fix(sqs): unable to import a FIFO queue when the queue ARN is a token (…

…aws#15976)

The fifo property of a SQS queue is determined based on the queue name. The suffix `.fifo` indicates that it is a fifo queue.
When the queue is imported from a token, the name is not known on synthesis time. Therefore, the name of the queue can't be used to initialize the queue as a FIFO queue.

In some constructs, CDK checks during synthesis if the given queue is a FIFIO queue. Because of that, an additional option is necessary to specify a FIFO queue. 

A new boolean property `fifo` is introduced which can be used to specify a FIFO queue that is imported from a token. The property is optional and is only necessary when a FIFO queue should be imported from a token.

Closes aws#12466.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/aws-sqs/lib/queue-base.ts

@@ -275,4 +275,13 @@ export interface QueueAttributes {
    * @default - None
    */
   readonly keyArn?: string;
+
+  /**
+   * Whether this queue is an Amazon SQS FIFO queue. If false, this is a standard queue.
+   *
+   * In case of a FIFO queue which is imported from a token, this value has to be explicitly set to true.
+   *
+   * @default - if fifo is not specified, the property will be determined based on the queue name (not possible for FIFO queues imported from a token)
+   */
+  readonly fifo?: boolean;
 }

packages/@aws-cdk/aws-sqs/lib/queue.ts

@@ -1,5 +1,5 @@
 import * as kms from '@aws-cdk/aws-kms';
-import { Duration, RemovalPolicy, Stack, Token } from '@aws-cdk/core';
+import { Duration, RemovalPolicy, Stack, Token, ArnFormat } from '@aws-cdk/core';
 import { Construct } from 'constructs';
 import { IQueue, QueueAttributes, QueueBase } from './queue-base';
 import { CfnQueue } from './sqs.generated';
@@ -257,7 +257,7 @@ export class Queue extends QueueBase {
    */
   public static fromQueueAttributes(scope: Construct, id: string, attrs: QueueAttributes): IQueue {
     const stack = Stack.of(scope);
-    const parsedArn = stack.parseArn(attrs.queueArn);
+    const parsedArn = stack.splitArn(attrs.queueArn, ArnFormat.NO_RESOURCE_NAME);
     const queueName = attrs.queueName || parsedArn.resource;
     const queueUrl = attrs.queueUrl || `https://sqs.${parsedArn.region}.${stack.urlSuffix}/${parsedArn.account}/${queueName}`;
 
@@ -268,9 +268,28 @@ export class Queue extends QueueBase {
       public readonly encryptionMasterKey = attrs.keyArn
         ? kms.Key.fromKeyArn(this, 'Key', attrs.keyArn)
         : undefined;
-      public readonly fifo = queueName.endsWith('.fifo') ? true : false;
+      public readonly fifo: boolean = this.determineFifo();;
 
       protected readonly autoCreatePolicy = false;
+
+      /**
+       * Determine fifo flag based on queueName and fifo attribute
+       */
+      private determineFifo(): boolean {
+        if (Token.isUnresolved(this.queueArn)) {
+          return attrs.fifo || false;
+        } else {
+          if (typeof attrs.fifo !== 'undefined') {
+            if (attrs.fifo && !queueName.endsWith('.fifo')) {
+              throw new Error("FIFO queue names must end in '.fifo'");
+            }
+            if (!attrs.fifo && queueName.endsWith('.fifo')) {
+              throw new Error("Non-FIFO queue name may not end in '.fifo'");
+            }
+          }
+          return queueName.endsWith('.fifo') ? true : false;
+        }
+      }
     }
 
     return new Import(scope, id);

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

@@ -1,7 +1,7 @@
 import { expect, haveResource, ResourcePart } from '@aws-cdk/assert-internal';
 import * as iam from '@aws-cdk/aws-iam';
 import * as kms from '@aws-cdk/aws-kms';
-import { CfnParameter, Duration, Stack, App } from '@aws-cdk/core';
+import { CfnParameter, Duration, Stack, App, Token } from '@aws-cdk/core';
 import { Test } from 'nodeunit';
 import * as sqs from '../lib';
 
@@ -191,6 +191,87 @@ export = {
       test.done();
     },
 
+    'import queueArn from token, fifo and standard queues can be defined'(test: Test) {
+      // GIVEN
+      const stack = new Stack();
+
+      // WHEN
+      const stdQueue1 = sqs.Queue.fromQueueAttributes(stack, 'StdQueue1', {
+        queueArn: Token.asString({ Ref: 'ARN' }),
+      });
+      const stdQueue2 = sqs.Queue.fromQueueAttributes(stack, 'StdQueue2', {
+        queueArn: Token.asString({ Ref: 'ARN' }),
+        fifo: false,
+      });
+      const fifoQueue = sqs.Queue.fromQueueAttributes(stack, 'FifoQueue', {
+        queueArn: Token.asString({ Ref: 'ARN' }),
+        fifo: true,
+      });
+
+      // THEN
+      test.deepEqual(stdQueue1.fifo, false);
+      test.deepEqual(stdQueue2.fifo, false);
+      test.deepEqual(fifoQueue.fifo, true);
+      test.done();
+    },
+
+    'import queueArn from token, check attributes'(test: Test) {
+      // GIVEN
+      const stack = new Stack();
+
+      // WHEN
+      const stdQueue1 = sqs.Queue.fromQueueArn(stack, 'StdQueue', Token.asString({ Ref: 'ARN' }));
+
+      // THEN
+      test.deepEqual(stack.resolve(stdQueue1.queueArn), {
+        Ref: 'ARN',
+      });
+      test.deepEqual(stack.resolve(stdQueue1.queueName), {
+        'Fn::Select': [5, { 'Fn::Split': [':', { Ref: 'ARN' }] }],
+      });
+      test.deepEqual(stack.resolve(stdQueue1.queueUrl), {
+        'Fn::Join':
+          ['',
+            ['https://sqs.',
+              { 'Fn::Select': [3, { 'Fn::Split': [':', { Ref: 'ARN' }] }] },
+              '.',
+              { Ref: 'AWS::URLSuffix' },
+              '/',
+              { 'Fn::Select': [4, { 'Fn::Split': [':', { Ref: 'ARN' }] }] },
+              '/',
+              { 'Fn::Select': [5, { 'Fn::Split': [':', { Ref: 'ARN' }] }] }]],
+      });
+      test.deepEqual(stdQueue1.fifo, false);
+      test.done();
+    },
+
+    'fails if fifo flag is set for non fifo queue name'(test: Test) {
+      // GIVEN
+      const app = new App();
+      const stack = new Stack(app, 'my-stack');
+
+      // THEN
+      test.throws(() => sqs.Queue.fromQueueAttributes(stack, 'ImportedStdQueue', {
+        queueArn: 'arn:aws:sqs:us-west-2:123456789012:queue1',
+        fifo: true,
+      }), /FIFO queue names must end in '.fifo'/);
+      test.done();
+    },
+
+
+    'fails if fifo flag is false for fifo queue name'(test: Test) {
+      // GIVEN
+      const app = new App();
+      const stack = new Stack(app, 'my-stack');
+
+      // THEN
+      test.throws(() => sqs.Queue.fromQueueAttributes(stack, 'ImportedFifoQueue', {
+        queueArn: 'arn:aws:sqs:us-west-2:123456789012:queue1.fifo',
+        fifo: false,
+      }), /Non-FIFO queue name may not end in '.fifo'/);
+      test.done();
+    },
+
     'importing works correctly for cross region queue'(test: Test) {
       // GIVEN
       const stack = new Stack(undefined, 'Stack', { env: { region: 'us-east-1' } });