DNS names consist of labels, but outside of length limits, DNS
itself permits any content within the labels. Some records require
labels to conform to hostname limitations (which is what we implemented
before), but not all.
Fixes#2024.
Signed-off-by: David Anderson <danderson@tailscale.com>
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
Consolidates the node display name logic from each of the clients into
tailcfg.Node. UI clients can use these names directly, rather than computing
them independently.
* show DNS name over hostname, removing domain's common MagicDNS suffix.
only show hostname if there's no DNS name.
but still show shared devices' MagicDNS FQDN.
* remove nerdy low-level details by default: endpoints, DERP relay,
public key. They're available in JSON mode still for those who need
them.
* only show endpoint or DERP relay when it's active with the goal of
making debugging easier. (so it's easier for users to understand
what's happening) The asterisks are gone.
* remove Tx/Rx numbers by default for idle peers; only show them when
there's traffic.
* include peers' owner login names
* add CLI option to not show peers (matching --self=true, --peers= also
defaults to true)
* sort by DNS/host name, not public key
* reorder columns
