This adds @alexwlchan's proposed "tailscale get" command that reads
current preference values, complementing "tailscale set". It uses the
same flag names as set.
tailscale get # show all settings as a table
tailscale get all # same
tailscale get accept-dns # show a single value
tailscale get --json # output as JSON object
tailscale get --set-flags # output as tailscale set argv
Fixes#11389Fixestailscale/corp#38702
Change-Id: Ie366f27f11ccc56c76fff9a94ed8a9de9c835bd0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
b7860f2b5f