Advanced cron scheduler written in Golang and compatible with Linux and Mac.
Advantages
- Compatible with legacy cron files
- Ability to create tasks for every second, not minute as default
- Ability to log output for each job individually
- Ability to choose different shell for each job
- Ability to set a timezone for the specific task and default for all
- Ability to set user for all jobs together
- Outputs execution time to stdout
- Errors can be logged into Sentry
You can use legacy cron configuration file (https://linuxconfig.org/linux-crontab-reference-guide) or use new style config below.
By default daemon looking for config in the current directory. To change that you can use -config and -path flags.
Configuration is set via config file written in JSON, TOML, YAML, HCL, and Java properties. By default daemon looking for config.* in the current directory. To change that you can use -config (filename w/o extension) and -path flags.
Example of configuration in YAML: config.example.yaml
| Field name | Mandatory? | Allowed values | Allowed special characters |
|---|---|---|---|
| Seconds | No | 0-59 | * / , - |
| Minutes | Yes | 0-59 | * / , - |
| Hours | Yes | 0-23 | * / , - |
| Day of month | Yes | 1-31 | * / , - ? |
| Month | Yes | 1-12 or JAN-DEC | * / , - |
| Day of week | Yes | 0-6 or SUN-SAT | * / , - ? |
Asterisk ( * )
The asterisk indicates that the cron expression will match for all values of the field; e.g., using an asterisk in the 5th field (month) would indicate every month.
Slash ( / )
Slashes are used to describe increments of ranges. For example 3-59/15 in the 1st field (minutes) would indicate the 3rd minute of the hour and every 15 minutes thereafter. The form "*/..." is equivalent to the form "first-last/...", that is, an increment over the largest possible range of the field. The form "N/..." is accepted as meaning "N-MAX/...", that is, starting at N, use the increment until the end of that specific range. It does not wrap around.
Comma ( , )
Commas are used to separate items of a list. For example, using "MON,WED,FRI" in the 5th field (day of week) would mean Mondays, Wednesdays and Fridays.
Hyphen ( - )
Hyphens are used to define ranges. For example, 9-17 would indicate every hour between 9am and 5pm inclusive.
Question mark ( ? )
Question mark may be used instead of '*' for leaving either day-of-month or day-of-week blank.
| Entry | Description | Equivalent To |
|---|---|---|
| @reboot | Run once after config load/reload | |
| @yearly (or @annually) | Run once a year, midnight, Jan. 1st | 0 0 0 1 1 * |
| @monthly | Run once a month, midnight, first of month | 0 0 0 1 * * |
| @weekly | Run once a week, midnight on Sunday | 0 0 0 * * 0 |
| @daily (or @midnight) | Run once a day, midnight | 0 0 0 * * * |
| @hourly | Run once an hour, beginning of hour | 0 0 * * * * |
@every duration
For example, "@every 1h30m10s" would indicate a schedule that activates every 1 hour, 30 minutes, 10 seconds.
@once time
For example, "@once @every 1h" would indicate a schedule that job need to be run 1 time 1 hour after config load/reload.
You can set time in all formats described above, excluding @reboot.
Few examples:
@once 1 * * * *
@once @montly
@once @every 1d
By default, all interpretation and scheduling is done in the machine's local time zone (as provided by the Go time package http://www.golang.org/pkg/time). The time zone may be overridden by providing an additional space-separated field at the beginning of the cron spec, of the form "TZ=Asia/Tokyo"
Be aware that jobs scheduled during daylight-savings leap-ahead transitions will not be run!
Scheduler is based on https://github.com/robfig/cron (additional functionality added).