libnetwork: open-code updating svc records

Inline the tortured logic for deciding when to skip updating the svc
records to give us a fighting chance at deciphering the logic behind the
logic and spotting logic bugs.

Update the service records synchronously. The only potential for issues
is if this change introduces deadlocks, which should be fixed by
restrucuting the mutexes rather than papering over the issue with
sketchy hacks like deferring the operation to a goroutine.

Signed-off-by: Cory Snider <csnider@mirantis.com>

libnetwork/endpoint.go

@@ -12,6 +12,7 @@ import (
 	"github.com/docker/docker/libnetwork/ipamapi"
 	"github.com/docker/docker/libnetwork/netlabel"
 	"github.com/docker/docker/libnetwork/options"
+	"github.com/docker/docker/libnetwork/scope"
 	"github.com/docker/docker/libnetwork/types"
 )
 
@@ -456,9 +457,10 @@ func (ep *Endpoint) sbJoin(sb *Sandbox, options ...EndpointOption) (err error) {
 		}
 	}()
 
-	// Watch for service records
 	if !n.getController().isAgent() {
-		n.getController().watchSvcRecord(ep)
+		if !n.getController().isSwarmNode() || n.Scope() != scope.Swarm || !n.driverIsMultihost() {
+			n.updateSvcRecord(ep, true)
+		}
 	}
 
 	// Do not update hosts file with internal networks endpoint IP
@@ -803,8 +805,9 @@ func (ep *Endpoint) Delete(force bool) error {
 		}
 	}()
 
-	// unwatch for service records
-	n.getController().unWatchSvcRecord(ep)
+	if !n.getController().isSwarmNode() || n.Scope() != scope.Swarm || !n.driverIsMultihost() {
+		n.updateSvcRecord(ep, false)
+	}
 
 	if err = ep.deleteEndpoint(force); err != nil && !force {
 		return err

libnetwork/network.go

@@ -1225,13 +1225,14 @@ func (n *Network) createEndpoint(name string, options ...EndpointOption) (*Endpo
 		return nil, err
 	}
 
-	// Watch for service records
-	n.getController().watchSvcRecord(ep)
-	defer func() {
-		if err != nil {
-			n.getController().unWatchSvcRecord(ep)
-		}
-	}()
+	if !n.getController().isSwarmNode() || n.Scope() != scope.Swarm || !n.driverIsMultihost() {
+		n.updateSvcRecord(ep, true)
+		defer func() {
+			if err != nil {
+				n.updateSvcRecord(ep, false)
+			}
+		}()
+	}
 
 	// Increment endpoint count to indicate completion of endpoint addition
 	if err = n.getEpCnt().IncEndpointCnt(); err != nil {

libnetwork/sandbox_store.go

@@ -278,9 +278,11 @@ func (c *Controller) sandboxCleanup(activeSandboxes map[string]interface{}) erro
 		}
 
 		for _, ep := range sb.endpoints {
-			// Watch for service records
 			if !c.isAgent() {
-				c.watchSvcRecord(ep)
+				n := ep.getNetwork()
+				if !c.isSwarmNode() || n.Scope() != scope.Swarm || !n.driverIsMultihost() {
+					n.updateSvcRecord(ep, true)
+				}
 			}
 		}
 	}

libnetwork/store.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/containerd/log"
 	"github.com/docker/docker/libnetwork/datastore"
-	"github.com/docker/docker/libnetwork/scope"
 )
 
 func (c *Controller) initStores() error {
@@ -184,32 +183,6 @@ retry:
 	return nil
 }
 
-func (c *Controller) watchSvcRecord(ep *Endpoint) {
-	go c.processEndpointCreate(ep)
-}
-
-func (c *Controller) unWatchSvcRecord(ep *Endpoint) {
-	go c.processEndpointDelete(ep)
-}
-
-func (c *Controller) processEndpointCreate(ep *Endpoint) {
-	n := ep.getNetwork()
-	if c.isSwarmNode() && n.Scope() == scope.Swarm && n.driverIsMultihost() {
-		return
-	}
-
-	n.updateSvcRecord(ep, true)
-}
-
-func (c *Controller) processEndpointDelete(ep *Endpoint) {
-	n := ep.getNetwork()
-	if c.isSwarmNode() && n.Scope() == scope.Swarm && n.driverIsMultihost() {
-		return
-	}
-
-	n.updateSvcRecord(ep, false)
-}
-
 func (c *Controller) networkCleanup() {
 	for _, n := range c.getNetworksFromStore() {
 		if n.inDelete {