Emulating Amazon SQS during development

I'm quite interested in beginning some development using Amazon SQS, perhaps SimpleDB too, my question is this, are there any open source solutions that mimic the functionality, just for the purposes of development. I've already encountered the Eucalyptus project (<http://open.eucalyptus.com>;) for creating an EC-esque cloud.

I've not had any success with google, I suspect it's because the cost of entry is so inexpensive, but still, does anyone know of anything like this?

For SQS I wrote ElasticMQ, which you can run either embedded (it's written in Scala, so runs on the JVM) or stand-alone. It has both persistent and in-memory modes, the first being good for dev, second for testing.

Some of the Amazon SDKs have "mock" mode, which is:

> The mock service is an alternate way > to use the sample code. The service > doesn't call AWS, but instead returns > a set response that you can modify to > suit your needs (the XML response > files are in the Mock directory). The > mock service makes it easy for you to > test how your application handles > different responses.

For SQS, it appears the Perl and PHP SDKs have mock mode. I know that the .NET SDK for Amazon RDS also has the mock mode.

The Java SDK doesn't contain mock implementations:

> The client mock implementations have been removed. Instead, developers > are encouraged to use more flexible and full featured mock libraries, > such as EasyMock, jMock

If the SDK you will be using doesn't have the mock mode available, you could probably create your own similar type of thing which returns the preconfigured responses instead of actually hitting up the service.

See here for more info

If you need a test double for more than just SQS, you can try LocalStack.

To simulate SQS, it internally uses ElasticMQ mentioned by adamw.

You can start LocalStack via Docker, for example, and it will start the following services:

• API Gateway at http://localhost:4567
• Kinesis at http://localhost:4568
• DynamoDB at http://localhost:4569
• DynamoDB Streams at http://localhost:4570
• Elasticsearch at http://localhost:4571
• S3 at http://localhost:4572
• Firehose at http://localhost:4573
• Lambda at http://localhost:4574
• SNS at http://localhost:4575
• SQS at http://localhost:4576
• Redshift at http://localhost:4577
• ES (Elasticsearch Service) at http://localhost:4578
• SES at http://localhost:4579
• Route53 at http://localhost:4580
• CloudFormation at http://localhost:4581
• CloudWatch at http://localhost:4582
• SSM at http://localhost:4583

GoAws - https://github.com/p4tin/goaws - was just released as beta. (disclaimer - I am the developer).

Regarding the Java SDK, it does no longer contain mock implementations:

> The client mock implementations have been removed. Instead, developers > are encouraged to use more flexible and full featured mock libraries, > such as EasyMock, jMock

If you are in .NET or Mono you can try Stratosphere. It has local implementations that mimic SimpleDB, SQS and S3. For SimpleDB mock implementation it uses SQLite, for SQS and S3 it stores messages/objects in file system.

if you need to simulate SNS as well as SQS you can check out: Yopa