4df416ca1d
* 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)
24 lines
677 B
Go
24 lines
677 B
Go
package metrics
|
|
|
|
import (
|
|
"github.com/coredns/coredns/plugin"
|
|
|
|
"golang.org/x/net/context"
|
|
)
|
|
|
|
// WithServer returns the current server handling the request. It returns the
|
|
// server listening address: <scheme>://[<bind>]:<port> Normally this is
|
|
// something like "dns://:53", but if the bind plugin is used, i.e. "bind
|
|
// 127.0.0.53", it will be "dns://127.0.0.53:53", etc. If not address is found
|
|
// the empty string is returned.
|
|
//
|
|
// Basic usage with a metric:
|
|
//
|
|
// <metric>.WithLabelValues(metrics.WithServer(ctx), labels..).Add(1)
|
|
func WithServer(ctx context.Context) string {
|
|
srv := ctx.Value(plugin.ServerCtx{})
|
|
if srv == nil {
|
|
return ""
|
|
}
|
|
return srv.(string)
|
|
}
|