Add a vmtest that guards the fix in #20025: after an in-process control
client swap (profile switch / interactive re-login), magicsock's NetInfo
dedup cache (netInfoLast) must be cleared so the structurally-identical
post-switch NetInfo (same PreferredDERP, same NAT shape) is re-reported to
the new control session rather than suppressed as unchanged.
The test brings a node up, pins its home DERP so the reported NetInfo is
identical across the switch, records the home DERP the test control learned,
switches to a fresh login profile on the same control/network/NAT/DERP, and
asserts the control re-learns the same non-zero home DERP for the node's new
identity. Without ResetNetInfoLast the assertion times out at HomeDERP=0.
To support this, vnet now serves the test control on port 443 (TLS) in
addition to port 80: an immediate re-login makes a fresh noise dial, and
because the prior dial was recent the control client forces an HTTPS (443)
dial (controlhttp.Dialer.forceNoise443), which the harness previously did
not answer. The control endpoint gets its own self-signed cert (the existing
selfSignedDERPCert helper, renamed to the generic selfSignedCert); the cert
is not validated since control noise dials authenticate via the Noise
handshake, so it only needs a TLS peer to complete the forced 443 dial.
Add Env.ForcePreferredDERP and Env.Relogin helpers for the above.
Updates #20024
Signed-off-by: Mike O'Driscoll <mikeo@tailscale.com>
Mike O'DriscollandGitHub
732bde6e86