I'm trying to setup an lambda function triggered by S3 events within a localstack docker-compose environment.
I've got the latest localstack image running in one service with S3, Lambda and APIGATEWAY and the second service is using `awslocal` to communicate with the localstack.

I have gotten as far as successfully creating a lambda function but when I attempt to `add-permission` I get a 404 Not Found error.

My command is:
```
awslocal lambda add-permission 
--function-name my-lambda-function 
--action lambda:InvokeFunction 
--statement-id s3 
--principal s3.amazonaws.com 
--source-arn arn:aws:s3:::event-source-bucket
```

This works against AWS so I'm not sure what I need to have setup within localstack to get it working.  Thanks for any insight you may have.
result = []
    for m in event_source_mappings:
        if not func_name or (m['FunctionArn'] in [func_name, func_arn(func_name)]):
            if not source_arn or (m['EventSourceArn'].startswith(source_arn)):
                result.append(m)
    return result
def get_function_version(arn, version):
    func = arn_to_lambda.get(arn)
    return format_func_details(func, version=version, always_add_version=True)
def publish_new_function_version(arn):
    func_details = arn_to_lambda.get(arn)
    versions = func_details.versions
    last_version = func_details.max_version()
    versions[str(last_version + 1)] = {
        'CodeSize': versions.get('$LATEST').get('CodeSize'),
        'CodeSha256': versions.get('$LATEST').get('CodeSha256'),
        'Function': versions.get('$LATEST').get('Function'),
        'RevisionId': str(uuid.uuid4())
    }
    return get_function_version(arn, str(last_version + 1))
def do_list_versions(arn):
    return sorted([get_function_version(arn, version) for version in
                   arn_to_lambda.get(arn).versions.keys()], key=lambda k: str(k.get('Version')))
def do_update_alias(arn, alias, version, description=None):
    new_alias = {
        'AliasArn': arn + ':' + alias,
        'FunctionVersion': version,
        'Name': alias,
        'Description': description or '',
        'RevisionId': str(uuid.uuid4())