Scheduled events for one lambda cause permission policy size to exceed limit (20480 MB) about serverless

[joshverma]

Have you found a solution for this?

[locerito]

Any solutions or workaround?

[charlotteveitner]

Any solutions or workaround?

@locerito I ended up splitting the events and deploying two seperate lambda functions with half of the events in each. Obviously not the cleanest approach but at least I am still able to deploy 👍🏽

[locerito]

Any solutions or workaround?

@locerito I ended up splitting the events and deploying two seperate lambda functions with half of the events in each. Obviously not the cleanest approach but at least I am still able to deploy 👍🏽

@charlotteveitner, Thanks for the answer, I will investigate a little more but since there is no clean way to do it, for now I apply another approach.
I'll tell you what I've done in case you're interested.

I apply a common permission to all event bridge rules with a wildcard.

resources:
  Resources:
    PermissionToCallEventRouterController:
      Type: "AWS::Lambda::Permission"
      Properties: 
        Action: lambda:InvokeFunction
        FunctionName: 
          Ref: EventUnderscorerouterUnderscorecontrollerLambdaFunction
        Principal: "events.amazonaws.com"
        SourceArn: "arn:aws:events:${self:provider.region}:${file(config.${opt:stage, 'dev'}.json):account}:rule/ocr_*"

To deploy, I run a package command, then I delete all EventBridgeLambdaPermission cloudformation resources for every rule in the cloudformation template files, and finally deploy with the package parameter.

serverless package --stage $ENVIRONMENT
python remove_cloudformation_resources.py .serverless/serverless-state.json EventUnderscorerouterUnderscorecontrollerEventBridgeLambdaPermission
python remove_cloudformation_resources.py .serverless/cloudformation-template-update-stack.json EventUnderscorerouterUnderscorecontrollerEventBridgeLambdaPermission
serverless deploy --stage $ENVIRONMENT --package .serverless

This is the python code I used (remove_cloudformation_resources.py):

import json
import sys


def read_json_file(file):
    with open(file) as json_file:
        data = json.load(json_file)
    return data


def write_json_file(file, data):
    with open(file, 'w') as outfile:
        json.dump(data, outfile, indent=2)


def remove_resources_from_serverless_state(data, name):
    data_copy = data.copy()
    cloudformation_template = data["service"]["provider"]["compiledCloudFormationTemplate"]["Resources"]
    cloudformation_template_copy = cloudformation_template.copy()
    for resource_name, item in cloudformation_template.items():
        if item["Type"] == "AWS::Lambda::Permission" and resource_name.startswith(name):
            print("Removing resource: " + resource_name)
            cloudformation_template_copy.pop(resource_name, None)
    data_copy["service"]["provider"]["compiledCloudFormationTemplate"]["Resources"] = cloudformation_template_copy
    return data_copy

def remove_resources_from_cloudformation(data, name):
    data_copy = data.copy()
    cloudformation_template = data["Resources"]
    cloudformation_template_copy = cloudformation_template.copy()
    for resource_name, item in cloudformation_template.items():
        if item["Type"] == "AWS::Lambda::Permission" and resource_name.startswith(name):
            print("Removing resource: " + resource_name)
            cloudformation_template_copy.pop(resource_name, None)
    data_copy["Resources"] = cloudformation_template_copy
    return data_copy


if __name__ == "__main__":
    filename = sys.argv[1]
    resource_pattern = sys.argv[2]

    data = read_json_file(filename)
    if "serverless-state" in filename:
        data_fix = remove_resources_from_serverless_state(data, resource_pattern)
    elif "cloudformation-template" in filename:
        data_fix = remove_resources_from_cloudformation(data, resource_pattern)
    write_json_file(filename, data_fix)