initial commit

Author: Jimmy Bradshaw

.gitignore

@@ -0,0 +1,144 @@
+.idea/
+
+# Created by .ignore support plugin (hsz.mobi)
+### Python template
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+pip-wheel-metadata/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+

README.md

@@ -0,0 +1,34 @@
+# Nameko Cron
+
+Nameko `Cron` entrypoint fires based on a cron expression. It is not cluster-aware and
+will fire on all service instances. The cron schedule is based on [croniter](http://github.com/kiorky/croniter).
+
+## Usage
+
+```python
+from nameko_cron import cron
+
+
+class Service:
+    name ="service"
+
+    @cron('*/5 * * * *')
+    def ping(self):
+        # executes every 5 minutes
+        print("pong")
+```
+
+timezone-aware cron schedules are also available
+
+```python
+from nameko_cron import cron
+
+
+class Service:
+    name ="service"
+
+    @cron('0 12 * * *', tz='America/Chicago')
+    def ping(self):
+        # executes every day at noon America/Chicago time
+        print("pong")
+```

nameko_cron/__init__.py

@@ -0,0 +1,99 @@
+import datetime
+import time
+from logging import getLogger
+
+from croniter import croniter
+from eventlet import Timeout
+from eventlet.event import Event
+import pytz
+
+from nameko.extensions import Entrypoint
+
+
+_log = getLogger(__name__)
+
+
+class Cron(Entrypoint):
+    def __init__(self, schedule, tz=None, **kwargs):
+        """
+        Cron entrypoint. Fires according to a (possibly timezone-aware)
+        cron schedule. If no timezone info is passed, the default is UTC.
+
+        Example::
+
+            class Service(object):
+                name = "service"
+
+            @cron(schedule='0 12 * * *', tz='America/Chicago')
+            def ping(self):
+                # method executes every day at noon America/Chicago time
+                print("pong")
+
+        """
+        self.schedule = schedule
+        self.tz = tz
+        self.should_stop = Event()
+        self.worker_complete = Event()
+        self.gt = None
+        super().__init__(**kwargs)
+
+    def start(self):
+        _log.debug('starting %s', self)
+        self.gt = self.container.spawn_managed_thread(self._run)
+
+    def stop(self):
+        _log.debug('stopping %s', self)
+        self.should_stop.send(True)
+        self.gt.wait()
+
+    def kill(self):
+        _log.debug('killing %s', self)
+        self.gt.kill()
+
+    def _get_next_interval(self):
+        now_utc = datetime.datetime.now(tz=pytz.UTC)
+        if self.tz:
+            tz = pytz.timezone(self.tz)
+            base = now_utc.astimezone(tz)
+        else:
+            base = now_utc
+        cron_schedule = croniter(self.schedule, base)
+        while True:
+            yield max(cron_schedule.get_next() - time.time(), 0)
+
+    def _run(self):
+        """ Runs the schedule loop. """
+        interval = self._get_next_interval()
+        sleep_time = next(interval)
+        while True:
+            # sleep for `sleep_time`, unless `should_stop` fires, in which
+            # case we leave the while loop and stop entirely
+            with Timeout(sleep_time, exception=False):
+                self.should_stop.wait()
+                break
+
+            self.handle_timer_tick()
+
+            self.worker_complete.wait()
+            self.worker_complete.reset()
+
+            sleep_time = next(interval)
+
+    def handle_timer_tick(self):
+        args = ()
+        kwargs = {}
+
+        # Note that we don't catch ContainerBeingKilled here. If that's raised,
+        # there is nothing for us to do anyway. The exception bubbles, and is
+        # caught by :meth:`Container._handle_thread_exited`, though the
+        # triggered `kill` is a no-op, since the container is already
+        # `_being_killed`.
+        self.container.spawn_worker(
+            self, args, kwargs, handle_result=self.handle_result)
+
+    def handle_result(self, worker_ctx, result, exc_info):
+        self.worker_complete.send()
+        return result, exc_info
+
+
+cron = Cron.decorator

setup.py

@@ -0,0 +1,27 @@
+import setuptools
+
+with open("README.md", "r") as fh:
+    long_description = fh.read()
+
+setuptools.setup(
+    name="nameko-cron",
+    version="0.0.1",
+    author="bradshjg",
+    author_email="[email protected]",
+    description="Nameko cron extension",
+    long_description=long_description,
+    long_description_content_type="text/markdown",
+    url="https://github.com/bradshjg/nameko-cron",
+    packages=setuptools.find_packages(exclude=['tests']),
+    classifiers=[
+        "Programming Language :: Python :: 3",
+        "License :: OSI Approved :: MIT License",
+        "Operating System :: OS Independent",
+    ],
+    python_requires='>=3.6',
+    install_requires=[
+        'croniter',
+        'nameko',
+        'pytz'
+    ]
+)