mon for Mac

mon(1)

Super-simple monitoring program.

mon spawned from the needlessly complex frustration that tools like monit provide, with their awkward DSLs and setup. mon is written in C, uses less than 400kb of memory, and is incredibly simple to set up.

Installation

Too lazy to clone?:

Usage

Example

The most simple use of mon(1) is to simply keep a command running:

You may daemonize mon and disassociate from the term with -d:

Failure alerts

mon(1) will continue to attempt restarting your program unless the maximum number of --attempts has been exceeded within 60 seconds. Each time a restart is performed the --on-restart command is executed, and when mon(1) finally bails the --on-error command is then executed before mon itself exits and gives up.

For example the following will echo "hey" three times before mon realizes that the program is unstable, since it's exiting immediately, thus finally invoking ./email.sh, or any other script you like.

__NOTE__: The process id is passed as an argument to both --on-error and --on-restart scripts.

Managing several mon(1) processes

mon(1) is designed to monitor a single program only, this means a few things, firstly that a single mon(1) may crash and it will not influence other programs, secondly that the "configuration" for mon(1) is simply a shell script, no need for funky weird inflexible DSLs.

I highly recommend checking out jgallen23's mongroup(1), which provides a great interface for managing any number of mon(1) instances.

Logs

By default mon(1) logs to stdio, however when daemonized it will default to writing a log file named ./mon.log. If you have several instances you may wish to --prefix the log lines, or specify separate files.

Signals __SIGQUIT__ graceful shutdown __SIGTERM__ graceful shutdown

Links

Tools built with mon(1): mongroup(1) - monitor a group of processes (shell script) node-mongroup - node implementation of mongroup(1)

License

MIT

Build Status