libnetwork: remove global store from overlay driver

The overlay driver was creating a global store whenever
netlabel.GlobalKVClient was specified in its config argument. This
specific label is not used anymore since 142b522 (moby/moby#44875).

golangci-lint now detects dead code. This will be fixed in subsequent
commits.

Signed-off-by: Albin Kerouanton <albinker@gmail.com>

libnetwork/drivers/overlay/ov_network.go

@@ -166,10 +166,6 @@ func (d *driver) CreateNetwork(id string, option map[string]interface{}, nInfo d
 		return fmt.Errorf("attempt to create overlay network %v that already exists", n.id)
 	}
 
-	if err := n.writeToStore(); err != nil {
-		return fmt.Errorf("failed to update data store for network %v: %v", n.id, err)
-	}
-
 	// Make sure no rule is on the way from any stale secure network
 	if !n.secure {
 		for _, vni := range vnis {
@@ -213,10 +209,7 @@ func (d *driver) DeleteNetwork(nid string) error {
 
 	// This is similar to d.network(), but we need to keep holding the lock
 	// until we are done removing this network.
-	n, ok := d.networks[nid]
-	if !ok {
-		n = d.restoreNetworkFromStore(nid)
-	}
+	n := d.networks[nid]
 	if n == nil {
 		return fmt.Errorf("could not find network with id %s", nid)
 	}
@@ -878,42 +871,14 @@ func (n *network) watchMiss(nlSock *nl.NetlinkSocket, nsPath string) {
 	}
 }
 
-// Restore a network from the store to the driver if it is present.
-// Must be called with the driver locked!
-func (d *driver) restoreNetworkFromStore(nid string) *network {
-	n := d.getNetworkFromStore(nid)
-	if n != nil {
-		n.driver = d
-		n.endpoints = endpointTable{}
-		d.networks[nid] = n
-	}
-	return n
-}
-
 func (d *driver) network(nid string) *network {
 	d.Lock()
-	n, ok := d.networks[nid]
-	if !ok {
-		n = d.restoreNetworkFromStore(nid)
-	}
+	n := d.networks[nid]
 	d.Unlock()
 
 	return n
 }
 
-func (d *driver) getNetworkFromStore(nid string) *network {
-	if d.store == nil {
-		return nil
-	}
-
-	n := &network{id: nid}
-	if err := d.store.GetObject(datastore.Key(n.Key()...), n); err != nil {
-		return nil
-	}
-
-	return n
-}
-
 func (n *network) sandbox() osl.Sandbox {
 	n.Lock()
 	defer n.Unlock()
@@ -926,12 +891,6 @@ func (n *network) vxlanID(s *subnet) uint32 {
 	return s.vni
 }
 
-func (n *network) setVxlanID(s *subnet, vni uint32) {
-	n.Lock()
-	s.vni = vni
-	n.Unlock()
-}
-
 func (n *network) Key() []string {
 	return []string{"overlay", "network", n.id}
 }
@@ -1047,14 +1006,6 @@ func (n *network) DataScope() string {
 	return datastore.GlobalScope
 }
 
-func (n *network) writeToStore() error {
-	if n.driver.store == nil {
-		return nil
-	}
-
-	return n.driver.store.PutObjectAtomic(n)
-}
-
 func (n *network) releaseVxlanID() ([]uint32, error) {
 	n.Lock()
 	nSubnets := len(n.subnets)
@@ -1063,17 +1014,6 @@ func (n *network) releaseVxlanID() ([]uint32, error) {
 		return nil, nil
 	}
 
-	if n.driver.store != nil {
-		if err := n.driver.store.DeleteObjectAtomic(n); err != nil {
-			if err == datastore.ErrKeyModified || err == datastore.ErrKeyNotFound {
-				// In both the above cases we can safely assume that the key has been removed by some other
-				// instance and so simply get out of here
-				return nil, nil
-			}
-
-			return nil, fmt.Errorf("failed to delete network to vxlan id map: %v", err)
-		}
-	}
 	var vnis []uint32
 	n.Lock()
 	for _, s := range n.subnets {
@@ -1096,35 +1036,7 @@ func (n *network) obtainVxlanID(s *subnet) error {
 	if n.vxlanID(s) != 0 {
 		return nil
 	}
-
-	if n.driver.store == nil {
-		return fmt.Errorf("no valid vxlan id and no datastore configured, cannot obtain vxlan id")
-	}
-
-	for {
-		if err := n.driver.store.GetObject(datastore.Key(n.Key()...), n); err != nil {
-			return fmt.Errorf("getting network %q from datastore failed %v", n.id, err)
-		}
-
-		if n.vxlanID(s) == 0 {
-			vxlanID, err := n.driver.vxlanIdm.GetID(true)
-			if err != nil {
-				return fmt.Errorf("failed to allocate vxlan id: %v", err)
-			}
-
-			n.setVxlanID(s, uint32(vxlanID))
-			if err := n.writeToStore(); err != nil {
-				n.driver.vxlanIdm.Release(uint64(n.vxlanID(s)))
-				n.setVxlanID(s, 0)
-				if err == datastore.ErrKeyModified {
-					continue
-				}
-				return fmt.Errorf("network %q failed to update data store: %v", n.id, err)
-			}
-			return nil
-		}
-		return nil
-	}
+	return fmt.Errorf("no valid vxlan id and no datastore configured, cannot obtain vxlan id")
 }
 
