inotify-base

A slim and customisable container image designed for quick and easy script hooks on file changes.

This can be used as a sidecar container in Kubernetes/Docker/container based applications to trigger certain HTTP webhook/other commands upon a change to a mounted file/folder.

Configuration

Variable	Description	Default
INOTIFY_HOOK_SCRIPT	The executable to run on a change, as a path mounted on the filesystem	None
INOTIFY_WATCH_EVENTS	The types of events to listen for as a comma separated list, for example delete,move. A full list of events is available on the inotifywait manpage	All events
INOTIFY_WATCH_DIRECTORY	The directory to watch for changes in, all subdirectories are recursively watched.	/opt/monitor
INOTIFY_HOOK_DELAY	A delay (in seconds) to wait before executing a hook, also acts as a debounce cooldown to prevent multiple events within a timespan	No delay

It is recommended to mount your INOTIFY_HOOK_SCRIPT in a location that is not used by any other aspect of the container, for example, mounting to /opt/owl-corp/ and using /opt/owl-corp/hook.sh as your INOTIFY_HOOK_SCRIPT option.

Warning

By default, inotifywait will notify on all file events, this includes things like reading directories and opening files.

It is highly recommended to refer to the above mentioned inotifywait manpage for the full list of events to narrow down to those which only modify a file in the ways you specifically wish to observe.

Usage

A Docker compose file using this image might look like the following:

services:
  notifier:
    image: "ghcr.io/owl-corp/inotify-base:latest"
    volumes:
    - type: bind
      source: ./config
      target: /opt/monitor
    - type: bind
      source: ./scripts
      target: /opt/owl-corp
    environment:
      INOTIFY_HOOK_SCRIPT: /opt/owl-corp/script.sh

This will watch for all configuration changes in the local filesystem config directory and execute the script.sh file in the local scripts directory.

License

MIT License.