TrueCloudLab/coredns
16
0
Fork 2
Code Issues Pull requests 1 Projects Releases Packages Wiki Activity Actions

Metrics (#1579)

Browse source 
* 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 commit is contained in:
Miek Gieben 2018-04-01 13:57:03 +01:00 • committed by GitHub
parent 5c5a98ee29
commit 4df416ca1d
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 43 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

19
core/dnsserver/server.go
View file

@ -245,6 +245,11 @@ func (s *Server) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
}
if h, ok := s.zones[string(b[:l])]; ok {
// Set server's address in the context so plugins can reference back to this,
// This will makes those metrics unique.
ctx = context.WithValue(ctx, plugin.ServerCtx{}, s.Addr)
if r.Question[0].Qtype != dns.TypeDS {
if h.FilterFunc == nil {
rcode, _ := h.pluginChain.ServeDNS(ctx, w, r)
@ -287,6 +292,10 @@ func (s *Server) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
// Wildcard match, if we have found nothing try the root zone as a last resort.
if h, ok := s.zones["."]; ok && h.pluginChain != nil {
// See comment above.
ctx = context.WithValue(ctx, plugin.ServerCtx{}, s.Addr)
rcode, _ := h.pluginChain.ServeDNS(ctx, w, r)
if !plugin.ClientWrite(rcode) {
DefaultErrorFunc(w, r, rcode)
@ -359,11 +368,11 @@ const (
maxreentries = 10
)
// Key is the context key for the current server
type Key struct{}
// loopKey is the context key for counting self loops
type loopKey struct{}
type (
// Key is the context key for the current server
Key struct{}
loopKey struct{} // loopKey is the context key for counting self loops
)
// enableChaos is a map with plugin names for which we should open CH class queries as
// we block these by default.