pkg/srv, embed, etcdmain: Support multiple clusters in the same DNS discovery region.

release-3.4
Tavish Armstrong 2017-06-14 16:48:23 +00:00
parent 80250827ab
commit b664b9176c
4 changed files with 52 additions and 44 deletions

View File

@ -129,15 +129,16 @@ type Config struct {
// clustering
APUrls, ACUrls []url.URL
ClusterState string `json:"initial-cluster-state"`
DNSCluster string `json:"discovery-srv"`
Dproxy string `json:"discovery-proxy"`
Durl string `json:"discovery"`
InitialCluster string `json:"initial-cluster"`
InitialClusterToken string `json:"initial-cluster-token"`
StrictReconfigCheck bool `json:"strict-reconfig-check"`
EnableV2 bool `json:"enable-v2"`
APUrls, ACUrls []url.URL
ClusterState string `json:"initial-cluster-state"`
DNSCluster string `json:"discovery-srv"`
DNSClusterServiceName string `json:"discovery-srv-name"`
Dproxy string `json:"discovery-proxy"`
Durl string `json:"discovery"`
InitialCluster string `json:"initial-cluster"`
InitialClusterToken string `json:"initial-cluster-token"`
StrictReconfigCheck bool `json:"strict-reconfig-check"`
EnableV2 bool `json:"enable-v2"`
// security
@ -463,7 +464,8 @@ func (cfg *Config) PeerURLsMapAndToken(which string) (urlsmap types.URLsMap, tok
urlsmap[cfg.Name] = cfg.APUrls
token = cfg.Durl
case cfg.DNSCluster != "":
clusterStrs, cerr := srv.GetCluster("etcd-server", cfg.Name, cfg.DNSCluster, cfg.APUrls)
clusterStrs, cerr := cfg.GetDNSClusterNames()
if cerr != nil {
plog.Errorf("couldn't resolve during SRV discovery (%v)", cerr)
return nil, "", cerr
@ -490,6 +492,28 @@ func (cfg *Config) PeerURLsMapAndToken(which string) (urlsmap types.URLsMap, tok
return urlsmap, token, err
}
// GetDNSClusterNames uses DNS SRV records to get a list of initial nodes for cluster bootstrapping.
func (cfg *Config) GetDNSClusterNames() ([]string, error) {
var (
clusterStrs []string
cerr error
serviceNameSuffix string
)
if cfg.DNSClusterServiceName != "" {
serviceNameSuffix = "-" + cfg.DNSClusterServiceName
}
// Use both etcd-server-ssl and etcd-server for discovery. Combine the results if both are available.
clusterStrs, cerr = srv.GetCluster("https", "etcd-server-ssl"+serviceNameSuffix, cfg.Name, cfg.DNSCluster, cfg.APUrls)
defaultHTTPClusterStrs, httpCerr := srv.GetCluster("http", "etcd-server"+serviceNameSuffix, cfg.Name, cfg.DNSCluster, cfg.APUrls)
if cerr != nil {
clusterStrs = make([]string, 0)
}
if httpCerr != nil {
clusterStrs = append(clusterStrs, defaultHTTPClusterStrs...)
}
return clusterStrs, cerr
}
func (cfg Config) InitialClusterFromName(name string) (ret string) {
if len(cfg.APUrls) == 0 {
return ""

View File

@ -155,6 +155,7 @@ func newConfig() *config {
fs.StringVar(&cfg.ec.Dproxy, "discovery-proxy", cfg.ec.Dproxy, "HTTP proxy to use for traffic to discovery service.")
fs.StringVar(&cfg.ec.DNSCluster, "discovery-srv", cfg.ec.DNSCluster, "DNS domain used to bootstrap initial cluster.")
fs.StringVar(&cfg.ec.DNSClusterServiceName, "discovery-srv-name", cfg.ec.DNSClusterServiceName, "Service name to query when using DNS discovery.")
fs.StringVar(&cfg.ec.InitialCluster, "initial-cluster", cfg.ec.InitialCluster, "Initial cluster configuration for bootstrapping.")
fs.StringVar(&cfg.ec.InitialClusterToken, "initial-cluster-token", cfg.ec.InitialClusterToken, "Initial cluster token for the etcd cluster during bootstrap.")
fs.Var(cfg.cf.clusterState, "initial-cluster-state", "Initial cluster state ('new' or 'existing').")
@ -285,7 +286,7 @@ func (cfg *config) configFromCmdLine() error {
}
// disable default initial-cluster if discovery is set
if (cfg.ec.Durl != "" || cfg.ec.DNSCluster != "") && !flags.IsSet(cfg.cf.flagSet, "initial-cluster") {
if (cfg.ec.Durl != "" || cfg.ec.DNSCluster != "" || cfg.ec.DNSClusterServiceName != "") && !flags.IsSet(cfg.cf.flagSet, "initial-cluster") {
cfg.ec.InitialCluster = ""
}