 // contains return true if the passed ip belongs to one the network's

libnetwork/drivers/overlay/overlay.go

@@ -25,8 +25,6 @@ const (
 	networkType  = "overlay"
 	vethPrefix   = "veth"
 	vethLen      = len(vethPrefix) + 7
-	vxlanIDStart = 256
-	vxlanIDEnd   = (1 << 24) - 1
 	vxlanEncap   = 50
 	secureOption = "encrypted"
 )
@@ -45,7 +43,6 @@ type driver struct {
 	secMap           *encrMap
 	serfInstance     *serf.Serf
 	networks         networkTable
-	store            datastore.DataStore
 	localStore       datastore.DataStore
 	vxlanIdm         *idm.Idm
 	initOS           sync.Once
@@ -71,18 +68,6 @@ func Register(r driverapi.Registerer, config map[string]interface{}) error {
 		config: config,
 	}
 
-	if data, ok := config[netlabel.GlobalKVClient]; ok {
-		var err error
-		dsc, ok := data.(discoverapi.DatastoreConfigData)
-		if !ok {
-			return types.InternalErrorf("incorrect data in datastore configuration: %v", data)
-		}
-		d.store, err = datastore.NewDataStoreFromConfig(dsc)
-		if err != nil {
-			return types.InternalErrorf("failed to initialize data store: %v", err)
-		}
-	}
-
 	if data, ok := config[netlabel.LocalKVClient]; ok {
 		var err error
 		dsc, ok := data.(discoverapi.DatastoreConfigData)
@@ -171,32 +156,6 @@ func (d *driver) configure() error {
 	// Apply OS specific kernel configs if needed
 	d.initOS.Do(applyOStweaks)
 
-	if d.store == nil {
-		return nil
-	}
-
-	if d.vxlanIdm == nil {
-		return d.initializeVxlanIdm()
-	}
-
-	return nil
-}
-
-func (d *driver) initializeVxlanIdm() error {
-	var err error
-
-	initVxlanIdm <- true
-	defer func() { <-initVxlanIdm }()
-
-	if d.vxlanIdm != nil {
-		return nil
-	}
-
-	d.vxlanIdm, err = idm.New(d.store, "vxlan-id", vxlanIDStart, vxlanIDEnd)
-	if err != nil {
-		return fmt.Errorf("failed to initialize vxlan id manager: %v", err)
-	}
-
 	return nil
 }
 
@@ -208,25 +167,6 @@ func (d *driver) IsBuiltIn() bool {
 	return true
 }
 
-func validateSelf(node string) error {
-	advIP := net.ParseIP(node)
-	if advIP == nil {
-		return fmt.Errorf("invalid self address (%s)", node)
-	}
-
-	addrs, err := net.InterfaceAddrs()
-	if err != nil {
-		return fmt.Errorf("Unable to get interface addresses %v", err)
-	}
-	for _, addr := range addrs {
-		ip, _, err := net.ParseCIDR(addr.String())
-		if err == nil && ip.Equal(advIP) {
-			return nil
-		}
-	}
-	return fmt.Errorf("Multi-Host overlay networking requires cluster-advertise(%s) to be configured with a local ip-address that is reachable within the cluster", advIP.String())
-}
-
 func (d *driver) nodeJoin(advertiseAddress, bindAddress string, self bool) {
 	if self && !d.isSerfAlive() {
 		d.Lock()
@@ -239,22 +179,6 @@ func (d *driver) nodeJoin(advertiseAddress, bindAddress string, self bool) {
 		d.localJoinOnce.Do(func() {
 			d.peerDBUpdateSelf()
 		})
-
-		// If there is no cluster store there is no need to start serf.
-		if d.store != nil {
-			if err := validateSelf(advertiseAddress); err != nil {
-				logrus.Warn(err.Error())
-			}
-			err := d.serfInit()
-			if err != nil {
-				logrus.Errorf("initializing serf instance failed: %v", err)
-				d.Lock()
-				d.advertiseAddress = ""
-				d.bindAddress = ""
-				d.Unlock()
-				return
-			}
-		}
 	}
 
 	d.Lock()

libnetwork/drivers/overlay/overlay_test.go

@@ -128,27 +128,6 @@ func TestOverlayFiniWithoutConfig(t *testing.T) {
 	cleanupDriver(t, dt)
 }
 
-func TestOverlayConfig(t *testing.T) {
-	dt := setupDriver(t)
-
-	time.Sleep(1 * time.Second)
-
-	d := dt.d
-	if d.notifyCh == nil {
-		t.Fatal("Driver notify channel wasn't initialized after Config method")
-	}
-
-	if d.exitCh == nil {
-		t.Fatal("Driver serfloop exit channel wasn't initialized after Config method")
-	}
-
-	if d.serfInstance == nil {
-		t.Fatal("Driver serfinstance  hasn't been initialized after Config method")
-	}
-
-	cleanupDriver(t, dt)
-}
-
 func TestOverlayType(t *testing.T) {
 	dt := &driverTester{t: t}
 	if err := Register(dt, nil); err != nil {