This allows each probe to easily export gauge metrics with consistent
naming scheme without integrating with expvar directly.
Note that it's a backwards incompatible change to ProbeFunc. Given
minimal usage of this module I don't think this is problematic, but I
can add a separate function here if you would prefer that.
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
TLS prober now checks validity period for all server certificates
and verifies OCSP revocation status for the leaf cert.
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
Anton Tolchanov