AWS supports the following Ruby runtimes:

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Name | Identifier | SDK for Ruby | Operating system
-- | -- | -- | --
Ruby 2.7 | ruby2.7 | 3.0.1 | Amazon Linux 2
Ruby 2.5 | ruby2.5 | 3.0.1 | Amazon Linux

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Currently, `localstack/lambda` only contains the `ruby2.5` tag. Will the 2.7 runtime be supported in the (near) future?
invocation_uri = 'arn:aws:apigateway:%s:lambda:path/2015-03-31/functions/%s/invocations'
        target_uri = invocation_uri % (aws_stack.get_region(), lambda_uri)
        result = testutil.connect_api_gateway_to_http_with_lambda_proxy(
            'test_gateway2', target_uri, path=lambda_resource, stage_name=TEST_STAGE_NAME)
        api_id = result['id']
        url = gateway_request_url(api_id=api_id, stage_name=TEST_STAGE_NAME, path=lambda_path)
        result = safe_requests.post(url, data=b'{}', headers={'User-Agent': 'python-requests/testing'})
        content = json.loads(result.content)
        self.assertEqual(content['path'], lambda_path)
        self.assertEqual(content['resource'], lambda_resource)
        self.assertEqual(content['requestContext']['path'], lambda_request_context_path)
        self.assertEqual(content['requestContext']['resourcePath'], lambda_request_context_resource_path)
        
        testutil.delete_lambda_function(lambda_name)
    def test_upload_lambda_from_s3(self):
        lambda_name = 'test_lambda_%s' % short_uid()
        bucket_name = 'test-bucket-lambda'
        bucket_key = 'test_lambda.zip'
        
        zip_file = testutil.create_lambda_archive(
            load_file(TEST_LAMBDA_PYTHON), get_content=True,
            libs=TEST_LAMBDA_LIBS, runtime=LAMBDA_RUNTIME_PYTHON27)
        self.s3_client.create_bucket(Bucket=bucket_name)
        self.s3_client.upload_fileobj(
            BytesIO(zip_file), bucket_name, bucket_key)
        
        self.lambda_client.create_function(
            FunctionName=lambda_name, Handler='handler.handler',
            Runtime=LAMBDA_RUNTIME_PYTHON27, Role='r1',
            Code={'S3Bucket': bucket_name, 'S3Key': bucket_key}