https://github.com/jbox-web/crono
Crono is a time-based background job scheduler daemon (just like Cron) for Ruby on Rails.
https://github.com/jbox-web/crono
cron crontab job-crono rails ruby
Last synced: 8 months ago
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Crono is a time-based background job scheduler daemon (just like Cron) for Ruby on Rails.
- Host: GitHub
- URL: https://github.com/jbox-web/crono
- Owner: jbox-web
- License: apache-2.0
- Created: 2020-04-05T02:03:21.000Z (about 6 years ago)
- Default Branch: master
- Last Pushed: 2025-07-01T23:59:37.000Z (12 months ago)
- Last Synced: 2025-07-02T00:29:34.397Z (12 months ago)
- Topics: cron, crontab, job-crono, rails, ruby
- Language: Ruby
- Homepage:
- Size: 1.67 MB
- Stars: 4
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# Crono - Job scheduler for Rails
[](https://github.com/jbox-web/crono/blob/master/LICENSE)
[](https://github.com/jbox-web/crono/releases/latest)
[](https://github.com/jbox-web/crono/actions)
[](https://codeclimate.com/github/jbox-web/crono)
[](https://codeclimate.com/github/jbox-web/crono/coverage)
Crono is a time-based background job scheduler daemon (just like Cron) for Ruby on Rails.
## The Purpose
Currently, there is no such thing as Ruby Cron for Rails.
Well, there's [Whenever](https://github.com/javan/whenever) but it works on top of Unix Cron, so you can't manage it from Ruby.
Crono is pure Ruby. It doesn't use Unix Cron and other platform-dependent things. So you can use it on all platforms supported by Ruby.
It persists job states to your database using Active Record. You have full control of jobs performing process.
It's Ruby, so you can understand and modify it to fit your needs.
## Requirements
Tested with latest MRI Ruby 2.5+, 2.6+, 2.7+, Rails 5.\*, and Rails 6.\*.
Other versions are untested but might work fine.
## Installation
Add the following line to your application's Gemfile:
```ruby
gem 'crono'
```
Run the `bundle` command to install it.
After you install Crono, you can run the generator:
```sh
bin/rails generate crono:install
```
It will create a configuration file `config/cronotab.rb` and migration
Run the migration:
```sh
bin/rails db:migrate
```
Now you are ready to move forward to create a job and schedule it.
## Usage
#### Create Job
Crono can use Active Job jobs from `app/jobs/`. The only requirement is that the `perform` method should take no arguments.
Here's an example of a job:
```ruby
# app/jobs/test_job.rb
class TestJob < ActiveJob::Base
def perform
# put you scheduled code here
# Comments.deleted.clean_up...
end
end
```
The ActiveJob jobs are convenient because you can use one job in both periodic and enqueued ways. But Active Job is not required. Any class can be used as a crono job if it implements a method `perform`:
```ruby
class TestJob # This is not an Active Job job, but pretty legal Crono job.
def perform(*args)
# put you scheduled code here
# Comments.deleted.clean_up...
end
end
```
Here's an example of a Rake Task within a job:
```ruby
# config/cronotab.rb
require 'rake'
Rails.app_class.load_tasks
class Test
def perform
Rake::Task['crono:hello'].invoke
end
end
Crono.perform(Test).every 5.seconds
```
With the rake task of:
```ruby
# lib/tasks/test.rake
namespace :crono do
desc 'Update all tables'
task :hello => :environment do
puts "hello"
end
end
```
_Please note that crono uses threads, so your code should be thread-safe_
#### Job Schedule
Schedule list is defined in the file `config/cronotab.rb`, that created using `crono:install`. The semantic is pretty straightforward:
```ruby
# config/cronotab.rb
Crono.perform(TestJob).every 2.days, at: { hour: 15, min: 30 }
Crono.perform(TestJob).every 1.week, on: :monday, at: "15:30"
```
You can schedule one job a few times if you want the job to be performed a few times a day or a week:
```ruby
Crono.perform(TestJob).every 1.week, on: :monday
Crono.perform(TestJob).every 1.week, on: :thursday
```
The `at` can be a Hash:
```ruby
Crono.perform(TestJob).every 1.day, at: { hour: 12, min: 15 }
```
You can schedule a job with arguments, which can contain objects that can be
serialized using JSON.generate
```ruby
Crono.perform(TestJob, 'some', 'args').every 1.day, at: { hour: 12, min: 15 }
```
You can set some options that not passed to the job but affect how the job will be treated by Crono. For example, you can set to truncate job logs (which stored in the database) to a certain number of records:
```ruby
Crono.perform(TestJob).with_options(truncate_log: 100).every 1.week, on: :monday
```
#### Run
To run Crono, first add it to your project as a binstub :
In your Rails project root directory:
```sh
bundle binstubs crono
```
then :
```sh
bin/crono --help
```
crono usage:
```sh
Usage: crono [options]
-C, --cronotab PATH Path to cronotab file (Default: config/cronotab.rb)
-e, --environment ENV Application environment (Default: development)
```
#### Run as a daemon
To run Crono as a daemon, please use systemd or supervisor.
* [systemd config sample](https://github.com/jbox-web/crono/blob/master/examples/systemd/crono.service)
* [monit config sample](https://github.com/jbox-web/crono/blob/master/examples/monit/monitrc.conf)
## Web UI
Crono comes with a Sinatra application that can display the current state of Crono jobs.
Add `sinatra` and `haml` to your Gemfile
```ruby
gem 'haml'
gem 'sinatra', require: nil
```
Add the following to your `config/routes.rb`:
```ruby
Rails.application.routes.draw do
mount Crono::Web, at: '/crono'
...
end
```
Access management and other questions described in the [wiki](https://github.com/plashchynski/crono/wiki/Web-UI).
#### Known issues
For Rails 5, in case of the errors:
```ruby
`require': cannot load such file -- rack/showexceptions (LoadError)
```
See the related issue [#52](https://github.com/plashchynski/crono/issues/52)
## Capistrano
Use the `capistrano-crono` gem ([github](https://github.com/plashchynski/capistrano-crono/)).
## Support
Feel free to create [issues](https://github.com/jbox-web/crono/issues)
## Known Issues
* Is not compatible with the `protected_attributes` gem. See: [#43](https://github.com/plashchynski/crono/issues/43)
## License
Please see [LICENSE](https://github.com/jbox-web/crono/blob/master/LICENSE) for licensing details.