# README

cronlock-go

Distributed cron lock written in go with a UI for visualizing current crons and their status.

But why?

Features:

run multiple cron servers for high availability
easily perform maintenance on cron hosts without missing crons
expose metrics like how many crons are running, their pass/fail statuses, and duration

Install Redis

You must have a running Redis server for cronlock to work.

MacOS:

brew install redis

Start the redis server:

brew services start redis

Stop the redis server:

brew services stop redis

Build

Generate the cronlock and cronlockweb binaries.

make

Run a command

Without cron:

./cronlock sleep 60

With cron:

* * * * * cronlock sleep 60

Start the web UI

make web

Templates

HTML templates (cmd/cronlockweb/templates) should be placed in the working directory of cronlockweb.

Configuration

Any of these options can be passed to cronlock per command or set as global environment variables.

CRONLOCK_REDIS_HOST - (default: localhost) hostname or IP address of the Redis server

CRONLOCK_REDIS_PORT - (default: 6379) port Redis is running on

CRONLOCK_TIMEOUT- (default: 3600) expire the cronlock after N seconds if it somehow fails to report success or failure. 0 creates permanent lock for crons with the same hash. useful to ensure a cron never gets ran more than once

CRONLOCK_GRACE_PERIOD - (default: 5 sec) remove lock N seconds after cron ends. useful for quick crons. must be greater than 0. When CRONLOCK_TIMEOUT is set to zero, this has no use

For debugging and more verbose feedback:

CRONLOCK_DEBUG - (default: false) show debug log lines

CRONLOCK_PRINT_STDOUT - (default: false) print stdout of command when executing cron

CRONLOCK_PRINT_ARGS - (default: false) print the script arguments when executing cron