This is causing problems with certain servers that have a lot of open
FDs; the process collector that Prometheus provides generates a lot of
garbage when enumerating open FDs, which is why we have
metrics.CurrentFDs (which uses util/dirwalk).
Updates tailscale/corp#19900
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I732f854e637c4d7a651b3c74cd8e363cb1092bcc
This splits Prometheus metric handlers exposed by tsweb into two
modules:
- `varz.Handler` exposes Prometheus metrics generated by our expvar
converter;
- `promvarz.Handler` combines our expvar-converted metrics and native
Prometheus metrics.
By default, tsweb will use the promvarz handler, however users can keep
using only the expvar converter. Specifically, `tailscaled` now uses
`varz.Handler` explicitly, which avoids a dependency on the
(heavyweight) Prometheus client.
Updates https://github.com/tailscale/corp/issues/10205
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
