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>
This provides an example of using native Prometheus metrics with tsweb.
Prober library seems to be the only user of PrometheusVar, so I am
removing support for it in tsweb.
Updates https://github.com/tailscale/corp/issues/10205
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
The handler will expose built-in process and Go metrics by default,
which currently duplicate some of the expvar-proxied metrics
(`goroutines` vs `go_goroutines`, `memstats` vs `go_memstats`), but as
long as their names are different, Prometheus server will just scrape
both.
This will change /debug/varz behaviour for most tsweb binaries, but
notably not for control, which configures a `tsweb.VarzHandler`
[explicitly](a5b5d5167f/cmd/tailcontrol/tailcontrol.go (L779))
Updates https://github.com/tailscale/corp/issues/10205
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
Ideally we should strip other invalid characters too, but that would
call for a regexp replacement which increases the number of allocations
and makes `TestVarzHandlerSorting` fail.
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
This removes the ~9 allocs added by #5869, while still keeping struct
fields sorted (the previous commit's tests still pass). And add a test
to lock it in that this shouldn't allocate.
Updates #5778
Change-Id: I4c12b9e2a1334adc1ea5aba1777681cb9fc18fbf
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This makes it easier to view prometheus metrics.
Added a test case which demonstrates the new behavior - the test
initially failed as the output was ordered in the same order
as the fields were declared in the struct (i.e. foo_a, bar_a, foo_b,
bar_b). For that reason, I also had to change an existing test case
to sort the fields in the new expected order.
Signed-off-by: Hasnain Lakhani <m.hasnain.lakhani@gmail.com>
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.
Reference: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
The Header field allows the server to specify specific headers to set.
Example use case: server returns 429 with the "Retry-After" header set.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
If the field is the zero value, then avoid serializing the field.
This reduces verbosity in server logs.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
We make assertions about stringification of 0.5. IEEE floating point and
all reasonable proprietary floating point can exactly represent 0.5.
We don't make assertions about other floating point values, too brittle
in tests.
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
Fixes the current http://pkgs.tailscale.com/ redirect to https:///
as that server doesn't configure the Port80Handler.FQDN field.
Change-Id: Iff56e6127a46c306ca97738d91b217bcab32a582
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It's unused and we've decided it's not what we want.
Change-Id: I425a0104e8869630b498a0adfd0f455876d6f92b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This enables the infrequent use of more complex Prometheus types, such as
timeseries with high/irregular label cardinality, without needing to
discover and implement generic abstracted type like LabelMap for each one.
Signed-off-by: David Anderson <danderson@tailscale.com>
When the request comes in say over http://mon, the current
implementation would rewrite it https://mon which causes the cert
validation to fail. This PR keeps the existing behavior intact but also
allows passing in a FQDN to the handler to reroute to the correct
hostname.
Related to https://github.com/tailscale/tailscale/pull/4208#pullrequestreview-913832340
Signed-off-by: Maisem Ali <maisem@tailscale.com>
A new package can also later record/report which knobs are checked and
set. It also makes the code cleaner & easier to grep for env knobs.
Change-Id: Id8a123ab7539f1fadbd27e0cbeac79c2e4f09751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It was accidentally deleted in the earlier 0022c3d2e (#2143) refactor.
Lock it in with a test.
Fixestailscale/corp#2503
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
To be scraped in the Go expvar JSON format, as a string is involved.
For a future tool to record when processes restarted exactly, and at
what version.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We want to use tsweb to format Prometheus-style metrics from
our temporary golang.org/x/net/http2 fork, but we don't want http2
to depend on the tailscale.com module to use the concrete type
tailscale.com/metrics.LabelMap. Instead, let a expvar.Map be used
instead of it's annotated sufficiently in its name.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
A previously added metric which was float64 was being ignored in tsweb, because it previously
only accepted int64 and ints. It can be handled in the same way as ints.
Signed-off-by: julianknodt <julianknodt@gmail.com>
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>
