9ac3cab1b7
* Make CoreDNS a server type plugin for Caddy Remove code we don't need and port all middleware over. Fix all tests and rework the documentation. Also make `go generate` build a caddy binary which we then copy into our directory. This means `go build`-builds remain working as-is. And new etc instances in each etcd test for better isolation. Fix more tests and rework test.Server with the newer support Caddy offers. Fix Makefile to support new mode of operation.
118 lines
2.9 KiB
Go
118 lines
2.9 KiB
Go
package kubernetes
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import (
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"fmt"
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"strings"
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"github.com/miekg/coredns/middleware"
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"github.com/miekg/dns"
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"golang.org/x/net/context"
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)
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func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
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state := middleware.State{W: w, Req: r}
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if state.QClass() != dns.ClassINET {
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return dns.RcodeServerFailure, fmt.Errorf("can only deal with ClassINET")
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}
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m := new(dns.Msg)
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m.SetReply(r)
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m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
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// TODO: find an alternative to this block
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if strings.HasSuffix(state.Name(), arpaSuffix) {
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ip, _ := extractIP(state.Name())
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records := k.getServiceRecordForIP(ip, state.Name())
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if len(records) > 0 {
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srvPTR := &records[0]
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m.Answer = append(m.Answer, srvPTR.NewPTR(state.QName(), ip))
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m = dedup(m)
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state.SizeAndDo(m)
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m, _ = state.Scrub(m)
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w.WriteMsg(m)
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return dns.RcodeSuccess, nil
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}
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}
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// Check that query matches one of the zones served by this middleware,
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// otherwise delegate to the next in the pipeline.
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zone := middleware.Zones(k.Zones).Matches(state.Name())
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if zone == "" {
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if k.Next == nil {
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return dns.RcodeServerFailure, nil
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}
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return k.Next.ServeDNS(ctx, w, r)
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}
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var (
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records, extra []dns.RR
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err error
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)
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switch state.Type() {
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case "A":
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records, err = k.A(zone, state, nil)
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case "AAAA":
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records, err = k.AAAA(zone, state, nil)
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case "TXT":
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records, err = k.TXT(zone, state)
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// TODO: change lookup to return appropriate error. Then add code below
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// this switch to check for the error and return not implemented.
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//return dns.RcodeNotImplemented, nil
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case "CNAME":
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records, err = k.CNAME(zone, state)
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case "MX":
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records, extra, err = k.MX(zone, state)
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case "SRV":
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records, extra, err = k.SRV(zone, state)
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case "SOA":
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records = []dns.RR{k.SOA(zone, state)}
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case "NS":
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if state.Name() == zone {
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records, extra, err = k.NS(zone, state)
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break
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}
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fallthrough
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default:
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// Do a fake A lookup, so we can distinguish betwen NODATA and NXDOMAIN
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_, err = k.A(zone, state, nil)
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}
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if isKubernetesNameError(err) {
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return k.Err(zone, dns.RcodeNameError, state)
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}
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if err != nil {
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return dns.RcodeServerFailure, err
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}
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if len(records) == 0 {
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return k.Err(zone, dns.RcodeSuccess, state)
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}
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m.Answer = append(m.Answer, records...)
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m.Extra = append(m.Extra, extra...)
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m = dedup(m)
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state.SizeAndDo(m)
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m, _ = state.Scrub(m)
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w.WriteMsg(m)
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return dns.RcodeSuccess, nil
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}
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// NoData write a nodata response to the client.
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func (k Kubernetes) Err(zone string, rcode int, state middleware.State) (int, error) {
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m := new(dns.Msg)
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m.SetRcode(state.Req, rcode)
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m.Ns = []dns.RR{k.SOA(zone, state)}
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state.SizeAndDo(m)
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state.W.WriteMsg(m)
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return rcode, nil
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}
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func dedup(m *dns.Msg) *dns.Msg {
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// TODO(miek): expensive!
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m.Answer = dns.Dedup(m.Answer, nil)
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m.Ns = dns.Dedup(m.Ns, nil)
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m.Extra = dns.Dedup(m.Extra, nil)
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return m
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}
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