Invoke AWS lambda function from container without request body-CodePudding

I have an AWS lambda function (nodejs) that will return a pdf with Content-Type: "application/pdf".

I learned how to prepare it for deployment in a container image, and the documentation says i can invoke it locally with curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}',
where the -XPOST seems unnecessary as the function will just read the request body provided by --data/-d even if it's from the default -XGET.

Either way, at this point i'm not processing any request body yet, and i could as well not even intend to, but if i omit the request body (or provide an invalid json like -d "abc"), the Runtime Interface Client fails before even invoking my function with this error:

 {"errorType":"SyntaxError"
 ,"errorMessage":"Unexpected end of JSON input"
 ,"trace":
["SyntaxError: Unexpected end of JSON input"
,"    at JSON.parse (<anonymous>)"
,"    at Runtime.handleOnceNonStreaming (file:///var/runtime/index.mjs:1089:42)"
]}

(or Unexpected token a in JSON at position 0, for the -d "abc")

If i could access the local function url from browser, i could immediately see the returned pdf result, but there's no way to provide a dummy request body there. How do I allow the lambda interface to accept simple get requests without a body?

CodePudding user response：

curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}'

A POST request here doesn't mean your Lambda is required to process a POST request. Because here you're invoking the aws-lambda-ric, not the Lambda itself. The runtime interface client is designed in a way to accept a POST request, and then, it invokes your local Lambda.

Inside -d '{}' you then provide the exact payload your Lambda is expected to receive as the event argument.

If your Lambda designed to work with API GW trigger, and accept only GET requests, then it will look smth like:

curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{"resource":"/","path":"/","httpMethod":"GET","requestContext":{"resourcePath":"/","httpMethod":"GET","path":"/Prod/"},"headers":{"accept":"text/html,application/xhtml xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9","accept-encoding":"gzip, deflate, br","Host":"70ixmpl4fl.execute-api.us-east-2.amazonaws.com","User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36","X-Amzn-Trace-Id":"Root=1-5e66d96f-7491f09xmpl79d18acf3d050"},"multiValueHeaders":{"accept":["text/html,application/xhtml xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9"],"accept-encoding":["gzip, deflate, br"]},"queryStringParameters":null,"multiValueQueryStringParameters":null,"pathParameters":null,"stageVariables":null,"body":null,"isBase64Encoded":false}'

Sample GET request payload for the event argument is taken from documentation.

So you mock a GET request by modifying what you pass inside -d '{}' (see where the example command has {"resource":"/","path":"/","httpMethod":"GET").

Not by changing the HTTP method of aws-lambda-ric.