Driver api refactor

Refactored the driver api so that is aligns well with the design
of endpoint lifecycle becoming decoupled from the container lifecycle.
Introduced go interfaces to obtain address information during CreateEndpoint.
Go interfaces are also used to get data from driver during join.
This sort of deisgn hides the libnetwork specific type details from drivers.

Another adjustment is to provide a list of interfaces during CreateEndpoint. The
goal of this is many-fold:
     * To indicate to the driver that IP address has been assigned by some other
       entity (like a user wanting to use their own static IP for an endpoint/container)
       and asking the driver to honor this. Driver may reject this configuration
       and return an error but it may not try to allocate an IP address and override
       the passed one.
     * To indicate to the driver that IP address has already been allocated once
       for this endpoint by an instance of the same driver in some docker host
       in the cluster and this is merely a notification about that endpoint and the
       allocated resources.
     * In case the list of interfaces is empty the driver is required to allocate and
       assign IP addresses for this endpoint.

Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>

endpoint.go

@@ -10,7 +10,6 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/pkg/ioutils"
-	"github.com/docker/libnetwork/driverapi"
 	"github.com/docker/libnetwork/etchosts"
 	"github.com/docker/libnetwork/netlabel"
 	"github.com/docker/libnetwork/netutils"
@@ -39,11 +38,11 @@ type Endpoint interface {
 	// the network resources populated in the sandbox
 	Leave(containerID string, options ...EndpointOption) error
 
-	// SandboxInfo returns the sandbox information for this endpoint.
-	SandboxInfo() *sandbox.Info
+	// Return certain operational data belonging to this endpoint
+	Info() EndpointInfo
 
-	// Info returns a collection of operational data related to this endpoint retrieved from the driver
-	Info() (map[string]interface{}, error)
+	// Info returns a collection of driver operational data related to this endpoint retrieved from the driver
+	DriverInfo() (map[string]interface{}, error)
 
 	// Delete and detaches this endpoint from the network.
 	Delete() error
@@ -104,12 +103,11 @@ type endpoint struct {
 	id            types.UUID
 	network       *network
 	sandboxInfo   *sandbox.Info
-	sandBox       sandbox.Sandbox
-	joinInfo      *driverapi.JoinInfo
+	iFaces        []*endpointInterface
+	joinInfo      *endpointJoinInfo
 	container     *containerInfo
 	exposedPorts  []netutils.TransportPort
 	generic       map[string]interface{}
-	context       map[string]interface{}
 	joinLeaveDone chan struct{}
 	sync.Mutex
 }
@@ -137,30 +135,6 @@ func (ep *endpoint) Network() string {
 	return ep.network.name
 }
 
-func (ep *endpoint) SandboxInfo() *sandbox.Info {
-	ep.Lock()
-	defer ep.Unlock()
-
-	if ep.sandboxInfo == nil {
-		return nil
-	}
-	return ep.sandboxInfo.GetCopy()
-}
-
-func (ep *endpoint) Info() (map[string]interface{}, error) {
-	ep.Lock()
-	network := ep.network
-	epid := ep.id
-	ep.Unlock()
-
-	network.Lock()
-	driver := network.driver
-	nid := network.id
-	network.Unlock()
-
-	return driver.EndpointInfo(nid, epid)
-}
-
 func (ep *endpoint) processOptions(options ...EndpointOption) {
 	ep.Lock()
 	defer ep.Unlock()
@@ -255,9 +229,13 @@ func (ep *endpoint) Join(containerID string, options ...EndpointOption) (*Contai
 			},
 		}}
 
+	ep.joinInfo = &endpointJoinInfo{}
+
 	container := ep.container
 	network := ep.network
 	epid := ep.id
+	joinInfo := ep.joinInfo
+	ifaces := ep.iFaces
 
 	ep.Unlock()
 	defer func() {
@@ -281,15 +259,11 @@ func (ep *endpoint) Join(containerID string, options ...EndpointOption) (*Contai
 		sboxKey = sandbox.GenerateKey("default")
 	}
 
-	joinInfo, err := driver.Join(nid, epid, sboxKey, container.config.generic)
+	err = driver.Join(nid, epid, sboxKey, ep, container.config.generic)
 	if err != nil {
 		return nil, err
 	}
 
-	ep.Lock()
-	ep.joinInfo = joinInfo
-	ep.Unlock()
-
 	err = ep.buildHostsFiles()
 	if err != nil {
 		return nil, err
@@ -315,24 +289,29 @@ func (ep *endpoint) Join(containerID string, options ...EndpointOption) (*Contai
 		}
 	}()
 
