Introduce Sandbox entity

- Maps 1 to 1 with container's networking stack
- It holds container's specific nw options which
  before were incorrectly owned by Endpoint.
- Sandbox creation no longer coupled with Endpoint Join,
  sandbox and endpoint have now separate lifecycle.
- LeaveAll naturally replaced by Sandbox.Delete
- some pkg and file renaming in order to have clear
  mapping between structure name and entity ("sandbox")
- Revisited hosts and resolv.conf handling
- Removed from JoinInfo interface capability of setting hosts and resolv.conf paths
- Changed etchosts.Build() to first write the search domains and then the nameservers

Signed-off-by: Alessandro Boch <aboch@docker.com>

libnetwork/driverapi/driverapi.go

@@ -1,10 +1,6 @@
 package driverapi
 
-import (
-	"net"
-
-	"github.com/docker/libnetwork/types"
-)
+import "net"
 
 // NetworkPluginEndpointType represents the Endpoint Type used by Plugin system
 const NetworkPluginEndpointType = "NetworkDriver"
@@ -17,31 +13,31 @@ type Driver interface {
 	// CreateNetwork invokes the driver method to create a network passing
 	// the network id and network specific config. The config mechanism will
 	// eventually be replaced with labels which are yet to be introduced.
-	CreateNetwork(nid types.UUID, options map[string]interface{}) error
+	CreateNetwork(nid string, options map[string]interface{}) error
 
 	// DeleteNetwork invokes the driver method to delete network passing
 	// the network id.
-	DeleteNetwork(nid types.UUID) error
+	DeleteNetwork(nid string) error
 
 	// CreateEndpoint invokes the driver method to create an endpoint
 	// passing the network id, endpoint id endpoint information and driver
 	// specific config. The endpoint information can be either consumed by
 	// the driver or populated by the driver. The config mechanism will
 	// eventually be replaced with labels which are yet to be introduced.
-	CreateEndpoint(nid, eid types.UUID, epInfo EndpointInfo, options map[string]interface{}) error
+	CreateEndpoint(nid, eid string, epInfo EndpointInfo, options map[string]interface{}) error
 
 	// DeleteEndpoint invokes the driver method to delete an endpoint
 	// passing the network id and endpoint id.
-	DeleteEndpoint(nid, eid types.UUID) error
+	DeleteEndpoint(nid, eid string) error
 
 	// EndpointOperInfo retrieves from the driver the operational data related to the specified endpoint
-	EndpointOperInfo(nid, eid types.UUID) (map[string]interface{}, error)
+	EndpointOperInfo(nid, eid string) (map[string]interface{}, error)
 
 	// Join method is invoked when a Sandbox is attached to an endpoint.
-	Join(nid, eid types.UUID, sboxKey string, jinfo JoinInfo, options map[string]interface{}) error
+	Join(nid, eid string, sboxKey string, jinfo JoinInfo, options map[string]interface{}) error
 
 	// Leave method is invoked when a Sandbox detaches from an endpoint.
-	Leave(nid, eid types.UUID) error
+	Leave(nid, eid string) error
 
 	// Type returns the the type of this driver, the network type this driver manages
 	Type() string
@@ -107,12 +103,6 @@ type JoinInfo interface {
 	// AddStaticRoute adds a routes to the sandbox.
 	// It may be used in addtion to or instead of a default gateway (as above).
 	AddStaticRoute(destination *net.IPNet, routeType int, nextHop net.IP, interfaceID int) error
-
-	// SetHostsPath sets the overriding /etc/hosts path to use for the container.
-	SetHostsPath(string) error
-
-	// SetResolvConfPath sets the overriding /etc/resolv.conf path to use for the container.
-	SetResolvConfPath(string) error
 }
 
 // DriverCallback provides a Callback interface for Drivers into LibNetwork