This change is to make JSONHandler error handling intuitive, as before there would be two sources of HTTP status code when HTTPErrors were generated: one as the first return value of the handler function, and one nested inside the HTTPError. Previously, it took the first return value as the status code, and ignored the code inside the HTTPError. Now, it should expect the first return value to be 0 if there is an error, and it takes the status code of the HTTPError to set as the response code.
Signed-off-by: Daniel Chung <daniel@tailscale.com>
This lets servers using tsweb register expvars
that will track the number of requests ending
in 200s/300s/400s/500s.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
There's often some useful piece of information in there not already
repeated in the internal error.
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
The name's been bugging me for a long time.
I liked neither the overlap between tsweb.Handler and http.Handler,
nor the name "ServeHTTPErr" which sounds like it's an error being
returned, like it's an error handler and not sometimes a happy path.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It's technically weird to return a tsweb.Error with no child err,
but it's a sensible thing to want to do, and we shouldn't panic
if it happens.
Signed-off-by: David Anderson <dave@natulte.net>
Handler is like http.Handler, but returns errors. ErrHandler
converts back to an http.Handler, with added error handling
and logging.
Signed-off-by: David Anderson <dave@natulte.net>
Basically, don't trust the OS-level link monitor to only tell you
interesting things. Sanity check it.
Also, move the interfaces package into the net directory now that we
have it.
This lets us publish sets of vars that are breakdowns along one
dimension in a format that Prometheus and Grafana natively know
how to do useful things with.
Signed-off-by: David Anderson <dave@natulte.net>