Revert "Merge pull request #317 from prometheus/fix/miekg-dns-for-srv"

This reverts commit e3bc6fc9dc, reversing
changes made to 1cf9e5840a.

Conflicts:
	retrieval/target_provider.go

Change-Id: Icb6e98fb30419e9e2fe9b686c243702ced372014
This commit is contained in:
Johannes 'fish' Ziemke 2013-08-30 16:16:49 +02:00
parent 7910f6e863
commit 88099328d1
2 changed files with 5 additions and 75 deletions

View File

@ -45,7 +45,7 @@ cc-implementation-Linux-stamp:
[ -x "$$(which cc)" ] || $(APT_GET_INSTALL) build-essential
touch $@
dependencies-stamp: cache-stamp cc-stamp leveldb-stamp snappy-stamp godns-stamp
dependencies-stamp: cache-stamp cc-stamp leveldb-stamp snappy-stamp
touch $@
goprotobuf-protoc-gen-go-stamp: protoc-stamp goprotobuf-stamp
@ -56,10 +56,6 @@ goprotobuf-stamp: protoc-stamp
$(GO_GET) code.google.com/p/goprotobuf/proto $(THIRD_PARTY_BUILD_OUTPUT)
touch $@
godns-stamp:
$(GO_GET) github.com/miekg/dns $(THIRD_PARTY_BUILD_OUTPUT)
touch $@
leveldb-stamp: cache-stamp cache/leveldb-$(LEVELDB_VERSION).tar.gz cc-stamp rsync-stamp snappy-stamp
tar xzvf cache/leveldb-$(LEVELDB_VERSION).tar.gz -C dirty $(THIRD_PARTY_BUILD_OUTPUT)
cd dirty/leveldb-$(LEVELDB_VERSION) && CFLAGS="$(CFLAGS) -lsnappy" CXXFLAGS="$(CXXFLAGS) -lsnappy $(LDFLAGS)" LDFLAGS="-lsnappy $(LDFLAGS)" bash -x ./build_detect_platform build_config.mk ./

View File

@ -15,20 +15,16 @@ package retrieval
import (
"fmt"
"net"
"net/url"
"time"
"github.com/golang/glog"
"github.com/miekg/dns"
clientmodel "github.com/prometheus/client_golang/model"
"github.com/prometheus/prometheus/config"
"github.com/prometheus/prometheus/utility"
)
const resolvConf = "/etc/resolv.conf"
// TargetProvider encapsulates retrieving all targets for a job.
type TargetProvider interface {
// Retrieves the current list of targets for this provider.
@ -61,7 +57,7 @@ func (p *sdTargetProvider) Targets() ([]Target, error) {
return p.targets, nil
}
response, err := lookupSRV(p.job.GetSdName())
_, addrs, err := net.LookupSRV("", "", p.job.GetSdName())
if err != nil {
return nil, err
}
@ -70,17 +66,12 @@ func (p *sdTargetProvider) Targets() ([]Target, error) {
clientmodel.JobLabel: clientmodel.LabelValue(p.job.GetName()),
}
targets := make([]Target, 0, len(response.Answer))
targets := make([]Target, 0, len(addrs))
endpoint := &url.URL{
Scheme: "http",
Path: p.job.GetMetricsPath(),
}
for _, record := range response.Answer {
addr, ok := record.(*dns.SRV)
if !ok {
glog.Warningf("%s is not a valid SRV record", addr)
continue
}
for _, addr := range addrs {
// Remove the final dot from rooted DNS names to make them look more usual.
if addr.Target[len(addr.Target)-1] == '.' {
addr.Target = addr.Target[:len(addr.Target)-1]
@ -93,60 +84,3 @@ func (p *sdTargetProvider) Targets() ([]Target, error) {
p.targets = targets
return targets, nil
}
func lookupSRV(name string) (*dns.Msg, error) {
name = dns.Fqdn(name)
conf, err := dns.ClientConfigFromFile(resolvConf)
if err != nil {
return nil, fmt.Errorf("Couldn't load resolv.conf: %s", err)
}
client := &dns.Client{}
msg := &dns.Msg{}
msg.SetQuestion(name, dns.TypeSRV)
response := &dns.Msg{}
for _, server := range conf.Servers {
server := fmt.Sprintf("%s:%s", server, conf.Port)
response, err = lookup(msg, client, server, false)
if err == nil {
return response, nil
}
}
return response, fmt.Errorf("Couldn't resolve %s: No server responded", name)
}
func lookup(msg *dns.Msg, client *dns.Client, server string, edns bool) (*dns.Msg, error) {
if edns {
opt := &dns.OPT{
Hdr: dns.RR_Header{
Name: ".",
Rrtype: dns.TypeOPT,
},
}
opt.SetUDPSize(dns.DefaultMsgSize)
msg.Extra = append(msg.Extra, opt)
}
response, _, err := client.Exchange(msg, server)
if err != nil {
return nil, err
}
if msg.Id != response.Id {
return nil, fmt.Errorf("DNS ID mismatch, request: %d, response: %d", msg.Id, response.Id)
}
if response.MsgHdr.Truncated {
if client.Net == "tcp" {
return nil, fmt.Errorf("Got truncated message on tcp")
}
if edns { // Truncated even though EDNS is used
client.Net = "tcp"
}
return lookup(msg, client, server, !edns)
}
return response, nil
}