From 705ec450830035a5d3cb4a5e9fd157ec098410a8 Mon Sep 17 00:00:00 2001 From: Kelsey Hightower Date: Wed, 24 Dec 2014 03:29:28 -0500 Subject: [PATCH] etcdmain: resolve DNS hostnames for client and peer URLs etcd resolves DNS hostnames to IP addresses for client and peer URLs before creating any listening sockets. The following messages are logged during startup: etcd: Resolving infra0.coreos.com:2380 to 10.0.1.10:2380 Fixes #1991 --- etcdmain/config.go | 10 +++ pkg/netutil/netutil.go | 57 +++++++++++++++ pkg/netutil/netutil_test.go | 140 ++++++++++++++++++++++++++++++++++++ test | 2 +- 4 files changed, 208 insertions(+), 1 deletion(-) create mode 100644 pkg/netutil/netutil.go create mode 100644 pkg/netutil/netutil_test.go diff --git a/etcdmain/config.go b/etcdmain/config.go index a138071a9..c9d65e0f6 100644 --- a/etcdmain/config.go +++ b/etcdmain/config.go @@ -17,6 +17,7 @@ package etcdmain import ( + "errors" "flag" "fmt" "log" @@ -27,6 +28,7 @@ import ( "github.com/coreos/etcd/etcdserver" "github.com/coreos/etcd/pkg/cors" "github.com/coreos/etcd/pkg/flags" + "github.com/coreos/etcd/pkg/netutil" "github.com/coreos/etcd/pkg/transport" "github.com/coreos/etcd/version" ) @@ -242,9 +244,17 @@ func (cfg *config) Parse(arguments []string) error { return err } + if err := cfg.resolveUrls(); err != nil { + return errors.New("cannot resolve DNS hostnames.") + } + return nil } +func (cfg *config) resolveUrls() error { + return netutil.ResolveTCPAddrs(cfg.lpurls, cfg.apurls, cfg.lcurls, cfg.acurls) +} + func (cfg config) isNewCluster() bool { return cfg.clusterState.String() == clusterStateFlagNew } func (cfg config) isProxy() bool { return cfg.proxy.String() != proxyFlagOff } func (cfg config) isReadonlyProxy() bool { return cfg.proxy.String() == proxyFlagReadonly } diff --git a/pkg/netutil/netutil.go b/pkg/netutil/netutil.go new file mode 100644 index 000000000..655bf1902 --- /dev/null +++ b/pkg/netutil/netutil.go @@ -0,0 +1,57 @@ +/* + Copyright 2014 CoreOS, Inc. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +package netutil + +import ( + "log" + "net" + "net/url" +) + +var ( + // indirection for testing + resolveTCPAddr = net.ResolveTCPAddr +) + +// ResolveTCPAddrs is a convenience wrapper for net.ResolveTCPAddr. +// ResolveTCPAddrs resolves all DNS hostnames in-place for the given set of +// url.URLs. +func ResolveTCPAddrs(urls ...[]url.URL) error { + for _, us := range urls { + for i, u := range us { + host, _, err := net.SplitHostPort(u.Host) + if err != nil { + log.Printf("netutil: Could not parse url %s during tcp resolving.", u.Host) + return err + } + if host == "localhost" { + continue + } + if net.ParseIP(host) != nil { + continue + } + tcpAddr, err := resolveTCPAddr("tcp", u.Host) + if err != nil { + log.Printf("netutil: Could not resolve host: %s", u.Host) + return err + } + log.Printf("netutil: Resolving %s to %s", u.Host, tcpAddr.String()) + us[i].Host = tcpAddr.String() + } + } + return nil +} diff --git a/pkg/netutil/netutil_test.go b/pkg/netutil/netutil_test.go new file mode 100644 index 000000000..e2a50d8cc --- /dev/null +++ b/pkg/netutil/netutil_test.go @@ -0,0 +1,140 @@ +/* + Copyright 2014 CoreOS, Inc. