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				https://github.com/coredns/coredns.git
				synced 2025-10-31 10:13:14 -04:00 
			
		
		
		
	
		
			
				
	
	
		
			84 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			84 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| package metrics
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| 
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| import (
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| 	"log"
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| 	"net/http"
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| 	"sync"
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| 
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| 	"github.com/miekg/coredns/middleware"
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| 	"github.com/prometheus/client_golang/prometheus"
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| )
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| 
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| const namespace = "coredns"
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| 
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| var (
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| 	requestCount    *prometheus.CounterVec
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| 	requestDuration *prometheus.HistogramVec
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| 	responseSize    *prometheus.HistogramVec
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| 	responseRcode   *prometheus.CounterVec
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| )
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| 
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| const path = "/metrics"
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| 
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| // Metrics holds the prometheus configuration. The metrics' path is fixed to be /metrics
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| type Metrics struct {
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| 	Next      middleware.Handler
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| 	Addr      string // where to we listen
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| 	Once      sync.Once
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| 	ZoneNames []string
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| }
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| 
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| func (m *Metrics) Start() error {
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| 	m.Once.Do(func() {
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| 		define("")
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| 
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| 		prometheus.MustRegister(requestCount)
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| 		prometheus.MustRegister(requestDuration)
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| 		prometheus.MustRegister(responseSize)
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| 		prometheus.MustRegister(responseRcode)
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| 
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| 		http.Handle(path, prometheus.Handler())
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| 		go func() {
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| 			if err := http.ListenAndServe(m.Addr, nil); err != nil {
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| 				log.Printf("[ERROR] Failed to start prometheus handler: %s", err)
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| 			}
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| 		}()
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| 	})
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| 	return nil
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| }
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| 
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| func define(subsystem string) {
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| 	if subsystem == "" {
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| 		subsystem = "dns"
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| 	}
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| 	requestCount = prometheus.NewCounterVec(prometheus.CounterOpts{
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| 		Namespace: namespace,
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| 		Subsystem: subsystem,
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| 		Name:      "request_count_total",
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| 		Help:      "Counter of DNS requests made per zone and type and opcode.",
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| 	}, []string{"zone", "qtype"})
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| 
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| 	requestDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
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| 		Namespace: namespace,
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| 		Subsystem: subsystem,
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| 		Name:      "request_duration_seconds",
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| 		Buckets:   append([]float64{.0001, .0005, .001, .0025}, prometheus.DefBuckets...),
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| 		Help:      "Histogram of the time (in seconds) each request took.",
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| 	}, []string{"zone", "qtype"})
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| 
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| 	responseSize = prometheus.NewHistogramVec(prometheus.HistogramOpts{
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| 		Namespace: namespace,
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| 		Subsystem: subsystem,
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| 		Name:      "response_size_bytes",
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| 		Help:      "Size of the returns response in bytes.",
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| 		Buckets:   []float64{0, 100, 200, 300, 400, 511, 1023, 2047, 4095, 8291, 16e3, 32e3, 48e3, 64e3},
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| 	}, []string{"zone", "qtype"})
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| 
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| 	responseRcode = prometheus.NewCounterVec(prometheus.CounterOpts{
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| 		Namespace: namespace,
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| 		Subsystem: subsystem,
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| 		Name:      "response_rcode_count_total",
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| 		Help:      "Counter of response status codes.",
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| 	}, []string{"zone", "rcode", "qtype"})
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| }
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