Serverless invoke local does nothing

Question

I'm trying to run locally a node lambda to debug it. I am using Serverless and this launch config in vsCode

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "node",
      "request": "launch",
      "name": "Launch Program",
      "program": "${workspaceRoot}/node_modules/.bin/sls",
      "args": [
        "invoke",
        "local",
        "--function",
        "hello",
        "--data",
        "hello world"
      ]
    }
  ]
}

My export.handler looks like this:

module.exports.handler = (event, context, callback) => {
  if (event.triggerSource === CONSTANTS.TRIGGER_SOURCE) {
    console.log("event = " + JSON.stringify(event));
    const uri = process.env.SCT_URL_BASE;
    const country = process.env.SCT_COUNTRY;

    const username = 
event.request.userAttributes[CONSTANTS.USER_ATTRIBUTES];
    const codeP = event.request.codeParameter;
    console.log("URI = " + url);
    console.log("Code:" + codeP);

    getUrlData(uri, country, username, codeP);
  } else {
    context.done(null, event);
  }
};

When I run de debug mode it does nothing. Serverless does not throw any error, I just can not reach inside the function.

Also, there is another thing I can not understand. In serverless documentation it said:

--function or -f The name of the function in your service that you want to invoke locally. Required.

I don't know what they are refering in this, if a function that we call to run the lambda or the function that it is called when the lambda is called. In this case, the function that I am exporting is "handler" but it doesn't work either.

Thanks in advance.

What caused this for me was running the sls command from outside of the Serverless service directory. Make sure you you're in the correct directory. — Harvinder

Jorge Belano Murphy Jorge Belano Murphy · Accepted Answer · 2018-05-30T07:24:26

I have used this approach and it works for me:

https://standardofnorms.wordpress.com/2017/12/03/locally-debugging-aws-lambdas-written-in-node-js/

The bad thing is that I would like to use serverless and not lambda-local package due to the greater community of serverless. Lambda-local works like charm though, so I send a big hug to its creator from here.

Answers to the first question are still very welcome.

EDIT: Ok, I figured this out.

Results that Serverless, as framework, uses a serverless.yml file when we need to add some configuration. There, I had to create the function I am going to run with the serverless command and then point it to the file where I have my handler. This is my serverles.yml right now:

service: serverless-simple

frameworkVersion: ">=1.1.0 <2.0.0"

provider:
  name: aws
  runtime: nodejs4.3

functions:
  lambdaHandler:
    handler: src/customMessageLambda.handler
    events:
      - http:
          path: ping

Sure I have to research a little more on this file but I have solved my issue.

Hope this helps someone, sometime.

Serverless invoke local does nothing

2 Answers