slackhq_nebula/LOGGING.md

Logging conventions

A log message (the string/format passed to Info, Error, Debug etc, as well as their Sprintf counterparts) should be a descriptive message about the event and may contain specific identifying characteristics. Regardless of the level of detail in the message identifying characteristics should always be included via WithField, WithFields or WithError

If an error is being logged use l.WithError(err) so that there is better discoverability about the event as well as the specific error condition.

Common fields

• cert - a cert.NebulaCertificate object, do not .String() this manually, logrus will marshal objects properly for the formatter it is using.
• fingerprint - a single NebeulaCertificate hex encoded fingerprint
• fingerprints - an array of NebulaCertificate hex encoded fingerprints
• fwPacket - a FirewallPacket object
• handshake - an object containing:
  • stage - the current stage counter
  • style - noise handshake style ix_psk0, xx, etc
• header - a nebula header object
• udpAddr - a net.UDPAddr object
• udpIp - a udp ip address
• vpnIp - vpn ip of the host (remote or local)
• relay - the vpnIp of the relay host that is or should be handling the relay packet
• relayFrom - The vpnIp of the initial sender of the relayed packet
• relayTo - The vpnIp of the final destination of a relayed packet

Example:

l.WithError(err).
    WithField("vpnIp", IntIp(hostinfo.hostId)).
    WithField("udpAddr", addr).
    WithField("handshake", m{"stage": 1, "style": "ix"}).
    Info("Invalid certificate from host")