Aws lambda how to use/mention aws api gateway in serverless.yml - node.js

Question

I'm learning aws lambda (creating some rest apis, apply rate limiting). I have read some examples from aws and they said that we need to create/use aws API gateway to route to lambda function (UI based)
But I also found in the internet this serverless.yml. No need to use UI anymore
functions:
simple:
handler: handler.simple
events:
- httpApi: 'PATCH /elo'
extended:
handler: handler.extended
events:
- httpApi:
method: POST
path: /post/just
You guys can see there is no where that mention about api gateway. So my questions are:
If I use configuration like that, how can I know whether it is using API gateway or not? If not, how can I specify it to use API gateway?
Is Lambda-Proxy or Lambda Integration used in this case (read more here)? How can I specify it to use Lambda Integration?
Is aws API gateway suitable for rate limiting? Like allow only 1000 request per user (bearer token) per 120 minutes.
Since I'm still waiting for aws account, I have no environment to test. Any help would be appreciated

Answer 1

First, let's establish that there are two different types of endpoints in API Gateway: REST APIs and HTTPS APIs. These offer different features and customization. For example, REST APIs offer client-level throttling, whereas HTTPS APIs do not. You can see more information about both versions here.
This configuration would create a new HTTPS API gateway endpoint. When you specify that the event triggering the lambda is a post to that specific path, your deployment will create a new endpoint with API gateway to enable that automatically.
The serverless framework allows you to specify whether or not you want to use a REST API or an HTTPS API. The syntax above is for the HTTPS API -- also referred to in serverless' documentation as v2, which by default only supports lambda-proxy. You can opt to use a REST API which can be configured to use either, as you can see reading through the documentation here
You can enable throttling on REST APIs as shown in the (documentation)3:
service: my-service
provider:
name: aws
apiGateway:
apiKeys:
- myFirstKey
- ${opt:stage}-myFirstKey
# you can hide it in a serverless variable
- ${env:MY_API_KEY}
- name: myThirdKey
value: myThirdKeyValue
# let cloudformation name the key (recommended when setting api key value)
- value: myFourthKeyValue
description: Api key description # Optional
customerId: A string that will be set as the customerID for the key # Optional
usagePlan:
quota:
limit: 5000
offset: 2
period: MONTH
throttle:
burstLimit: 200
rateLimit: 100
Then in your function definition:
functions:
hello:
events:
- http:
path: user/create
method: get
private: true