Merge pull request #62 from josselin-c/master

Add support for multiple etcd endpoints

main.go

@@ -24,19 +24,19 @@ import (
 )
 
 type CmdLineOpts struct {
-	etcdEndpoint string
-	etcdPrefix   string
-	help         bool
-	version      bool
-	ipMasq       bool
-	subnetFile   string
-	iface        string
+	etcdEndpoints string
+	etcdPrefix    string
+	help          bool
+	version       bool
+	ipMasq        bool
+	subnetFile    string
+	iface         string
 }
 
 var opts CmdLineOpts
 
 func init() {
-	flag.StringVar(&opts.etcdEndpoint, "etcd-endpoint", "http://127.0.0.1:4001", "etcd endpoint")
+	flag.StringVar(&opts.etcdEndpoints, "etcd-endpoints", "http://127.0.0.1:4001", "a comma-delimited list of etcd endpoints")
 	flag.StringVar(&opts.etcdPrefix, "etcd-prefix", "/coreos.com/network", "etcd prefix")
 	flag.StringVar(&opts.subnetFile, "subnet-file", "/run/flannel/subnet.env", "filename where env variables (subnet and MTU values) will be written to")
 	flag.StringVar(&opts.iface, "iface", "", "interface to use (IP or name) for inter-host communication")
@@ -125,8 +125,10 @@ func lookupIface() (*net.Interface, net.IP, error) {
 }
 
 func makeSubnetManager() *subnet.SubnetManager {
+	peers := strings.Split(opts.etcdEndpoints, ",")
+
 	for {
-		sm, err := subnet.NewSubnetManager(opts.etcdEndpoint, opts.etcdPrefix)
+		sm, err := subnet.NewSubnetManager(peers, opts.etcdPrefix)
 		if err == nil {
 			return sm
 		}

subnet/registry.go

@@ -20,13 +20,13 @@ type subnetRegistry interface {
 type etcdSubnetRegistry struct {
 	mux      sync.Mutex
 	cli      *etcd.Client
-	endpoint string
+	endpoint []string
 	prefix   string
 }
 
-func newEtcdSubnetRegistry(endpoint, prefix string) subnetRegistry {
+func newEtcdSubnetRegistry(endpoint []string, prefix string) subnetRegistry {
 	return &etcdSubnetRegistry{
-		cli:      etcd.NewClient([]string{endpoint}),
+		cli:      etcd.NewClient(endpoint),
 		endpoint: endpoint,
 		prefix:   prefix,
 	}
@@ -101,7 +101,7 @@ func (esr *etcdSubnetRegistry) client() *etcd.Client {
 func (esr *etcdSubnetRegistry) resetClient() {
 	esr.mux.Lock()
 	defer esr.mux.Unlock()
-	esr.cli = etcd.NewClient([]string{esr.endpoint})
+	esr.cli = etcd.NewClient(esr.endpoint)
 }
 
 func ensureExpiration(resp *etcd.Response, ttl uint64) {

subnet/subnet.go

@@ -61,7 +61,7 @@ type Event struct {
 
 type EventBatch []Event
 
-func NewSubnetManager(etcdEndpoint, prefix string) (*SubnetManager, error) {
+func NewSubnetManager(etcdEndpoint []string, prefix string) (*SubnetManager, error) {
 	esr := newEtcdSubnetRegistry(etcdEndpoint, prefix)
 	return newSubnetManager(esr)
 }