A simple cron-like scheduler for a single command
Running a process in a Docker container on a fixed schedule is fiddly. Most solutions seem to involve installing cron, then installing a crontab and tailing cron's output. Yuck.
mantra is more like at, in that it allows you to specify the schedule as an argument in a cron format, along with the executable name and any arguments. It will then run that command, and only that command, on the schedule provided. STDOUT and STDERR are shared, making it easier to capture the program output.
Execute my_prog with some arguments at 1am every day:
mantra "0 1 * * * *" my_prog arg1 arg2
In your Dockerfile, download the latest binary, for example:
RUN curl -o /usr/local/bin/mantra -L https://github.com/pugnascotia/mantra/releases/download/0.0.1/mantra && \
chmod +x /usr/local/bin/mantra
Then call it:
CMD mantra schedule my_prog arg1 arg2 ...
Uses a slightly modified version of the excellent robfig/cron package.