* plugin/metrics: set server address in context
Allow cross server block metrics to co-exist; for this we should label
each metric with the server label. Put this information in the context
and provide a helper function to get it out.
Abstracting with entirely away with difficult as the release client_go
(0.8.0) doesn't have the CurryWith functions yet. So current use is like
so:
define metric, with server label:
RcodeCount = prometheus.NewCounterVec(prometheus.CounterOpts{
Namespace: plugin.Namespace,
Subsystem: "forward",
Name: "response_rcode_count_total",
Help: "Counter of requests made per upstream.",
}, []string{"server", "rcode", "to"})
And report ith with the helper function metrics.WithServer:
RcodeCount.WithLabelValues(metrics.WithServer(ctx), rc, p.addr).Add(1)
This should have everyone, but the process was quite manual. The rename
from middleware -> plugin also meant I had to do some extra digging on
who actually submitted the PR. I also double checked the current list of
people with commit access.
Every plugin now has an OWNERS, except *reverse*. I'll file a bug for
that.
* Add manual pages
Generate manual pages from the README and extend README with Name and
Description sections.
The generation requires 'ronn' which may not be available. Just check in
all generated manual pages.
This leave most of the code intact, but we need to stop vendoring
prometheus, because, again, plugins what want to use it. Not vendoring
prometheus makes my forward metrics show up again. Code looks bit
convoluted, but works:
~~~
c.OnStartup(func() error {
once.Do(func() {
m := dnsserver.GetConfig(c).Handler("prometheus")
if m == nil {
return
}
if x, ok := m.(*metrics.Metrics); ok {
x.MustRegister(RequestCount)
x.MustRegister(RcodeCount)
x.MustRegister(RequestDuration)
x.MustRegister(HealthcheckFailureCount)
x.MustRegister(SocketGauge)
}
})
})
~~~
prometheus.Handler is deprecated according to the godoc for the package so
instead we're using promhttp.
Additionally, we are exposing the Registry that metrics is using so other
plugins that are not inside of coredns can read the registry. Otherwise, if
we kept using the Default one, there's no way to access that from outside
of the coredns repo since it is vendored.
If external plugins wanted to extend metrics there was no way since
zoneNames couldn't be initialized. Now plugins can call New to get an
instance of Metrics that they can extend.
We support ENV variables in config files, add an example in the one for
metric, note that `localhost:` is a valid host (in Go), so the
TestReadme will parse this correctly.
Fixes#1150
* doc update
Go through all README and fix mistakes, extend example and let more
corefile snippets be test for validity.
* Cant use spefic addr in test
Add a full test server impl in this new package + tests. Move
dnsrecorder into this package as well and finish up the commented out
tests that were left in the old dnsrecorder package.
Update all callers and tests.
* Rename middleware to plugin
first pass; mostly used 'sed', few spots where I manually changed
text.
This still builds a coredns binary.
* fmt error
* Rename AddMiddleware to AddPlugin
* Readd AddMiddleware to remain backwards compat
