deno-lambda VS middy

Using Deno with AWS Lambda functions requires a custom runtime. You can build your own runtime or use one that already exists. If you’re concerned about security, I suggest maintaining a copy of an existing runtime and carefully inspecting updates or creating your own runtime. For this proof of concept, I deployed the Serverless Application Repository (SAR) app for Deno into my AWS account. I used the included Lambda layer and the provided.al2 Lambda runtime to create my Deno Lambda function. I created a file called index.ts with some basic JavaScript code that makes requests to two different websites and returns the HTTP status code of the response or a caught error. I then updated the function’s configuration to reference the exported handler function.

I'm doing a simple PoC / testing with Deno using https://github.com/hayd/deno-lambda and specifically the CDK instructions.

As I had mentioned, it requires using a Lambda Layer. See: https://github.com/hayd/deno-lambda/blob/2d90756a0f18b57f16e...

Using your own image (i.e. without using the base AWS image with the layer) you'd get even worse cold start times.

Decorators and TypeScript aren't supported out of the box in Lambda (without using deno) so we'll also need a transpilation step if we go this route. Fortunately this is a mostly solved problem for AWS CDK, AWS SAM and Serverless Framework users. If you want or need to roll your own, esbuild is a great place to start and seems to be the bundler of choice for this purpose.

In addition to the stuff posted here, there's the deno-lambda project for deploying to AWS Lambda

Cloud hosting support. Deno runs fine in a container, but lambda/cloud function support is difficult on most providers. deno-lambda exists but it only applies to AWS and can't be used with all CICD tools. Deno Deploy also exists but it's pretty new.

In many cases, you will have to write the same authorization code in multiple functions. For example, you might want to check that the user is in the requested organization. You can share this code in a middleware. If you are using AWS Lambda, you can rely on middy.

Adding the is-test flag to our object metadata gave us our way of passing some kind of test context into our workload. The next step was to make the Lambda Function capable of discovering the context and then using that to control how it behaves under test. For this we used Middy.

I also decided to use the middy library to add CORS management to our lambda function. This will allow us to call our lambda function from our frontend, without having to worry about CORS.

Is there any equivalent to Node based https://middy.js.org/ for Golang?

And if your requirements were to change at a later date, it’s straightforward to swap out SSM Parameter Store with Secrets Manager there and then. Especially if you’re accessing the relevant service through a middleware layer such as Middy for javascript Lambda functions.

This function uses the Middy middleware engine to handle unhandled errors and add CORS headers in the response.

I mean I'm literally building an AWS lambda function that outputs HTML when it's called via API Gateway. So someone hits https://mydomain.com/mycoolpage, then the MyCoolPage AWS Lambda function is executed and outputs whatever.

If you're interested, I use https://middy.js.org/ as a middleware engine for my AWS lambda functions which I find helpful.

I use the open sourced serverless framework for doing deploys https://www.serverless.com/

middy for lambda-side middleware

That is it from the CDK side. Now let us create the handler and retrieve that secret. I like to use middy which describes itself as "stylish Node.js middleware engine for AWS Lambda". It offers some helpful middlewares like ssm which will help us retrieve and cache values from SSM Parameter Store. (Middy provides various other official middlewares including one for Secrets Manager.) I prefer a middleware for this because it keeps the code for retrieving the secret out of your handler which should deal with actual business logic.