As others have noted, ECS or Fargate would be more appropriate for cases that fall outside the Lambda event model.
[1] https://docs.aws.amazon.com/lambda/latest/dg/runtimes-api.ht...
So in other words, you can’t run any container.
Again, the entire point of containers is portability across execution environments. If I have to build special containers specifically for Lambda because they require these special runtimes, that defeats the entire point.
> You can't run a random container and expect Lambda to know how it should communicate with the world.
Google Cloud Run, which everyone keeps comparing this with, works exactly like that. Upload any random container, tell it which port to open, and bam... running application. You don’t have to mess around with adding any “Cloud Run runtimes” or modifying your code to add special “Cloud Run handlers”. Because that would be silly.
I had exactly the same thought you're expressing here when I first built a Lambda to serve as a HTTP API manually after previously using Azure a tiny bit. In Azure you write their equivalent function and one of the built-in trigger options is HTTP, you enable that and immediately get a URL. Lambdas are quite close to that now I think if you're using the console UI, but you used to have to go through API gateway and set everything up manually.
But the point is that Lambdas aren't HTTP APIs that listen on a single port. They receive events that can be proxied HTTP requests via API Gateway, or messages on queues, or completely arbitrary invocations from step functions, or notifications that look nothing like HTTP from S3 buckets. I'd like the Cloud Run model when my lambda is acting like an HTTP API, but I don't think it'd be much fun to have to treat every AWS event as a full HTTP request for everything else.
I'm not very familiar with Google Cloud, but I think their equivalent is Cloud Functions which looks very similar to Lambda's pre-container model: https://cloud.google.com/functions/docs/writing
Do Google represent a JSON body HTTP event in a clean way? In AWS when a lambda is working as one, it receives the body as a string in the JSON representing the request, which you have to JSON decode. Again because not everything a Lambda can act on is JSON and your API doesn't have to be, what else can it really do I guess. But it does make it a bit horrible to generate that data to test with - we actually have a small script we use locally to convert a nicely formatted JSON file with test data into their HTTP-request-as-json format because it's so annoying to work with a large encoded JSON body. It's a small thing, but it means when you switch to working with a plain AWS event it's one less thing to think about. And I guess even if you're in HTTP-Request-Land and everything is nice JSON, it's still all going to be custom between services from there on by necessity.
> Google Cloud Run, which everyone keeps comparing this with, works exactly like that.
Everyone does keep comparing this to GCR, wrongly. Not just because Lambda is not "bring any container" whereas GCR is, but more importantly because GCR and Lambda have very different operational models. GCR is a serverless platform for hosting web servers. Lambda is a serverless platform for event handling. The latter is a super-set of the former and thus requires more specific tools.
Yes, theoretically there could be a setup whereby you expose a port, and some lambda intermediary translates the invocation payload to an HTTP message your container can read. But I am endlessly fascinated why anyone would want that. I laugh a bit on how we've hit peak AWS where people here are legitimately asking for an HTTP request to hit an ALB, the ALB translates it into a lambda payload object, then a lambda component re-translates that payload back into an HTTP request, so your application can translate it into an object. Do you understand how insane that is?
The only tactile advantage lambda has over fargate is scale-to-zero. I think saving $7 per month is a pretty bad trade-off for the insane performance overhead and complexity a true docker-in-lambda solution would necessitate, and thus be unattractive to most consumers.