How to run lambda function on a schedule in my localhost?-CodePudding

I want my lambda functions to be called on a schedule on my local machine so that I can easily test them before deploying. Is there any way for this?

This is my function:

sendMonthlyReport:
    Type: AWS::Serverless::Function
    Properties:
      Handler: src.monthlyReport
      Runtime: nodejs16.x
      Events:
        ScheduledEvent:
          Type: Schedule
          Properties:
            Schedule: "cron(* * * * *)"

CodePudding user response：

I would use node-cron to set a scheduler on a node file to run.

npm install --save node-cron

var cron = require('node-cron');

cron.schedule('* * * * *', () => {
    console.log('running a task every minute');
});

https://www.npmjs.com/package/node-cron

You can also check for this DigitalOcean tutorial!

CodePudding user response：

If you search for local testing before deployment of lambda functions you will probably be fed this resource by the quote-unquote "google": https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-using-debugging.html

However, there are other ways to do it.

I personally use the public docker image from aws.

Here is an example of the docker image created for a specific use case of mine.

FROM public.ecr.aws/lambda/python:3.8

RUN yum -y install tar gzip zlib freetype-devel \
    gcc \
    ghostscript \
    lcms2-devel \
    libffi-devel \
    libimagequant-devel \
    .
    enter code here
    enter code here
    and some more dependencies .... 
    && yum clean all


COPY requirements.txt ./


RUN python3.8 -m pip install -r requirements.txt
# Replace Pillow with Pillow-SIMD to take advantage of AVX2
RUN pip uninstall -y pillow && CC="cc -mavx2" pip install -U --force-reinstall pillow-simd

COPY <handler>.py ./<handler>.py

# Set the CMD to your handler
ENTRYPOINT [ "python3.8","app5.py" ]

In your case, follow instructions for node and run the docker image locally. If it works, you can then continue with aws lambda creation/update.

I see that you also have a cron job, why not use the cron job to invoke this lambda function separately and not define it in you SAML?

There are a number of ways you can invoke a lambda function based on event. For example to invoke using cli: (For aws-cliv2)

make sure you configure awscli

# !/bin/bash
export AWS_PROFILE=<your aws profile>
export AWS_REGION=<aws region>

aws lambda invoke --function-name <function name> \
--cli-binary-format raw-in-base64-out \
--log-type Tail \
--payload <your json payload > \
<output filename>

Makes it loosely coupled.

Then you can use carlo's node cronjob suggestion to invoke is as many times you like, free of charge.

CodePudding user response：

In AWS SAM, The Schedule event source type creates a AWS::Events::Rule under the hood with the lambda as the target in a full fat cloudformation template.

There is no current way to emulate this locally.