bronger / watchdog

Purpose

The watchdog watches changes in a directory recursively, and synchronises these changes with remote sites.

Alternatives

sshfs

This has possibly slow operations, shadows the local directory structure, and cannot synchronise with more than one remote.

inotifywait + rsync

This is slow with large directories

Call signature

You call the watchdog with:

watchdog <configuration-directory>

Configuration file

The configuration directory must contain a file confguration.yaml which may look like this:

current dir: /home/bronger
watched dirs:
  - root: Mail
    agglomeration ms: 100
    excludes:
      - ^Mail/\.#active
      - ^Mail/active
      - /\.overview
      - /\.#\.overview

current dir should be an absolute path. Each root is relative to current dir. The excludes are Go-style (non-POSIX) regular expressions.

agglomeration ms is 10 by default and denotes the milliseconds to wait after a change for further changes. Those are then processed with a minimal number of calls of the synchronisation scripts.

Synchronisation scripts

We need the following three programs: bulk_sync, copy, and delete. They must be executables in <configuration-directory>. There are example scripts in this repository.

The single argument passed to the scripts is relative to current dir from the configuration.

The scripts should exit quickly and gracefully when they receive a SIGTERM.

bulk_rsync

This synchronises its argument – which may be a file or a directory – with the remote. It must make sure that files and direcories on the remote missing locally are deleted remotely.

copy

This copy its argument – a file – to the remote.

delete

This deletes its argument – which may be a file or a directory – from the remote.