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +package netutil + +import ( + "errors" + "net" + "net/url" + "reflect" + "strconv" + "testing" +) + +func TestResolveTCPAddrs(t *testing.T) { + defer func() { resolveTCPAddr = net.ResolveTCPAddr }() + tests := []struct { + urls [][]url.URL + expected [][]url.URL + hostMap map[string]string + hasError bool + }{ + { + urls: [][]url.URL{ + []url.URL{ + url.URL{Scheme: "http", Host: "127.0.0.1:4001"}, + url.URL{Scheme: "http", Host: "127.0.0.1:2379"}, + }, + []url.URL{ + url.URL{Scheme: "http", Host: "127.0.0.1:7001"}, + url.URL{Scheme: "http", Host: "127.0.0.1:2380"}, + }, + }, + expected: [][]url.URL{ + []url.URL{ + url.URL{Scheme: "http", Host: "127.0.0.1:4001"}, + url.URL{Scheme: "http", Host: "127.0.0.1:2379"}, + }, + []url.URL{ + url.URL{Scheme: "http", Host: "127.0.0.1:7001"}, + url.URL{Scheme: "http", Host: "127.0.0.1:2380"}, + }, + }, + }, + { + urls: [][]url.URL{ + []url.URL{ + url.URL{Scheme: "http", Host: "infra0.example.com:4001"}, + url.URL{Scheme: "http", Host: "infra0.example.com:2379"}, + }, + []url.URL{ + url.URL{Scheme: "http", Host: "infra0.example.com:7001"}, + url.URL{Scheme: "http", Host: "infra0.example.com:2380"}, + }, + }, + expected: [][]url.URL{ + []url.URL{ + url.URL{Scheme: "http", Host: "10.0.1.10:4001"}, + url.URL{Scheme: "http", Host: "10.0.1.10:2379"}, + }, + []url.URL{ + url.URL{Scheme: "http", Host: "10.0.1.10:7001"}, + url.URL{Scheme: "http", Host: "10.0.1.10:2380"}, + }, + }, + hostMap: map[string]string{ + "infra0.example.com": "10.0.1.10", + }, + hasError: false, + }, + { + urls: [][]url.URL{ + []url.URL{ + url.URL{Scheme: "http", Host: "infra0.example.com:4001"}, + url.URL{Scheme: "http", Host: "infra0.example.com:2379"}, + }, + []url.URL{ + url.URL{Scheme: "http", Host: "infra0.example.com:7001"}, + url.URL{Scheme: "http", Host: "infra0.example.com:2380"}, + }, + }, + hostMap: map[string]string{ + "infra0.example.com": "", + }, + hasError: true, + }, + { + urls: [][]url.URL{ + []url.URL{ + url.URL{Scheme: "http", Host: "ssh://infra0.example.com:4001"}, + url.URL{Scheme: "http", Host: "ssh://infra0.example.com:2379"}, + }, + []url.URL{ + url.URL{Scheme: "http", Host: "ssh://infra0.example.com:7001"}, + url.URL{Scheme: "http", Host: "ssh://infra0.example.com:2380"}, + }, + }, + hasError: true, + }, + } + for _, tt := range tests { + resolveTCPAddr = func(network, addr string) (*net.TCPAddr, error) { + host, port, err := net.SplitHostPort(addr) + if err != nil { + return nil, err + } + if tt.hostMap[host] == "" { + return nil, errors.New("cannot resolve host.") + } + i, err := strconv.Atoi(port) + if err != nil { + return nil, err + } + return &net.TCPAddr{IP: net.ParseIP(tt.hostMap[host]), Port: i, Zone: ""}, nil + } + err := ResolveTCPAddrs(tt.urls...) + if tt.hasError { + if err == nil { + t.Errorf("expected error") + } + continue + } + if !reflect.DeepEqual(tt.urls, tt.expected) { + t.Errorf("expected: %v, got %v", tt.expected, tt.urls) + } + } +} diff --git a/test b/test index 1a87669e5..c2ad2c009 100755 --- a/test +++ b/test @@ -15,7 +15,7 @@ COVER=${COVER:-"-cover"} source ./build # Hack: gofmt ./ will recursively check the .git directory. So use *.go for gofmt. -TESTABLE_AND_FORMATTABLE="client discovery error etcdctl/command etcdmain etcdserver etcdserver/etcdhttp etcdserver/etcdhttp/httptypes etcdserver/etcdserverpb integration migrate pkg/fileutil pkg/flags pkg/ioutils pkg/types pkg/transport pkg/wait proxy raft rafthttp snap store wal" +TESTABLE_AND_FORMATTABLE="client discovery error etcdctl/command etcdmain etcdserver etcdserver/etcdhttp etcdserver/etcdhttp/httptypes etcdserver/etcdserverpb integration migrate pkg/fileutil pkg/flags pkg/ioutils pkg/netutil pkg/types pkg/transport pkg/wait proxy raft rafthttp snap store wal" FORMATTABLE="$TESTABLE_AND_FORMATTABLE *.go etcdctl/" # user has not provided PKG override