https://github.com/Nextdoor/ndscheduler
A flexible python library for building your own cron-like system, with REST APIs and a Web UI.
https://github.com/Nextdoor/ndscheduler
Last synced: about 1 year ago
JSON representation
A flexible python library for building your own cron-like system, with REST APIs and a Web UI.
- Host: GitHub
- URL: https://github.com/Nextdoor/ndscheduler
- Owner: Nextdoor
- License: bsd-2-clause
- Created: 2015-07-30T17:41:48.000Z (almost 11 years ago)
- Default Branch: master
- Last Pushed: 2024-11-15T15:07:56.000Z (over 1 year ago)
- Last Synced: 2025-05-11T18:04:27.190Z (about 1 year ago)
- Language: Python
- Homepage:
- Size: 401 KB
- Stars: 1,101
- Watchers: 48
- Forks: 201
- Open Issues: 43
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
Awesome Lists containing this project
README
# Nextdoor Scheduler
[](https://travis-ci.org/Nextdoor/ndscheduler)
``ndscheduler`` is a flexible python library for building your own cron-like system to schedule jobs, which is to run a tornado process to serve REST APIs and a web ui.
Check out our blog post - [We Don't Run Cron Jobs at Nextdoor](https://engblog.nextdoor.com/we-don-t-run-cron-jobs-at-nextdoor-6f7f9cc62040#.d2erw1pl6)
**``ndscheduler`` currently supports Python 2 & 3 on Mac OS X / Linux.**
## Table of contents
* [Key Abstractions](#key-abstractions)
* [Try it NOW](#try-it-now)
* [How to build Your own cron-replacement](#how-to-build-your-own-cron-replacement)
* [Install ndscheduler](#install-ndscheduler)
* [Three things](#three-things)
* [Reference Implementation](#reference-implementation)
* [Contribute code to ndscheduler](#contribute-code-to-ndscheduler)
* [REST APIs](#rest-apis)
* [Web UI](#web-ui)
## Key Abstractions
* [CoreScheduler](https://github.com/Nextdoor/ndscheduler/tree/master/ndscheduler/corescheduler): encapsulates all core scheduling functionality, and consists of:
* [Datastore](https://github.com/Nextdoor/ndscheduler/tree/master/ndscheduler/corescheduler/datastore): manages database connections and makes queries; could support Postgres, MySQL, and sqlite.
* Job: represents a schedule job and decides how to run a paricular job.
* Execution: represents an instance of job execution.
* AuditLog: logs when and who runs what job.
* [ScheduleManager](https://github.com/Nextdoor/ndscheduler/blob/master/ndscheduler/corescheduler/scheduler_manager.py): access Datastore to manage jobs, i.e., schedule/modify/delete/pause/resume a job.
* [Server](https://github.com/Nextdoor/ndscheduler/tree/master/ndscheduler/server): a tornado server that runs ScheduleManager and provides REST APIs and serves UI.
* [Web UI](https://github.com/Nextdoor/ndscheduler/tree/master/ndscheduler/static): a single page HTML app; this is a default implementation.
Note: ``corescheduler`` can also be used independently within your own service if you use a different Tornado server / Web UI.
## Try it NOW
From source code:
git clone https://github.com/Nextdoor/ndscheduler.git
cd ndscheduler
make simple
Or use docker:
docker run -it -p 8888:8888 wenbinf/ndscheduler
Open your browser and go to [localhost:8888](http://localhost:8888).
**Demo**
(Click for fullscreen play)
## How to build Your own cron-replacement
### Install ndscheduler
Using pip (from GitHub repo)
#
# Put this in requirements.txt, then run
# pip install -r requirements.txt
#
# If you want the latest build
git+https://github.com/Nextdoor/ndscheduler.git#egg=ndscheduler
# Or put this if you want a specific commit
git+https://github.com/Nextdoor/ndscheduler.git@5843322ebb440d324ca5a66ba55fea1fd00dabe8
# Or put this if you want a specific tag version
git+https://github.com/Nextdoor/ndscheduler.git@v0.1.0#egg=ndscheduler
#
# Run from command line
#
pip install -e git+https://github.com/Nextdoor/ndscheduler.git#egg=ndscheduler
(We'll upload the package to PyPI soon.)
### Three things
You have to implement three things for your scheduler, i.e., ``Settings``, ``Server``, and ``Jobs``.
**Settings**
In your implementation, you need to provide a settings file to override default settings (e.g., [settings in simple_scheduler](https://github.com/Nextdoor/ndscheduler/blob/master/simple_scheduler/settings.py)). You need to specify the python import path in the environment variable ``NDSCHEDULER_SETTINGS_MODULE`` before running the server.
All available settings can be found in [default_settings.py](https://github.com/Nextdoor/ndscheduler/blob/master/ndscheduler/default_settings.py) file.
**Server**
You need to have a server file to import and run ``ndscheduler.server.server.SchedulerServer``.
**Jobs**
Each job should be a standalone class that is a subclass of ``ndscheduler.job.JobBase`` and put the main logic of the job in ``run()`` function.
After you set up ``Settings``, ``Server`` and ``Jobs``, you can run the whole thing like this:
NDSCHEDULER_SETTINGS_MODULE=simple_scheduler.settings \
PYTHONPATH=.:$(PYTHONPATH) \
python simple_scheduler/scheduler.py
### Upgrading
It is best practice to backup your database before doing any upgrade. ndscheduler relies on [apscheduler](https://apscheduler.readthedocs.io/en/latest/) to serialize jobs to the database, and while it is usually backwards-compatible (i.e. jobs created with an older version of apscheduler will continue to work after upgrading apscheduler) this is not guaranteed, and it is known that downgrading apscheduler can cause issues. See [this PR comment](https://github.com/Nextdoor/ndscheduler/pull/54#issue-262152050) for more details.
### Reference Implementation
See code in the [simple_scheduler/](https://github.com/Nextdoor/ndscheduler/tree/master/simple_scheduler) directory for inspiration :)
Run it
make simple
Access the web ui via [localhost:8888](http://localhost:8888)
The reference implementation also comes with [several sample jobs](https://github.com/Nextdoor/ndscheduler/tree/master/simple_scheduler/jobs).
* AwesomeJob: it just prints out 2 arguments you pass in.
* SlackJob: it sends a slack message periodically, for example, team standup reminder.
* ShellJob: it runs an executable command, for example, run curl to crawl web pages.
* CurlJob: it's like running [curl](http://curl.haxx.se/) periodically.
And it's [dockerized](https://github.com/Nextdoor/ndscheduler/tree/master/simple_scheduler/docker).
## Contribute code to ndscheduler
**Install dependencies**
# Each time we introduce a new dependency in setup.py, you have to run this
make install
**Run unit tests**
make test
**Clean everything and start from scratch**
make clean
Finally, send pull request. Please make sure the [CI](https://travis-ci.org/Nextdoor/ndscheduler) passes for your PR.
## REST APIs
Please see [README.md in ndscheduler/server/handlers](https://github.com/Nextdoor/ndscheduler/blob/master/ndscheduler/server/handlers/README.md).
## Web UI
We provide a default implementation of web ui. You can replace the default web ui by overwriting these settings
STATIC_DIR_PATH = :static asset directory paths:
TEMPLATE_DIR_PATH = :template directory path:
APP_INDEX_PAGE = :the file name of the single page app's html:
### The default web ui
**List of jobs**
**List of executions**
**Audit Logs**
**Modify a job**
