Expand description
Keep the host’s network managers from touching overlay interfaces.
systemd-networkd (and NetworkManager) with a permissive default match
will try to MANAGE a freshly-created overlay link (zl-*, veth-*) — bring it
up, run DHCP / IPv6 autoconf, and (observed on a CI runner) hit the
3-minute systemd-networkd watchdog and SIGABRT while processing a zl-*
Link UP. overlayd configures these links itself via netlink, so we drop a
tiny “Unmanaged” config for each manager that is present.
Best-effort + idempotent: a manager’s drop-in is only written when that
manager’s runtime dir exists, every error is logged (never fatal), and the
manager is reloaded so it re-evaluates already-created links. Root-mode only
(rootless overlay creates no host zl-* links — pasta handles egress);
a pure no-op on non-Linux.
Functions§
- mark_
overlay_ interfaces_ unmanaged - Install drop-ins telling
systemd-networkdandNetworkManagerto leavezl-*/veth-*overlay interfaces unmanaged. Best-effort, idempotent, root-mode only. No-op on non-Linux. - unmark_
overlay_ interfaces_ unmanaged - Remove the unmanaged drop-ins (clean reversion on overlay teardown). Best-effort, idempotent. No-op on non-Linux.