Quantum

Cron-like job scheduler for Elixir.

Setup

To use Quantum in your projects, edit your mix.exs file and add Quantum as a dependency:

defp deps do
  [{:quantum, ">= 1.3.0"}]
end

Then, add Quantum to the list of applications in your mix.exs file:

def application do
  [applications: [:quantum]]
end

Usage

Configure your cronjobs in your config/config.exs like this:

config :quantum, cron: [
    # Every minute
    "* * * * *":      {"Heartbeat", :send},
    # Every 15 minutes
    "*/15 * * * *":   fn -> System.cmd("rm", ["/tmp/tmp_"] end,
    # Runs on 18, 20, 22, 0, 2, 4, 6:
    "0 18-6/2 * * *": fn -> :mnesia.backup('/var/backup/mnesia') end,
    # Runs every midnight:
    "@daily":         &Backup.backup/0
]

Or you can use cron-like format (useful with conform/exrm):

config :quantum, cron: [
    # Every minute
    "* * * * * MyApp.MyModule.my_method"
]

If you want to add jobs on runtime, this is possible, too:

Quantum.add_job("1 * * * *", fn -> :ok end)

Crontab format

field          allowed values
-----          --------------
minute         0-59
hour           0-23
day of month   1-31
month          1-12 (or names)
day of week    0-6 (0 is Sunday, or use names)

Names can also be used for the month and day of week fields. Use the first three letters of the particular day or month (case does not matter).

Note: all times are defined in UTC and not in local time. Make sure you remember that when you run in your dev environment and wonder why your crons are not firing.

Special expressions

Instead of the first five fields, one of these special strings may be used:

string      description
------      -----------
@annually   Run once a year, same as "0 0 1 1 *" or @yearly
@daily      Run once a day, same as "0 0 * * *" or @midnight
@hourly     Run once an hour, same as "0 * * * *"
@midnight   Run once a day, same as "0 0 * * *" or @daily
@monthly    Run once a month, same as "0 0 1 * *"
@reboot     Run once, at startup
@weekly     Run once a week, same as "0 0 * * 0"
@yearly     Run once a year, same as "0 0 1 1 *" or @annually

Contribution

This project uses the C4.1 process for all code changes.

“Everyone, without distinction or discrimination, SHALL have an equal right to become a Contributor under the terms of this contract.”

tl;dr

1. Check for open issues or open a new issue to start a discussion around a problem.
2. Issues SHALL be named as “Problem: description of the problem“.
3. Fork the quantum-elixir repository on Github to start making your changes
4. If possible, write a test which shows that the problem was solved.
5. Send a pull request.
6. Pull requests SHALL be named as “Solution: description of your solution“
7. Your pull request is merged and you are added to the list of contributors

License

Apache License, Version 2.0