feat(dnsmasq): add --conf-poll feature and upgrade to Debian forky#2136
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skrobul wants to merge 1 commit into
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feat(dnsmasq): add --conf-poll feature and upgrade to Debian forky#2136skrobul wants to merge 1 commit into
skrobul wants to merge 1 commit into
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Bump the dnsmasq container to debian:forky-20260623-slim (dnsmasq 2.93-1), which is close enough to our dev tree that both vendored patches now apply cleanly, and rebase dhcp-allowed-srvids.patch onto that version. Add conf-poll.patch, a new dnsmasq feature (--conf-poll / --conf-poll-interval=<seconds>, default 1s) written to solve a real problem in our Ironic setup: dnsmasq relies on inotify to notice changes to --hostsdir, --dhcp-hostsdir and --dhcp-optsdir. When those directories live on an NFS share and are modified or created by a different NFS client (i.e. not the machine running dnsmasq itself), the local kernel never gets an inotify event for it, so dnsmasq silently keeps serving stale DNS/DHCP data until it's sent a SIGHUP or restarted. --conf-poll makes dnsmasq additionally stat() those directories on a timer (every --conf-poll-interval seconds) and reload anything that's new, changed, or removed, using the exact same reload logic as an inotify event or SIGHUP would trigger. It runs alongside inotify, not instead of it, so on non-NFS setups where inotify works fine it's just a harmless no-op backup check. It's opt-in and disabled by default, so existing deployments are unaffected unless the option is explicitly set. Deleting a file from --dhcp-hostsdir/--dhcp-optsdir intentionally still does not remove the DHCP config it added, since that already matches how those two options have always behaved.
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Bump the dnsmasq container to
debian:forky-20260623-slim(dnsmasq 2.93-1), which is close enough to our dev tree that both vendored patches now apply cleanly, and rebase dhcp-allowed-srvids.patch onto that version.Add conf-poll.patch, a new dnsmasq feature (
--conf-poll/--conf-poll-interval=<seconds>, default 1s) written to solve a real problem in our Ironic setup: dnsmasq relies oninotifyto notice changes to--hostsdir,--dhcp-hostsdirand--dhcp-optsdir. When those directories live on an NFS share and are modified or created by a different NFS client (i.e. not the machine running dnsmasq itself), the local kernel never gets an inotify event for it, so dnsmasq silently keeps serving stale DNS/DHCP data until it's sent a SIGHUP or restarted.--conf-pollmakes dnsmasq additionallystat()those directories on a timer (every--conf-poll-intervalseconds) and reload anything that's new, changed, or removed, using the exact same reload logic as an inotify event or SIGHUP would trigger. It runs alongside inotify, not instead of it, so on non-NFS setups where inotify works fine it's just a harmless no-op backup check. It's opt-in and disabled by default, so existing deployments are unaffected unless the option is explicitly set. Deleting a file from--dhcp-hostsdir/--dhcp-optsdirintentionally still does not remove the DHCP config it added, since that already matches how those two options have always behaved in stock dnsmasq.Related: https://rackspace.atlassian.net/browse/PUC-1729