To build the lambda zip.
Do the following

1. copy following code in main.go and buld the lambda

```
package main

import (
	"context"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
)

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

func handler(ctx context.Context, e events.DynamoDBEvent) error {
	return nil
}
```

2. build the binary
```
GOOS=linux go build -o main .
```

3. zip the binary
```
zip lambda.zip main
```
