Metadata-Version: 1.0
Name: cronq
Version: 0.15.0
Summary: A Cron-like system for running tasks
Home-page: https://github.com/seatgeek/cronq
Author: SeatGeek
Author-email: opensource@seatgeek.com
License: BSD
Description: =====
        CronQ
        =====
        
        A cron-like system to run your application tasks across any node, instead of one special snowflake. This is done by keeping your tasks in MySQL and publishing them over AMQP to workers that will run your tasks and eventually save the results back into the DB. This was started as a hackathon project at SeatGeek_
        
        Requirements
        ============
        
        - Python 2.7
        - RabbitMQ 3.x
        - MySQL 5.x
        
        Installation
        ============
        
        Using PIP via PyPi::
        
            pip install cronq
        
        Using PIP via Github::
        
            pip install git+git://github.com/seatgeek/cronq.git@0.15.0#egg=cronq
        
        Adding to your ``requirements.txt`` file (run ``pip install -r requirements.txt`` afterwards)::
        
            git+ssh://git@github.com/seatgeek/python-cronq.git@0.15.0#egg=cronq
        
        Usage
        =====
        
        There are various workers that are used by Cronq, as well as a web admin.
        
        cronq-runner
        ============
        
        The ``runner`` executes tasks, and should be run on hosts that will actually perform work. There is no limit to the number of runners that can execute.
        
        The runner requires ``/var/log/cronq/`` to exist and be writable by the user executing the runner. If it is not, logs will be written to ``/tmp``.
        
        .. code-block:: bash
        
            # setup rabbitmq connection info
            export RABBITMQ_HOST=localhost
            export RABBITMQ_USER=guest
            export RABBITMQ_PASS=guest
        
            # specify the rabbitmq queue to listen to
            export CRONQ_QUEUE=cronq_jobs # `cronq_jobs` is the default queue
        
            # log job output to stdout *as well as* /var/log/cronq
            export CRONQ_RUNNER_LOG_TO_STDOUT=1
        
            # run commands
            cronq-runner
        
        When run, `cronq-runner` will:
        
        - Setup a rabbitmq connection
        - Listen to the `cronq_jobs` queue
        - Retrieve commands from the queue
        - Publish a message saying the command is started
        - Run the command in a shell subprocess
        - Publish a message on success/failure to the ``cronq`` exchange and ``cronq_results`` queue. This is not configurable.
        - Listen for more messages
        
        cronq-injector
        ==============
        
            The ``cronq-injector`` command will non-destructively create any necessary ``cronq`` tables, though it will need a database to perform this action against. Please note that if you do not have tables created, it is helpful to run the injector first.
        
        The ``injector`` is used to retrieve jobs from the database and publish them to AMQP. Jobs are published in the following format:
        
        .. code-block:: python
        
            # where job is a database record
            {
                'name': job.name,
                'command': unicode(job.command),
                'id': job.id,
            }
        
        You can ostensibly run as many injectors as necessary. MySQL isolation levels are used to attain locks on job records.
        
        .. code-block:: bash
        
            # setup rabbitmq connection info
            export RABBITMQ_HOST=localhost
            export RABBITMQ_USER=guest
            export RABBITMQ_PASS=guest
        
            # specify the database connection string
            export CRONQ_MYSQL=mysql+pymysql://cronq:cronq@localhost/cronq
        
            # run the comand injector
            cronq-injector
        
        ``cronq-injector`` perform a 1 second sleep between job injections, but may perform an unlimited number of job injections in that time period.
        
        Note that jobs are not queued up at the *exact* time you specify in the database. Rather, jobs that matches the following heuristic are queued one-at-a-time until no jobs are left to be queued for that injection cycle::
        
            Job.next_run < NOW() OR Job.run_now = 1
        
        cronq-results
        =============
        
        The `results` aggregator listens to the ``cronq_results`` queue for the results of ``cronq-runner`` executions. You can run as many of these as possible, as they will retrieve results one-at-a-time from rabbitmq.
        
        .. code-block:: bash
        
            # setup rabbitmq connection info
            export RABBITMQ_HOST=localhost
            export RABBITMQ_USER=guest
            export RABBITMQ_PASS=guest
        
            # specify the database connection string
            export CRONQ_MYSQL=mysql+pymysql://cronq:cronq@localhost/cronq
        
            # run the results-aggregator
            cronq-results
        
        These results can be viewed for particular commands within the web-admin, or by inspecting the database.
        
        cronq-web
        =========
        
        The web view is a WSGI app run from ``cronq.web:app`` and requires only database access. The following is an example for running the web admin using webscale technologies:
        
        .. code-block:: bash
        
            # install libevent-dev
            sudo apt-get install libevent-dev
        
            # install required python libraries
            sudo pip install greenlet gevent gunicorn
        
            # specify the database connection string
            export CRONQ_MYSQL=mysql+pymysql://cronq:cronq@localhost/cronq
        
            # if you have an aggregated log dashboard, you can provide a search url
            # template. it will be used in the web dashboard for linking to logs
            # the following strings will be replaced:
            #
            # {job_id} : replaced with the job's job_id
            # {run_id} : replaced with the job's run_id
            # {start_time} : replaced with job's start time in ISO format url quoted
            #                ex - "2016-08-15T08%3A00%3A11.000Z"
            # {end_time} : replaced with job's end time, or now if job is still running, in ISO format url quoted
                           ex - "2016-08-15T08%3A00%3A31.999Z"
            export CRONQ_LOG_URL_TEMPLATE="https://logs.service/search?run_id={run_id}&from={start_time}&to={end_time}"
        
            # run the web admin
            gunicorn --access-logfile - -w 2 --worker-class=gevent cronq.web:app
        
            # access the panel on http://127.0.0.1:8000
        
        The web admin will list available commands, their result history, and a button to allow you to immediately schedule a job.
        
        Categories Api
        ==============
        
        The web admin exposes a ``category`` endpoint which allows you to replace a set of jobs with a single API call
        
        .. code-block:: bash
        
            curl -v 'localhost:5000/api/category/example' -f -XPUT -H 'content-type: application/json' -d '
            {
                "category": "example",
                "jobs": [{
                    "name": "Test Job",
                    "schedule": "R/2013-05-29T00:00:00/PT1M",
                    "command": "sleep 10",
                    "routing_key": "slow"
                }]
            }'
        
        This adds / updates a job named ``Test Job`` in the ``example`` category. The time format is ISO 8601. Any jobs no longer defined for the example category will be removed. This allows you to script job additions / removes in your VCS.
        
        
        License
        =======
        
        BSD
        
        .. _SeatGeek: https://seatgeek.com
        
Keywords: cron amqp
Platform: UNKNOWN
