@ -1,5 +1,6 @@
 export * from './codepipeline';
 export * from './sns';
+export * from './sqs';
 export * from './codebuild';
 export * from './lambda';
 export * from './ecs-task-properties';

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

@@ -0,0 +1,47 @@
+import events = require('@aws-cdk/aws-events');
+import iam = require('@aws-cdk/aws-iam');
+import sqs = require('@aws-cdk/aws-sqs');
+
+/**
+ * Customize the SQS Queue Event Target
+ */
+export interface SqsQueueProps {
+  /**
+   * The message to send to the queue
+   *
+   * @default the entire CloudWatch event
+   */
+  readonly message?: events.RuleTargetInput;
+}
+
+/**
+ * Use an SQS Queue as a target for AWS CloudWatch event rules.
+ *
+ * @example
+ *
+ *    // publish to an SQS queue every time code is committed
+ *    // to a CodeCommit repository
+ *    repository.onCommit(new targets.SqsQueue(queue));
+ *
+ */
+export class SqsQueue implements events.IRuleTarget {
+  constructor(public readonly queue: sqs.IQueue, private readonly props: SqsQueueProps = {}) {
+  }
+
+  /**
+   * Returns a RuleTarget that can be used to trigger this SQS queue as a
+   * result from a CloudWatch event.
+   *
+   * @see https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/resource-based-policies-cwe.html#sqs-permissions
+   */
+  public bind(_rule: events.IRule): events.RuleTargetProperties {
+    // deduplicated automatically
+    this.queue.grantSendMessages(new iam.ServicePrincipal('events.amazonaws.com'));
+
+    return {
+      id: this.queue.node.id,
+      arn: this.queue.queueArn,
+      input: this.props.message,
+    };
+  }
+}

packages/@aws-cdk/aws-events-targets/test/sqs/integ.sqs-event-rule-target.expected.json

@@ -0,0 +1,68 @@
+{
+  "Resources": {
+    "EveryMinute2BBCEA8F": {
+      "Type": "AWS::Events::Rule",
+      "Properties": {
+        "ScheduleExpression": "rate(1 minute)",
+        "State": "ENABLED",
+        "Targets": [
+          {
+            "Arn": {
+              "Fn::GetAtt": [
+                "MyQueueE6CA6235",
+                "Arn"
+              ]
+            },
+            "Id": "MyQueue"
+          }
+        ]
+      }
+    },
+    "MyQueueE6CA6235": {
+      "Type": "AWS::SQS::Queue"
+    },
+    "MyQueuePolicy6BBEDDAC": {
+      "Type": "AWS::SQS::QueuePolicy",
+      "Properties": {
+        "PolicyDocument": {
+          "Statement": [
+            {
+              "Action": [
+                "sqs:SendMessage",
+                "sqs:SendMessageBatch",
+                "sqs:GetQueueAttributes",
+                "sqs:GetQueueUrl"
+              ],
+              "Effect": "Allow",
+              "Principal": {
+                "Service": {
+                  "Fn::Join": [
+                    "",
+                    [
+                      "events.",
+                      {
+                        "Ref": "AWS::URLSuffix"
+                      }
+                    ]
+                  ]
+                }
+              },
+              "Resource": {
+                "Fn::GetAtt": [
+                  "MyQueueE6CA6235",
+                  "Arn"
+                ]
+              }
+            }
+          ],
+          "Version": "2012-10-17"
+        },
+        "Queues": [
+          {
+            "Ref": "MyQueueE6CA6235"
+          }
+        ]
+      }
+    }
+  }
+}

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

@@ -0,0 +1,22 @@
+import events = require('@aws-cdk/aws-events');
+import sqs = require('@aws-cdk/aws-sqs');
+import cdk = require('@aws-cdk/cdk');
+import targets = require('../../lib');
+
+// ---------------------------------
+// Define a rule that triggers an SNS topic every 1min.
+// Connect the topic with a queue. This means that the queue should have
+// a message sent to it every minute.
+
+const app = new cdk.App();
+
+const stack = new cdk.Stack(app, 'aws-cdk-sqs-event-target');
+
+const event = new events.Rule(stack, 'EveryMinute', {
+  scheduleExpression: 'rate(1 minute)',
+});
+
+const queue = new sqs.Queue(stack, 'MyQueue');
+event.addTarget(new targets.SqsQueue(queue));
+
+app.run();

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

@@ -0,0 +1,84 @@
+import { expect, haveResource } from '@aws-cdk/assert';
+import events = require('@aws-cdk/aws-events');
+import sqs = require('@aws-cdk/aws-sqs');
+import { Stack } from '@aws-cdk/cdk';
+import targets = require('../../lib');
+
+test('sqs queue as an event rule target', () => {
+  // GIVEN
+  const stack = new Stack();
+  const queue = new sqs.Queue(stack, 'MyQueue');
+  const rule = new events.Rule(stack, 'MyRule', {
+    scheduleExpression: 'rate(1 hour)',
+  });
+
+  // WHEN
+  rule.addTarget(new targets.SqsQueue(queue));
+
+  // THEN
+  expect(stack).to(haveResource('AWS::SQS::QueuePolicy', {
+    PolicyDocument: {
+      Statement: [
+        {
+          Action: [
+            "sqs:SendMessage",
+            "sqs:SendMessageBatch",
+            "sqs:GetQueueAttributes",
+            "sqs:GetQueueUrl"
+          ],
+          Effect: "Allow",
+          Principal: {
+            Service: { "Fn::Join": ["", ["events.", { Ref: "AWS::URLSuffix" }]] },
+          },
+          Resource: { "Fn::GetAtt": ["MyQueueE6CA6235", "Arn"] },
+        }
+      ],
+      Version: "2012-10-17"
+    },
+    Queues: [{ Ref: "MyQueueE6CA6235" }]
+  }));
+
+  expect(stack).to(haveResource('AWS::Events::Rule', {
+    ScheduleExpression: "rate(1 hour)",
+    State: "ENABLED",
+    Targets: [
+      {
+        Arn: { "Fn::GetAtt": ["MyQueueE6CA6235", "Arn"] },
+        Id: "MyQueue"
+      }
+    ]
+  }));
+});
+
+test('multiple uses of a queue as a target results in a single policy statement', () => {
+  // GIVEN
+  const stack = new Stack();
+  const queue = new sqs.Queue(stack, 'MyQueue');
+
+  // WHEN
+  for (let i = 0; i < 5; ++i) {
+    const rule = new events.Rule(stack, `Rule${i}`, { scheduleExpression: 'rate(1 hour)' });
+    rule.addTarget(new targets.SqsQueue(queue));
+  }
+
+  // THEN
+  expect(stack).to(haveResource('AWS::SQS::QueuePolicy', {
+    PolicyDocument: {
+      Statement: [
+        {
+          Action: [
+            "sqs:SendMessage",
+            "sqs:SendMessageBatch",
+            "sqs:GetQueueAttributes",
+            "sqs:GetQueueUrl"
+          ],
+          Effect: "Allow",
+          Principal: { Service: { "Fn::Join": ["", ["events.", { Ref: "AWS::URLSuffix" }]] } },
+          Resource: { "Fn::GetAtt": ["MyQueueE6CA6235", "Arn"] },
+        }
+      ],
+      Version: "2012-10-17"
+    },
+    Queues: [{ Ref: "MyQueueE6CA6235" }]
+  }));
+});