When traffic steering is enabled, some users are suggested an exit
node that is inappropriately far from their location. This seems to
happen right when the client connects to the control plane and the
client eventually fixes itself. But whenever an affected client
reconnects, its suggested exit node flaps, and this happens often
enough to be noticeable because connections drop whenever the exit
node is switched. This should not happen, since the map response that
contains the list of suggested exit nodes that the client picks from,
also contains the scores for those nodes.
Since our current logging and diagnostic tools don’t give us enough
insight into what is happening, this PR adds additional logging when:
- traffic steering scores are used to suggest an exit node
- an exit node is suggested, no matter how it was determined
Updates: tailscale/corp#29964
Updates: tailscale/corp#36446
Signed-off-by: Simon Law <sfllaw@tailscale.com>
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