d1f17fa7e0
Move all (almost all) Go files in middleware into their own packages. This makes for better naming and discoverability. Lot of changes elsewhere to make this change. The middleware.State was renamed to request.Request which is better, but still does not cover all use-cases. It was also moved out middleware because it is used by `dnsserver` as well. A pkg/dnsutil packages was added for shared, handy, dns util functions. All normalize functions are now put in normalize.go
74 lines
1.9 KiB
Go
74 lines
1.9 KiB
Go
package cache
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import (
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"github.com/miekg/coredns/middleware"
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"github.com/miekg/coredns/request"
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"github.com/miekg/dns"
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"github.com/prometheus/client_golang/prometheus"
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"golang.org/x/net/context"
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)
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// ServeDNS implements the middleware.Handler interface.
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func (c Cache) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
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state := request.Request{W: w, Req: r}
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qname := state.Name()
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qtype := state.QType()
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zone := middleware.Zones(c.Zones).Matches(qname)
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if zone == "" {
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return c.Next.ServeDNS(ctx, w, r)
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}
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do := state.Do() // might need more from OPT record?
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if i, ok := c.get(qname, qtype, do); ok {
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resp := i.toMsg(r)
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state.SizeAndDo(resp)
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w.WriteMsg(resp)
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cacheHitCount.WithLabelValues(zone).Inc()
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return dns.RcodeSuccess, nil
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}
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cacheMissCount.WithLabelValues(zone).Inc()
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crr := NewCachingResponseWriter(w, c.cache, c.cap)
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return c.Next.ServeDNS(ctx, crr, r)
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}
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func (c Cache) get(qname string, qtype uint16, do bool) (*item, bool) {
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nxdomain := nameErrorKey(qname, do)
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if i, ok := c.cache.Get(nxdomain); ok {
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return i.(*item), true
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}
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// TODO(miek): delegation was added double check
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successOrNoData := successKey(qname, qtype, do)
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if i, ok := c.cache.Get(successOrNoData); ok {
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return i.(*item), true
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}
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return nil, false
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}
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var (
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cacheHitCount = prometheus.NewCounterVec(prometheus.CounterOpts{
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Namespace: middleware.Namespace,
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Subsystem: subsystem,
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Name: "hit_count_total",
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Help: "Counter of DNS requests that were found in the cache.",
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}, []string{"zone"})
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cacheMissCount = prometheus.NewCounterVec(prometheus.CounterOpts{
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Namespace: middleware.Namespace,
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Subsystem: subsystem,
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Name: "miss_count_total",
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Help: "Counter of DNS requests that were not found in the cache.",
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}, []string{"zone"})
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)
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const subsystem = "cache"
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func init() {
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prometheus.MustRegister(cacheHitCount)
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prometheus.MustRegister(cacheMissCount)
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}
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