tomodachi 0.4.1

Python 3 microservice library / framework using asyncio with HTTP, AMQP and AWS SNS+SQS support.

tomodachi - a lightweight microservices framework with asyncio

Python 3 microservice framework using asyncio (async / await) with HTTP, RabbitMQ / AMQP and AWS SNS+SQS support for event bus based communication.

Tomodachi is a tiny framework designed to build fast microservices listening on HTTP or communicating over event driven message buses like RabbitMQ, AMQP, AWS (Amazon Web Services) SNS+SQS, etc. It’s designed to be extendable to make use of any type of transport layer available.

Tomodachi (友達) means friends – and since microservices wouldn’t make sense on their own I think they need to be friends with each other. 😍 👬 👭 👫

How do I use this?

Installation via pip 🌮

$ pip install tomodachi

Basic HTTP based service 🌟

import tomodachi
from tomodachi.transport.http import http, http_error


@tomodachi.service
class Service(object):
    name = 'example_service'

    # Request paths are specified as regex for full flexibility
    @http('GET', r'/resource/(?P<id>[^/]+?)/?')
    async def resource(self, request, id):
        # Returning a string value normally means 200 OK
        return 'id = {}'.format(id)

    @http('GET', r'/health')
    async def health_check(self, request):
        # Return can also be a tuple, dict or even an aiohttp.web.Response
        # object for more complex responses - for example if you need to
        # send byte data, set your own status code or define own headers
        return {
            'body': 'Healthy',
            'status': 200
        }

    # Specify custom 404 catch-all response
    @http_error(status_code=404)
    async def error_404(self, request):
        return 'error 404'

Run service 😎

$ tomodachi run service.py

Requirements 👍

• Python 3.5+

• aiohttp

• aiobotocore

• aioamqp

• ujson

• uvloop

License 🙋

Offered under the MIT license

Source code 🦄

The latest developer version of tomodachi is available at the GitHub repo https://github.com/kalaspuff/tomodachi

Any questions?

What is the best way to run a tomodachi service?

There is no way to tell you how to orchestrate your infrastructure. Some people may run it containerized in a Docker environment, deployed via Terraform and some may run several services on the same environment, on the same machine. There are no standards and we’re not here to tell you about your best practices.

Are there any more example services?

There are a few examples in the examples folder, including examples to publish events/messages to an AWS SNS topic and subscribe to an AWS SQS queue. There’s also a similar example of how to work with pub-sub for RabbitMQ via AMQP transport protocol.

Why should I use this?

I’m not saying you should, but I’m not saying you shouldn’t. tomodachi is a perfect place to start when experimenting with your architecture or trying out a concept for a new service. It may not have all the features you desire and it may never do.

Should I run this in production?

It’s all still highly experimental and it depends on other experimental projects, so you have to be in charge here and decide for yourself. Let me know if you do however!

Who built this and why?

My name is Carl Oscar Aaro and I’m a coder from Sweden. I simply wanted to learn more about asyncio and needed a constructive off-work project to experiment with – and here we are. 🎉

Changes

0.4.1 (2017-08-05)

• Corrects and issue with AMQP transport which caused invoked functions to not be able to declare scope variables without crashes.

0.4.0 (2017-08-05)

• Release fixes a major issue which caused invoked functions to not be able to declare any scope variables.

• @http_static decorator for serving static files from a folder on disk. Takes to values; 1. the path to the folder, either relative to the service file or absolute; 2. the base URL path for static files as a regexp.

0.3.0 (2017-07-25)

• Changed format of access log for HTTP requests - now logging user agent and login name (if authorization via Basic Auth).

• Support for X-Forwarded-For headers via real_ip_from and real_ip_header options which will log the forwarded IP instead of the one from the load balancer / proxy.

• Access log for HTTP can now be specified as a filename to which the service will log all requests.

• Fixes issue with schedule invoker which would crash if invoked at second 0.

