219bfd0493
* middleware/metrics: add more metrics middleware/cache: Add metrics for number of elements in the cache. Also export the total size. Update README to detail the new metrics. middleware/metrics Move metrics into subpackage called "vars". This breaks the import cycle and is cleaner. This allows vars.Report to be used in the the dnsserver to log refused queries. middleware/metrics: tests Add tests to the metrics framework. The metrics/test subpackage allows scraping of the local server. Do a few test scrape of the metrics that are defined in the metrics middleware. This also allows metrics integration tests to check if the caching and dnssec middleware export their metrics correctly. * update README * typos * fix tests
99 lines
2 KiB
Go
99 lines
2 KiB
Go
// Package metrics implement a handler and middleware that provides Prometheus metrics.
|
|
package metrics
|
|
|
|
import (
|
|
"log"
|
|
"net"
|
|
"net/http"
|
|
"sync"
|
|
|
|
"github.com/miekg/coredns/middleware"
|
|
"github.com/miekg/coredns/middleware/metrics/vars"
|
|
|
|
"github.com/prometheus/client_golang/prometheus"
|
|
)
|
|
|
|
// Metrics holds the prometheus configuration. The metrics' path is fixed to be /metrics
|
|
type Metrics struct {
|
|
Next middleware.Handler
|
|
Addr string
|
|
ln net.Listener
|
|
mux *http.ServeMux
|
|
Once sync.Once
|
|
|
|
zoneNames []string
|
|
zoneMap map[string]bool
|
|
zoneMu sync.RWMutex
|
|
}
|
|
|
|
// AddZone adds zone z to m.
|
|
func (m *Metrics) AddZone(z string) {
|
|
m.zoneMu.Lock()
|
|
m.zoneMap[z] = true
|
|
m.zoneNames = keys(m.zoneMap)
|
|
m.zoneMu.Unlock()
|
|
}
|
|
|
|
// RemoveZone remove zone z from m.
|
|
func (m *Metrics) RemoveZone(z string) {
|
|
m.zoneMu.Lock()
|
|
delete(m.zoneMap, z)
|
|
m.zoneNames = keys(m.zoneMap)
|
|
m.zoneMu.Unlock()
|
|
}
|
|
|
|
// ZoneNames returns the zones of m.
|
|
func (m *Metrics) ZoneNames() []string {
|
|
m.zoneMu.RLock()
|
|
s := m.zoneNames
|
|
m.zoneMu.RUnlock()
|
|
return s
|
|
}
|
|
|
|
// OnStartup sets up the metrics on startup.
|
|
func (m *Metrics) OnStartup() error {
|
|
m.Once.Do(func() {
|
|
|
|
ln, err := net.Listen("tcp", m.Addr)
|
|
if err != nil {
|
|
log.Printf("[ERROR] Failed to start metrics handler: %s", err)
|
|
return
|
|
}
|
|
|
|
m.ln = ln
|
|
|
|
m.mux = http.NewServeMux()
|
|
|
|
prometheus.MustRegister(vars.RequestCount)
|
|
prometheus.MustRegister(vars.RequestDuration)
|
|
prometheus.MustRegister(vars.RequestSize)
|
|
prometheus.MustRegister(vars.RequestDo)
|
|
prometheus.MustRegister(vars.RequestType)
|
|
|
|
prometheus.MustRegister(vars.ResponseSize)
|
|
prometheus.MustRegister(vars.ResponseRcode)
|
|
|
|
m.mux.Handle("/metrics", prometheus.Handler())
|
|
|
|
go func() {
|
|
http.Serve(m.ln, m.mux)
|
|
}()
|
|
})
|
|
return nil
|
|
}
|
|
|
|
// OnShutdown tears down the metrics on shutdown.
|
|
func (m *Metrics) OnShutdown() error {
|
|
if m.ln != nil {
|
|
return m.ln.Close()
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func keys(m map[string]bool) []string {
|
|
sx := []string{}
|
|
for k := range m {
|
|
sx = append(sx, k)
|
|
}
|
|
return sx
|
|
}
|