-	sinfo := ep.SandboxInfo()
-	if sinfo != nil {
-		for _, i := range sinfo.Interfaces {
-			err = sb.AddInterface(i)
-			if err != nil {
-				return nil, err
-			}
+	for _, i := range ifaces {
+		iface := &sandbox.Interface{
+			SrcName: i.srcName,
+			DstName: i.dstName,
+			Address: &i.addr,
 		}
-
-		err = sb.SetGateway(sinfo.Gateway)
+		if i.addrv6.IP.To16() != nil {
+			iface.AddressIPv6 = &i.addrv6
+		}
+		err = sb.AddInterface(iface)
 		if err != nil {
 			return nil, err
 		}
+	}
 
-		err = sb.SetGatewayIPv6(sinfo.GatewayIPv6)
-		if err != nil {
-			return nil, err
-		}
+	err = sb.SetGateway(joinInfo.gw)
+	if err != nil {
+		return nil, err
+	}
+
+	err = sb.SetGatewayIPv6(joinInfo.gw6)
+	if err != nil {
+		return nil, err
 	}
 
 	container.data.SandboxKey = sb.Key()
@@ -352,7 +331,6 @@ func (ep *endpoint) Leave(containerID string, options ...EndpointOption) error {
 	ep.Lock()
 	container := ep.container
 	n := ep.network
-	context := ep.context
 
 	if container == nil || container.id == "" ||
 		containerID == "" || container.id != containerID {
@@ -366,7 +344,6 @@ func (ep *endpoint) Leave(containerID string, options ...EndpointOption) error {
 		return err
 	}
 	ep.container = nil
-	ep.context = nil
 	ep.Unlock()
 
 	n.Lock()
@@ -374,16 +351,13 @@ func (ep *endpoint) Leave(containerID string, options ...EndpointOption) error {
 	ctrlr := n.ctrlr
 	n.Unlock()
 
-	err = driver.Leave(n.id, ep.id, context)
+	err = driver.Leave(n.id, ep.id)
 
-	sinfo := ep.SandboxInfo()
-	if sinfo != nil {
-		sb := ctrlr.sandboxGet(container.data.SandboxKey)
-		for _, i := range sinfo.Interfaces {
-			err = sb.RemoveInterface(i)
-			if err != nil {
-				logrus.Debugf("Remove interface failed: %v", err)
-			}
+	sb := ctrlr.sandboxGet(container.data.SandboxKey)
+	for _, i := range sb.Interfaces() {
+		err = sb.RemoveInterface(i)
+		if err != nil {
+			logrus.Debugf("Remove interface failed: %v", err)
 		}
 	}
 
@@ -435,6 +409,7 @@ func (ep *endpoint) buildHostsFiles() error {
 	ep.Lock()
 	container := ep.container
 	joinInfo := ep.joinInfo
+	ifaces := ep.iFaces
 	ep.Unlock()
 
 	if container == nil {
@@ -451,8 +426,8 @@ func (ep *endpoint) buildHostsFiles() error {
 		return err
 	}
 
-	if joinInfo != nil && joinInfo.HostsPath != "" {
-		content, err := ioutil.ReadFile(joinInfo.HostsPath)
+	if joinInfo != nil && joinInfo.hostsPath != "" {
+		content, err := ioutil.ReadFile(joinInfo.hostsPath)
 		if err != nil && !os.IsNotExist(err) {
 			return err
 		}
@@ -473,10 +448,8 @@ func (ep *endpoint) buildHostsFiles() error {
 	}
 
 	IP := ""
-	sinfo := ep.SandboxInfo()
-	if sinfo != nil && sinfo.Interfaces[0] != nil &&
-		sinfo.Interfaces[0].Address != nil {
-		IP = sinfo.Interfaces[0].Address.IP.String()
+	if len(ifaces) != 0 && ifaces[0] != nil {
+		IP = ifaces[0].addr.IP.String()
 	}
 
 	return etchosts.Build(container.config.hostsPath, IP, container.config.hostName,
@@ -749,12 +722,3 @@ func JoinOptionGeneric(generic map[string]interface{}) EndpointOption {
 		ep.container.config.generic = generic
 	}
 }
-
-// LeaveOptionGeneric function returns an option setter for Generic configuration
-// that is not managed by libNetwork but can be used by the Drivers during the call to
-// endpoint leave method. Container Labels are a good example.
-func LeaveOptionGeneric(context map[string]interface{}) EndpointOption {
-	return func(ep *endpoint) {
-		ep.context = context
-	}
-}