Until now a membership — bus address, fingerprint, password — was written once,
at enrolment, and nothing ever rewrote it, so a machine already enrolled could not
be moved to another bus at all (novox/hq design 28, task 5.2). The mesh now
delivers a membership for the new bus as a sealed file in the declaration, like
any secret; the host reads it after the declaration has applied, saves it as its
identity, and exits cleanly so the service manager restarts it dialling the bus it
names. The same path a machine takes after a reboot — so nothing new has to be
right for it to work. A membership carries its transport; empty means the bus the
mesh ran on before, so nothing written earlier reads as unset.
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.
Curve25519, which is what WireGuard uses. The private half never leaves the
machine and is written to a file of its own, so the interface configuration the
mesh composes can point at it without ever carrying it.
Separate from the identity keypair on purpose. One signs messages to the mesh
and the other encrypts traffic between nodes -- different things verified by
different parties at different times, and a key used for two purposes is one
rotation away from breaking the other.
Pushed a failing test in the last commit -- my own gate reported it and I read
the count rather than the result. The failure was real and worth having.
Adding the membership requirement to Load made Generate produce an identity that
Save would write and Load would then refuse. A file that cannot be read back is
the worst shape this could take: it is read back on the next start, on a machine
nobody is watching, and by then the token that could have fixed it is spent.
Save now refuses exactly what Load refuses, and writes nothing when it does. The
round-trip test covers the membership too, since that is the half that lets a
node come back on its own.
The loop the whole thing exists for: told, apply, report.
`run` holds one outbound connection open and consumes the node's own queue.
Every declaration is verified against the control plane's signing key before a
byte of it is read as an instruction -- not once at connect, every time. The
transport being pinned is a different question from the instruction being
genuine, and pinning only the first would make the second transitive: a
compromised broker could forge declarations, and this host applies whatever the
link delivers.
Malformed and forged are reported differently, because ADR 0004 requires a host
to tell "this is not from the mesh I joined" from "this is broken". One means
somebody is trying and the other means something needs fixing.
A node now keeps what it needs to come back on its own: the broker's address
and fingerprint, the signing key it believes, and its own broker password --
which the mesh issues at enrolment to replace the token's secret, so the
one-time thing stays one-time and the credential it holds for years is not the
one that was pasted into a terminal.
Verified in the lab end to end. The node enrolled, held its link, received a
signed declaration and applied it -- the file is on the machine with the right
contents, and the host's own record lists both resources.
That run also found issue 010, which is recorded in novox/hq: the declaration
removed every container on the machine, including the control plane that sent
it. Correct reconciliation, shared store, and the first thing that happens.
The host side of enrolment. It parses a token the control plane issued, dials
the broker, refuses anything but the pinned certificate, and generates an
Ed25519 keypair whose private half never leaves the machine.
Verified against a real LavinMQ serving a real certificate: the pin matched and
the node proceeded. Then against a second broker with a different certificate
on another port, which was refused -- with an error that says retrying will not
help, because it does not mean the network is down, it means the mesh was
substituted.
InsecureSkipVerify is set and that is the point rather than a weakening. At
bootstrap the broker is self-signed and reached at an address, so there is no
authority to trace and no name to match. Chain and hostname checks are replaced
with something stricter: this exact certificate or nothing, checked in
VerifyPeerCertificate, which runs before the handshake completes -- so nothing
is sent to the wrong broker. There is a test that counts the bytes an impostor
receives, and it is zero.
The token format is defined separately here and in the control plane, because
this binary requires nothing present and does not import it. They are held
together by a test on each side asserting the exact field names, so a rename
breaks both immediately rather than at enrolment on a real machine.
Two distinctions the identity file has to keep. A machine that never joined has
no identity, which is an ordinary state and not a fault. A machine whose
identity cannot be read is a different thing entirely, and must not take the
same path -- re-enrolling would discard the identity the mesh still believes and
need a person with a new token. Fault injection found the second case untested:
the corrupt-file test was passing on the parse check, so the read-error path had
nothing defending it. It does now.
An already-enrolled machine refuses to enrol again rather than quietly
acquiring a second identity.
What is not built is the link. Enrolment stops after verifying the broker and
generating the identity, having saved nothing, so it can be run again unchanged.
132 tests, plus 32 launcher and 9 rollback.
jschoubben