View File

@ -32,7 +32,7 @@ var (
// GetCluster gets the cluster information via DNS discovery.
// Also sees each entry as a separate instance.
func GetCluster(service, name, dns string, apurls types.URLs) ([]string, error) {
func GetCluster(serviceScheme, service, name, dns string, apurls types.URLs) ([]string, error) {
tempName := int(0)
tcp2ap := make(map[string]url.URL)
@ -83,20 +83,9 @@ func GetCluster(service, name, dns string, apurls types.URLs) ([]string, error)
return nil
}
failCount := 0
err := updateNodeMap(service+"-ssl", "https")
srvErr := make([]string, 2)
err := updateNodeMap(service, serviceScheme)
if err != nil {
srvErr[0] = fmt.Sprintf("error querying DNS SRV records for _%s-ssl %s", service, err)
failCount++
}
err = updateNodeMap(service, "http")
if err != nil {
srvErr[1] = fmt.Sprintf("error querying DNS SRV records for _%s %s", service, err)
failCount++
}
if failCount == 2 {
return nil, fmt.Errorf("srv: too many errors querying DNS SRV records (%q, %q)", srvErr[0], srvErr[1])
return nil, fmt.Errorf("error querying DNS SRV records for _%s %s", service, err)
}
return stringParts, nil
}

View File

@ -44,51 +44,51 @@ func TestSRVGetCluster(t *testing.T) {
}
tests := []struct {
withSSL []*net.SRV
withoutSSL []*net.SRV
urls []string
scheme string
records []*net.SRV
urls []string
expected string
}{
{
[]*net.SRV{},
"https",
[]*net.SRV{},
nil,
"",
},
{
"https",
srvAll,
[]*net.SRV{},
nil,
"0=https://1.example.com:2480,1=https://2.example.com:2480,2=https://3.example.com:2480",
},
{
"http",
srvAll,
[]*net.SRV{{Target: "4.example.com.", Port: 2380}},
nil,
"0=https://1.example.com:2480,1=https://2.example.com:2480,2=https://3.example.com:2480,3=http://4.example.com:2380",
"0=http://1.example.com:2480,1=http://2.example.com:2480,2=http://3.example.com:2480",
},
{
"https",
srvAll,
[]*net.SRV{{Target: "4.example.com.", Port: 2380}},
[]string{"https://10.0.0.1:2480"},
"dnsClusterTest=https://1.example.com:2480,0=https://2.example.com:2480,1=https://3.example.com:2480,2=http://4.example.com:2380",
"dnsClusterTest=https://1.example.com:2480,0=https://2.example.com:2480,1=https://3.example.com:2480",
},
// matching local member with resolved addr and return unresolved hostnames
{
"https",
srvAll,
nil,
[]string{"https://10.0.0.1:2480"},
"dnsClusterTest=https://1.example.com:2480,0=https://2.example.com:2480,1=https://3.example.com:2480",
},
// reject if apurls are TLS but SRV is only http
{
nil,
"http",
srvAll,
[]string{"https://10.0.0.1:2480"},
@ -109,16 +109,10 @@ func TestSRVGetCluster(t *testing.T) {
for i, tt := range tests {
lookupSRV = func(service string, proto string, domain string) (string, []*net.SRV, error) {
if service == "etcd-server-ssl" {
return "", tt.withSSL, nil
}
if service == "etcd-server" {
return "", tt.withoutSSL, nil
}
return "", nil, errors.New("Unknown service in mock")
return "", tt.records, nil
}
urls := testutil.MustNewURLs(t, tt.urls)
str, err := GetCluster("etcd-server", name, "example.com", urls)
str, err := GetCluster(tt.scheme, "etcd-server", name, "example.com", urls)
if err != nil {
t.Fatalf("%d: err: %#v", i, err)
}