This patch changes that the script will listen to changes to the directory instead of the file which got complicated when files got renamed.

It also processes all changes at the same time and tries finding out what actions have to be performed in order to avoid unnecessary iterations.

The script is also limited to process any changes only once every five seconds to keep resource usage in check on busy systems.

Suggested-by: Anthony Heading ajrh@ajrh.net Signed-off-by: Michael Tremer michael.tremer@ipfire.org --- config/unbound/unbound-dhcp-leases-bridge | 70 +++++++++++++++-------- 1 file changed, 47 insertions(+), 23 deletions(-)

diff --git a/config/unbound/unbound-dhcp-leases-bridge b/config/unbound/unbound-dhcp-leases-bridge index ce0cb8614..c0e5977bf 100644 --- a/config/unbound/unbound-dhcp-leases-bridge +++ b/config/unbound/unbound-dhcp-leases-bridge @@ -32,6 +32,7 @@ import stat import subprocess import sys import tempfile +import time

import inotify.adapters

@@ -82,6 +83,12 @@ class UnboundDHCPLeasesBridge(object): self.fix_leases_file = fix_leases_file self.hosts_file = hosts_file

+ self.watches = { + self.leases_file : inotify.constants.IN_MODIFY, + self.fix_leases_file : 0, + self.hosts_file : 0, + } + self.unbound = UnboundConfigWriter(unbound_leases_file) self.running = False

@@ -89,37 +96,54 @@ class UnboundDHCPLeasesBridge(object): log.info("Unbound DHCP Leases Bridge started on %s" % self.leases_file) self.running = True

- # Initial setup - self.hosts = self.read_static_hosts() - self.update_dhcp_leases() + i = inotify.adapters.Inotify()

- i = inotify.adapters.Inotify([ - self.leases_file, - self.fix_leases_file, - self.hosts_file, - ]) + # Add watches for the directories of every relevant file + for f, mask in self.watches.items(): + i.add_watch( + os.path.dirname(f), + mask | inotify.constants.IN_CLOSE_WRITE | inotify.constants.IN_MOVED_TO, + )

- for event in i.event_gen(): - # End if we are requested to terminate - if not self.running: - break + # Enabled so that we update hosts and leases on startup + update_hosts = update_leases = True

- if event is None: - continue + while self.running: + log.debug("Wakeup of main loop") + + # Process the entire inotify queue and identify what we need to do + for event in i.event_gen(): + # Nothing to do + if event is None: + break + + # Decode the event + header, type_names, path, filename = event

- header, type_names, watch_path, filename = event + file = os.path.join(path, filename)

- # Update leases after leases file has been modified - if "IN_MODIFY" in type_names: - # Reload hosts - if watch_path == self.hosts_file: - self.hosts = self.read_static_hosts() + log.debug("inotify event received for %s: %s", file, " ".join(type_names))

+ # Did the hosts file change? + if self.hosts_file == file: + update_hosts = True + + # We will need to update the leases on any change + update_leases = True + + # Update hosts (if needed) + if update_hosts: + self.hosts = self.read_static_hosts() + + # Update leases (if needed) + if update_leases: self.update_dhcp_leases()

- # If the file is deleted, we re-add the watcher - if "IN_IGNORED" in type_names: - i.add_watch(watch_path) + # Reset + update_hosts = update_leases = False + + # Wait a moment before we start the next iteration + time.sleep(5)

log.info("Unbound DHCP Leases Bridge terminated")