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.
self.check_lambda_logs(TEST_LAMBDA_NAME_DOTNETCORE2, expected_lines=expected)
        
        testutil.delete_lambda_function(TEST_LAMBDA_NAME_DOTNETCORE2)
class TestRubyRuntimes(LambdaTestBase):
    @classmethod
    def setUpClass(cls):
        cls.lambda_client = aws_stack.connect_to_service('lambda')
    def test_ruby_lambda_running_in_docker(self):
        if not use_docker():
            return
        zip_file = testutil.create_zip_file(
            TEST_LAMBDA_RUBY, get_content=True)
        testutil.create_lambda_function(
            func_name=TEST_LAMBDA_NAME_RUBY,
            zip_file=zip_file,
            handler='lambda_integration.handler',
            runtime=LAMBDA_RUNTIME_RUBY25
        )
        result = self.lambda_client.invoke(
            FunctionName=TEST_LAMBDA_NAME_RUBY, Payload=b'{}')
        result_data = result['Payload'].read()
        self.assertEqual(result['StatusCode'], 200)
        self.assertEqual(to_str(result_data).strip(), '{}')
        
        testutil.delete_lambda_function(TEST_LAMBDA_NAME_RUBY)
class TestJavaRuntimes(LambdaTestBase):
    @classmethod
    def setUpClass(cls):
        cls.lambda_client = aws_stack.connect_to_service('lambda')