We are exposing a AWS Api Gateway which needs to act as proxy and push body as message to AWS SQS. Our API gateway body can be array of object which we need to parse and send each object to SQS as separate message. Is there any way to achieve this without using Lambda ?
To answer your question, for something as simple as parsing a message and posting to SQS, I don't believe you need Lambda, no. Lambdas are designed for serverless-architecture. That is, when you don't have a server and you still want to run code. In this case, you do have a server behind your API Gateway, so you don't need Lambda (unless you want fancy branching error handling). You can use your API Gateway directly, yep. Here's a code review I found:
https://dzone.com/articles/creating-aws-service-proxy-for-amazon-sqs
Related
I have created a micro service architecture which flows as follows:
Api call -> Api gateway -> Eventbridge -> SNS -> Lambda
The reason for this is to use SNS instead of SQS to decouple applications for true serverless compute without the need for lambda to continuously poll sqs, pub sub over push poll.
The trouble is that although the execution is fine and the lambdas run as expected the return received by the user or app is the eventbridge response. I can’t find any docs on how eventbridge handles responses for http requests through API gateway.
Does anyone have any ideas or docs to push me in the right direction.
Thanks!
In your setup it's not possible to have the Lambda response proxied back to the api request initiator, as your client is very much decoupled of the actual request processing.
Almost identical issue was experienced here
You need to rethink the process as a whole:
what operation you want to complete via the API request?
does the processing of the request really need to be asynchronous (= does it take long time to complete?)
can you handle the request with a Lambda function, delegate to sns from there and finally generate desired response back to the client?
So as it turns out the answer is yes and no for anyone coming across this in the future.
With the current setup another database is required and the responses can be inserted into it with a transaction ID. This transaction ID can be generated by the client during the request so a subsequent call to find the response in the table can be made.
Alternatively Websocket or GraphQL api’s or would allow for asynchronous invocation if really depends on your use case and accepted complexity.
Thanks for everyone’s inputs!
Since there is aditional costs for using HTTP and REST apis on AWS lambda, i would like to know if i could make AWS Lambda receive gets and posts without the need of these HTTP API services.
In this example it seems to be possible:
https://github.com/serverless/examples/tree/master/aws-node-simple-http-endpoint
You will need to use the API Gateway to expose your lambda. Your example is actually using an API Gateway, because the endpoint is execute-api.us-east-1.amazonaws.com and that is the Amazon API Gateway Data Plane.
Just to be clear; if you need to expose the Lambda externally you need to use the API Gateway. If the Lambda needs to be invoked internally then you don't need the API GW.
Best regards
Lambda also exposes a client API in all languages. Therefore, you can invoke a Lambda function by using the client API (not use API Gateway if you prefer). For example, assume you want the ability to invoke a Lambda function from a Java web app. In this situation, you can use the LambdaClient object to do so. You can find an example here:
https://github.com/awsdocs/aws-doc-sdk-examples/blob/master/javav2/example_code/lambda/src/main/java/com/example/lambda/LambdaInvoke.java
I am using AWS API Gateway with HTTP API which invokes a lambda function. However HTTP API doesn't include USAGE feature. According to my requirement I need to create a usage for a client depending on the status code of the response sent back by the lambda. Since I cant access the response sent by lambda in API Gateway, I am looking for an custom solution. I am planing to use STEP function.
For example:
Instead of API Gateway directly invoking a lambda function it can call a STEP function where I can execute LambdaA. next it would trigger LambdaB with response from LambdaA as input to LambdaB in a sequential manner. I don't know If this is the right approach
I would like to know what is best way of solving this problem...thanks in advance
Is it possible to make some kind of HTTP request that will trigger Lambda and allow it to build a response for the request?
Is it possible for Lambda to access CloudFront cache directly or somehow get the data it needs. I guess it can be done making HTTP requests to CloudFront, but maybe there is more direct way to do that, no?
Or all this stuff I'm asking here is a peace of **** and I better go and buy a new server or optimize my code (actually, i would like to, but manager wants CloudFront + Lambda, so I'm trying to figure out if that is possible, but the docs don't give me an answer. Am I blind maybe?)
You can expose your lambda function via an API gateway. Then your lambda function can just run code that will access other services/resources (CloundFront, SNS, SQS, etc). Use the AWS SDK to access these services.
See Amazon API Gateway documentation: http://docs.aws.amazon.com/apigateway/latest/developerguide/getting-started.html
I'm using API Gateway-to-Lambda for a few micro-services but in at least one case the service will take 20-30 seconds to complete so in cases like this I'd like to pass back an immediate response to the client, something like:
status: 200
message: {
progressId: 1234
}
and then allow the Lambda Function to continue on (and periodically updating the "processId" somewhere that is accessible to a client. The problem is that if you call context.succeed(), context.fail(), or context.done() that apparently stops the lambda function from further execution and yet it's the only way I know to flush the stdout buffer back to the API Gateway.
This has led me to a second approach which I haven't yet try to tackle (and for simplicity sake would love to avoid) which involves API Gateway calling a "Responder" Lambda function that then asynchronously fires off the Microservice and then immediately responds to the API Gateway.
I've tried to illustrate these two options in sketch format below. I'd love to hear how anyone's been able to solve this problem.
Currently API Gateway requires that the AWS Lambda integration is synchronous. If you desire asynchronous invocation of your Lambda function, you have 2 options:
Invoking the Lambda asynchrously, either with an AWS integration calling InvokeAsync on Lambda, or using an intermediate service such as SNS or Kinesis to trigger the Lambda function.
You're #2 diagram, using a synchronous Lambda invoke to initiate the asynchronous invoke.
As of Apr/2016 is it is possible to create async Lambda execution through API Gateway by using AWS Service Proxy. See http://docs.aws.amazon.com/apigateway/latest/developerguide/integrating-api-with-aws-services-lambda.html
You can send the X-Amz-Invocation-Type header, it supports async calls through the Event value
You can optionally request asynchronous execution by specifying Event as the InvocationType
http://docs.aws.amazon.com/lambda/latest/dg/API_Invoke.html#API_Invoke_RequestSyntax
Also, if you can't send it via your micro-service, you can configure this header to be passed by default through the Method Execution -> Integration Request -> HTTP Headers in your API Gateway Resource
This worked for me on a micro-service -> API Gateway -> Lambda scenario, like the mentioned on the question.