tomodachi 0.7.0

``tomodachi`` - a lightweight microservices framework with asyncio
==============================================================
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Python 3 microservice framework using asyncio (async / await) with HTTP,
websockets, 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 🌟
---------------------------
.. code:: python

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


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

# 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 the service 😎
------------------
.. code:: bash

  # if installed via pip
  $ tomodachi run service.py

# if cloned from repo
$ python tomodachi.py run service.py


.. code:: bash

tomodachi/X.X.XX
October 02, 2017 - 13:38:00,481516
Quit services with <ctrl+c>.
2017-10-02 13:38:01,234 (services.service): Initializing service "example" [id: <uuid>]
2017-10-02 13:38:01,248 (transport.http): Listening [http] on http://127.0.0.1:9700/
2017-10-02 13:38:01,248 (services.service): Started service "example" [id: <uuid>]


.. code:: bash

$ curl -v "http://127.0.0.1:9700/resource/1234"
< HTTP/1.1 200 OK
< Content-Type: text/plain; charset=utf-8
< Server: tomodachi
< Content-Length: 9
< Date: Mon, 02 Oct 2017 13:38:02 GMT
id = 1234


Requirements 👍
---------------
* Python_ 3.5+
* aiohttp_
* aiobotocore_
* aioamqp_
* ujson_
* uvloop_

.. _Python: https://www.python.org
.. _asyncio: http://docs.python.org/3.5/library/asyncio.html
.. _aiohttp: https://github.com/aio-libs/aiohttp
.. _aiobotocore: https://github.com/aio-libs/aiobotocore
.. _aioamqp: https://github.com/Polyconseil/aioamqp
.. _ujson: https://github.com/esnme/ultrajson
.. _uvloop: https://github.com/MagicStack/uvloop


License 🙋
----------
Offered under the `MIT license <https://github.com/kalaspuff/tomodachi/blob/master/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 <https://github.com/kalaspuff/tomodachi/blob/master/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
=======

0.7.0 (2018-01-27)
------------------

- Added `@websocket` as a decorator type for handling websockets. A function
call should return two callables which will be used for receiving messages
through the socket and as a way to notify about the closure of the socket.


0.6.5 (2018-01-16)
------------------

- Updated `aiohttp` to latest version which solves incompabilities with `yarl`.


0.6.4 (2018-01-15)
------------------

- Added a stricter dependency check for `yarl`.


0.6.3 (2018-01-12)
------------------

- Gracefully handle exceptions thrown when receiving messages from AWS SNS+SQS.
For example when invalid XML data in response which causes botocore to throw
a botocore.parsers.ResponseParserError.

- Updated dependencies to allow for newer version of aiohttp 2.3.X.

- Improved type hinting.


0.6.2 (2017-11-15)
------------------

- Recreate queues and resubscribe to topics if queue is removed during runtime.


0.6.1 (2017-11-15)
------------------

- Introduced new options for AWS SNS/SQS transport to use `aws_endpoint_urls`
for `sns` and `sqs` if the user wishes to connect to other endpoints and the
actual AWS endpoints, which could be useful for development and testing. The
AWS SNS/SQS examples has been updated with values to reflect these options.

- Reworked timeouts and reconnects and fixed an issue in the recreate_client
method which was called on server disconnects.


0.6.0 (2017-11-15)
------------------

- Stricter version control of required packages to not break installation on
major/minor related updates.

- Updates to support aiohttp 2.3.X and aiobotocore 0.5.X.


0.5.3 (2017-11-08)
------------------

- Corrects issues on timeouts and server disconnects.

- Specify fixed version for aiohttp to not break installation.

- Code cleanup to conform with pycodestyle.


0.5.2 (2017-10-08)
------------------

- Add argument option for log level as '-l' or '--log'. (github: **djKooks**)

- Better matching of imported modules on hot-reload which will cause reloading
into code with syntax errors or indentation errors much harder.


0.5.1 (2017-10-03)
------------------

- More improvements regarding hot-reloading of code that may have syntax errors,
indentation errors or issues when the service is being initiated.


0.5.0 (2017-10-02)
------------------

- Solves the issue where hot-loading into a state where the code errors due to
syntax errors would crash the application, making the user need to manually
restart the process.


0.4.10 (2017-10-02)
-------------------

- Fixes for failing tests on hot-reloading during test phase.


0.4.9 (2017-10-02)
------------------

- Solves issue with Segmentation fault in Python 3.6 during hot-reload on
Linux.


0.4.8 (2017-10-02)
------------------

- Fixes type hinting issues with Python 3.5.1.


0.4.7 (2017-09-30)
------------------

- Reworked watcher since it ended up using 90% CPU of the running core due to
constant re-indexing (mstat) of every file every 0.5s. Full re-index will now
only run every 10 seconds, since it's more rare that new files are added than
existing files edited. Watcher for edited existing files will still run at the
same intervals.

- Watched file types may now be specified via configuration via
``options.watcher.watched_file_endings``.


0.4.6 (2017-09-29)
------------------

- Messages via SNS+SQS or AMQP over 60000 bytes as JSON will now be sent in a
gzipped base64 encoded format to allow for larger limits and lower potential
SNS costs due to multiplexed messaging.

- Fixes an issue with multidict 3.2.0 on hot-reload which made the tomodachi
application crash.


0.4.5 (2017-09-07)
------------------

- Possibility to requeue messages that result in specific exceptions.
Exceptions that will nack the message (for AMQP transport) is called
``AmqpInternalServiceError``. Exceptions that won't delete the message from
the queue and in turn will result in it to "reappear" unless configured
non-default (for AWS SNS+SQS transport) is called
``AWSSNSSQSInternalServiceError``.


0.4.4 (2017-08-25)
------------------

- Corrected an issue regarding crontab notation for scheduling function calls
where it didn't parse the upcoming date correctly if both isoweekday and day
part were given.


0.4.3 (2017-08-09)
------------------

- Catches unintended HTTP exceptions and prints a useful stacktrace if log_level
is set to DEBUG.


0.4.2 (2017-08-07)
------------------

- Fixes an issue where Content-Type header couldn't be specified without
charset in HTTP transports.

- Cleared some old debug code.


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``.