Kept on disk it was the take's fallback; once the mesh's interface is up in its place and a peer
has handshaken with it, it is an unmaintained way back onto the network, held for ever. It is now
removed from where its unit reads it, its kept original verified first and left as it is, and the
hold ends. Until proven — no handshake, or wg not answering — it is kept and the report says why.
The retirement is recorded apart from holds, so later applies, an undeclare, and a reassignment
find it retired rather than missing, and nothing writes it back.
Review of the ADR 0105 build (hq ADR 0105). The takeover stopped the found
unit and then found out whether the mesh's interface would do; a start that
failed left the machine with no tunnel at all.
Now nothing is stopped until the declared interface listens on the found port
at the found address and the key file it names holds the found key — the
refusal names the remedy — and a mesh interface that fails to start after the
takeover has the found unit started again, with the account saying so. The
account has three states (not taken, taken, down) and is given on every
takeover, failure included. An interface raised by hand is looked at again
for a moment and then refused naming `wg-quick down`. A found unit started
again by hand beside the mesh's is said, not stopped: on the hub it cannot
hold the port, and on a spoke two interfaces with one key would fight.
`mesh-host overlay take --tunnel <iface>` is the path for a node that
enrolled before the mesh knew to take a tunnel over: the found key becomes its
overlay key — identity, sealing and serving keys untouched, so nothing sealed
to the node is remade — and the mesh is told with a rekey signed by the
identity key, over the key left, the key taken and the tunnel. Told first,
written second, so a run again puts right whichever half did not happen.
On an adopted machine the private network takes the predecessor's tunnel
over in place (hq ADR 0105). Genesis finds the one interface up besides the
mesh's own, settles the hub's port and the mesh's range on it, and skips
ADR 0100's non-overlap check for a range that is now the tunnel's; a
--hub-port or --overlay-range that disagrees is refused naming the tunnel's.
At enrolment the found interface's private key becomes this node's overlay
key — the one credential the mesh takes rather than mints — stored where a
generated one is stored, never printed and never sent; the tunnel (port,
address, range, peers) travels with the keys so the mesh composes from it
before the first declaration.
The interface's service may say what it takes over. Before the mesh's unit
starts, the found configuration is kept like any held file and the found
unit is stopped and disabled; nothing is flushed, and an interface still up
after its unit stopped refuses the takeover rather than half-working. The
report says what was carried: interface, port, range, peer count, taken or
not, and where the original was kept.
jochen
jschoubben