When you create a Lambda permission you send the __statement id__ as mandatory parameter.

https://docs.aws.amazon.com/lambda/latest/dg/API_AddPermission.html#API_AddPermission_RequestSyntax

However this id is generated by a random value. 

https://github.com/localstack/localstack/blob/b3917bf248b77ced8ef80a3d5c0561960066db5d/localstack/services/awslambda/lambda_api.py#L927

Due to this problem, the tools like Terraform or Ansible fail when it has to be retrieved to check the existence of this element.

If you agree I could make a PR with the fix and its test.
import re
import os
import json
import time
import unittest
import six
from io import BytesIO
from localstack import config
from localstack.constants import LOCALSTACK_ROOT_FOLDER, LOCALSTACK_MAVEN_VERSION
from localstack.utils import testutil
from localstack.utils.aws import aws_stack
from localstack.utils.common import (
    short_uid, load_file, to_str, mkdir, download, run_safe, get_free_tcp_port, get_service_protocol)
from localstack.services.infra import start_proxy