serverless-offline VS Moto

Using local emulators like sam local, serverless-offline, localstack, etc.

Hi, I'm the creator of serverless-offline (https://github.com/dherault/serverless-offline), a NPM package for local serveless development on AWS.

I'm building a cool product and intend to launch Q1 2023. To gain traction from my target customers, I plan to place a discrete ad at the launch of every serverless-offline instance.

Does it seem like an ok move to you? Or is it something that repels you?

Best,

As the creator of serverless-offline, I am well placed to tell you that this is the time-effective solution. Plus, it costs way less than other solutions at smaller scales. But, again, going Kubernetes or otherwise will be a problem for the future.

https://github.com/dherault/serverless-offline https://github.com/lambci/docker-lambda

What if I didn’t need to push code to AWS every time I wanted to test something? All heroes don’t wear capes. Like a knight in shining armor, Serverless Offline comes barging in to save the day! At least now I can test all my code locally before pushing it to AWS. That’s a relief.

With classic Express servers, you can use a simple node script to get the server up and running to test locally. Serverless wants to be run in the AWS ecosystem making it. Lucky for us, David Hérault has built and continues to maintain serverless-offline allowing us to emulate our functions locally before we deploy.

With the serverless offline plugin you can speed up local dev is by emulating AWS lambda and API Gateway locally when developing your Serverless project.

Those mocks are by definition not real services so there are some behavior differences between the local environment and the cloud provider. For example, AWS API Gateway emulated by serverless-offline doesn't handle VTL locally the same as AWS does.

serverless-offline (https://github.com/dherault/serverless-offline) is a great tool to use for local development of serverless applications.

It's not a complete mirror image of what you get but it's close enough in my experience.

> OpenMoto

I dunno if you're trying to play on "hashimoto" but https://github.com/getmoto/moto#readme would be a prime name collision for any such "OpenMoto" name

But yes, please, to adopting Vault. I don't have a horse in the race about Consul but my suspicion is such an effort would only be worthwhile if trying to adopt Nomad, too, which I gravely doubt

Unfortunately I do not believe AWS provides any "test" gateways. I do know there are mock AWS servers you can run on your own. The one I use is called Moto. It does not cover everything (unfortunately it's the most comprehensive out there AFAIK), but it's decent enough to test most standard calls via the sdk. I'm not sure if it covers authorization though...we tend to use security roles on tasks for authorization.

If using Python use Moto to mock AWS Services

You can use a library such as moto https://github.com/getmoto/moto

The Pythonic motto library mocks AWS services, removing the need to deploy your application or pay for API calls against AWS services. Other programming languages have their motto implementation.

Has anyone managed to configure moto (https://docs.getmoto.org/en/latest/) in a docker container in the similar way LocalStack does?

As for mocking, you can take a look at the moto library for mocking the AWS SDK, or for more simple cases even just use a `unittest.Mock/MagicMock` object. If you're having trouble trying to use the mocks in your code, it's a good sign your code is too highly coupled and it'd pay to re-factor, for example using dependency injection, design patterns like adapter/facade etc. (but don't over-do it)

To add on to the integration tests point, for mocking out your AWS resources you should check out moto if you don't want run your test against real AWS resources as they may cost you and is usually slower.