events.EventBridgeEvent is returning an empty payload when called by the EventBridge Scheduler

[ryanparsa]

Hi guys,

I'm trying to invoke a Lambda function using EventBridge Scheduler, but I'm not receiving the JSON payload in the Lambda.

Here are the details:

Scheduler:

{
    "ActionAfterCompletion": "NONE",
    "Arn": "arn:aws:scheduler:us-east-1:?:schedule/default/backup1",
    "CreationDate": "2024-05-16T19:44:38.262000-07:00",
    "Description": "",
    "FlexibleTimeWindow": {
        "Mode": "OFF"
    },
    "GroupName": "default",
    "LastModificationDate": "2024-05-16T20:07:32.388000-07:00",
    "Name": "backup1",
    "ScheduleExpression": "cron(* * ? * * 2024)",
    "ScheduleExpressionTimezone": "America/?",
    "State": "ENABLED",
    "Target": {
        "Arn": "arn:aws:lambda:us-east-1:?:function:backup",
        "Input": "{\"backupID\": \"123\", \"key2\": \"value2\", \"key3\": \"value3\"}",
        "RetryPolicy": {
            "MaximumEventAgeInSeconds": 86400,
            "MaximumRetryAttempts": 0
        },
        "RoleArn": "arn:aws:iam::?:role/service-role/Amazon_EventBridge_Scheduler_LAMBDA"
    }
}

lambda:

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"log"
)



func LambdaHandler(ctx context.Context, event events.EventBridgeEvent) (*string, error) {
	fmt.Println("LambdaHandler")
	fmt.Printf("ctx: %#v\n", ctx)
	fmt.Printf("event: %#v\n", event)

	message := fmt.Sprintf("Hello %s!", "lambda")
	return &message, nil
}

func main() {
	lambda.Start(LambdaHandler)
}

cloud watch:

2024/05/17 04:17:20 im LambdaHandler
ctx: context.Background.WithDeadline(2024-05-17 04:17:23.103 +0000 UTC [2.999198593s]).WithValue(type *lambdacontext.key, val <not Stringer>).WithValue(type string, val Root=1-6646da50-1;Parent=1;Sampled=0;Lineage=a8ed5ba3:0)

event: {Version: ID: DetailType: Source: AccountID: Time:0001-01-01 00:00:00 +0000 UTC Region: Resources:[] Detail:[]}

go.mod

module backup

go 1.22.0

require (
	github.com/aws/aws-lambda-go v1.47.0 // indirect
	github.com/aws/aws-sdk-go-v2 v1.27.0 // indirect
	github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.6.2 // indirect
	github.com/aws/aws-sdk-go-v2/config v1.27.15 // indirect
	github.com/aws/aws-sdk-go-v2/credentials v1.17.15 // indirect
	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.16.3 // indirect
	github.com/aws/aws-sdk-go-v2/internal/configsources v1.3.7 // indirect
	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.6.7 // indirect
	github.com/aws/aws-sdk-go-v2/internal/ini v1.8.0 // indirect
	github.com/aws/aws-sdk-go-v2/internal/v4a v1.3.7 // indirect
	github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.11.2 // indirect
	github.com/aws/aws-sdk-go-v2/service/internal/checksum v1.3.9 // indirect
	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.11.9 // indirect
	github.com/aws/aws-sdk-go-v2/service/internal/s3shared v1.17.7 // indirect
	github.com/aws/aws-sdk-go-v2/service/s3 v1.54.2 // indirect
	github.com/aws/aws-sdk-go-v2/service/sso v1.20.8 // indirect
	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.24.2 // indirect
	github.com/aws/aws-sdk-go-v2/service/sts v1.28.9 // indirect
	github.com/aws/smithy-go v1.20.2 // indirect
)

It appears that the events.EventBridgeEvent object in the Lambda function is empty. Any ideas on what might be causing this or how to fix it?

Thanks!

[perriea]

Same problem..
@ryanparsa have you found it where the problem is ?

[skynet2]

Ok, it looks like I found out how it works.
When you specify Input for your cloudwatch schedule

Instead of receiving events.CloudWatchEvent, you will receive RAW input.

Instead of events.CloudWatchEvent, you need to use a struct to which you can parse your custom input.