Knowing why a relay server failed to join the pool can be important. This
is typically an issue which must be investigated after it occurred, so
having logs available is useful.
Running with -debug permanently enabled is impractical, due to the amount
of traffic that is generated, particularly when data is being transferred.
Logging is limited to at most one message per minute, although one message
per hour is more likely.
This allows relaysrv to listen on an unprivileged port, with port
forwarding directing traffic from 443, thus providing an alternative
to using setcap cap_net_bind_service=+ep
We're going to need the db.Instance to keep some state, and for that to
work we need the same one passed around everywhere. Hence this moves the
leveldb-specific file opening stuff into the db package and exports the
dbInstance type.
'AlwaysLocalNets' was getting printed, but was getting used
when setting up connections. Now, the nets that should be
considered local are printed and used.
Overwriting configuration files is likely to happen if a
user syncs their home directories across computers. In this
case, the biggest risk is that all nodes will end up with
the same certificate and thus Device ID.
When the model prepares a folder for syncing, it checks to
see if the configuration files this instance is using are
getting synced. If the are getting synced, and they aren't
getting ignored, a warning is emitted. The model is used
so that when a new folder is added dynamically, a warning
is also emitted.
This will not prevent a user from shooting themselves in
the foot, and will not cover all cases (e.g. symlinks).
It should provide _something_ for many users in this
situation to go on, though.