• Updated dependencies to latest available versions.

0.2.17 (2017-07-05)

• Timezone support for schedule invoker functions.

• Added more decorator invoker functions as aliases for common scheduler use cases - @minutely, @hourly, @daily and @heartbeat (every second)

• Updated example services and better test cases.

• Updated aiohttp / aiobotocore / botocore dependencies.

0.2.16 (2017-07-02)

• Solved issues with aiobotocore / aiohttp dependencies.

• Refactored loader functions.

0.2.15 (2017-07-02)

• Corrected issue with configuration values for AWS and AWS SNS+SQS settings.

• Improved testing suite and more code coverage for integration tests.

0.2.14 (2017-06-30)

• New “transport” invoker for service functions: schedule. It works like cron type scheduling where specific functions will be run on the specified interval. For example a function can be specified to run once per day at a specific time or every second minute, or the last Tuesday of January and March at 05:30 AM.

• Values for keyword arguments invoked by transport decorators were earlier always set to None, despite having other default values. This is now corrected.

0.2.13 (2017-06-20)

• Type hinted examples and test cases.

• Shielded function calls for AMQP and SNS+SQS transports to avoid unexpected execution stop.

• Added version output to tomodachi CLI tool.

• Additional test cases.

0.2.12 (2017-06-18)

• Type hinted code base and minor bug fixes for internal functions.

0.2.11 (2017-06-09)

• Invoker methods can now be called directly without the need to mock the invoker decorator function.

0.2.10 (2017-06-08)

• Added @functools.wraps decorator to invoked functions of service classes.

0.2.9 (2017-06-06)

• Added a list of safe modules that may never be removed from the list of already loaded modules. Removing the module ‘typing’ from the list would cause a RecursionError exception since Python 3.6.1.

0.2.8 (2017-05-23)

• Additional improvements to network connectivity issues to not get stuck in waiting state.

0.2.7 (2017-05-23)

• Improved SNS+SQS draining / restart when network connectivity has been lost or temporarily suspended. Would improve situations when development machine has been in hibernation.

• Replaced deprecated logging functions to rid warnings.

0.2.6 (2017-05-22)

• Support for a “generic” aws dictonary in options that can hold region, access key id and secret to be shared among other AWS resources/services.

• Updated aiobotocore / botocore dependencies.

• Gracefully handle and discard invalid SNS/SQS messages not in JSON format.

• Corrected issue where watched directories with “similar” names as settings would be ignored.

0.2.5 (2017-05-16)

• Updated issues with function caching due to keepalive when hot reloading in development. Currently disables keepalive entirely.

• Fixed issue with updated file logging for watcher.

0.2.4 (2017-05-12)

• Downgraded botocore to meet requirements and to make the installed tomodachi script runnable again.

0.2.3 (2017-05-10)

• Watcher is now configurable to ignore specific directories dependant on the service. (github: smaaland)

• Fixed issue where using --config instead of -c would result in a raised exception. (github: smaaland)

0.2.2 (2017-05-04)

• tomodachi.transport.http has its own Response object that works better with default content types and charsets - examples/http_service.py updated.

• No automatic conversion will be tried if the returned response of an http method is of bytes type.

0.2.1 (2017-05-03)

• Improved handling of how charsets and encodings work with aiohttp.

• Fixed an issue where Content-Type header would always be included twice for aiohttp.web.Response objects.

0.2.0 (2017-05-02)

• Watcher now only reacts to files with file endings .py, .json, .yml, .html or .html and ignores to look at paths __pycache__, .git, .svn, __ignored__, __temporary__ and __tmp__.

• HTTP transport may now respond with an aiohttp.web.Response object for more complex responses.

• HTTP transport response headers can now use the multidict library.

0.1.11 (2017-04-02)

• Working PyPI release.

• Added unit tests.

• Works with aiohttp 2 and aiobotocore 0.3.

• Service classes must be decorated with @tomodachi.service.