serverless-offline VS docker-lambda

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.

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

Step 2: Push a container from your local machine to ECR. Currently, I use sample python lambda docker from https://github.com/lambci/docker-lambda.git

You can see the following projects for some examples of using this plugin to build a layer. They all leverage Docker and the docker-lambda images to compile for AWS’s Lambda environment on any operating system:

I end up using Lambda a lot so lambci is very useful for local testing: https://github.com/lambci/docker-lambda

There are kind souls in this world who created this: https://github.com/lambci/docker-lambda

If all you need is the ability to run a lambda function's code locally you might interested in docker-lambda[1]. I haven't really used localstack or SAM but a couple of years ago when we needed to run some lambda functions locally for development docker-lambda worked well enough.

[1] https://github.com/lambci/docker-lambda

Docker Lambda — Docker Lambda is a tool which tries to replicate the AWS Lambda environment as closely as possible, but within a Docker container. Docker Lambda has support for most of the AWS Lambda run times.

Want to emulate AWS environments? Try docker-lambda.