scheduler: do network feasibility checking for system jobs

scheduler/feasible.go

@@ -381,7 +381,11 @@ func (c *NetworkChecker) hasNetwork(option *structs.Node) bool {
 	}
 
 	for _, nw := range option.NodeResources.Networks {
-		if nw.Mode == c.networkMode {
+		mode := nw.Mode
+		if mode == "" {
+			mode = "host"
+		}
+		if mode == c.networkMode {
 			return true
 		}
 	}

scheduler/stack.go

@@ -183,6 +183,7 @@ type SystemStack struct {
 	taskGroupDevices     *DeviceChecker
 	taskGroupHostVolumes *HostVolumeChecker
 	taskGroupCSIVolumes  *CSIVolumeChecker
+	taskGroupNetwork     *NetworkChecker
 
 	distinctPropertyConstraint *DistinctPropertyIterator
 	binPack                    *BinPackIterator
@@ -220,14 +221,18 @@ func NewSystemStack(ctx Context) *SystemStack {
 	// Filter on task group devices
 	s.taskGroupDevices = NewDeviceChecker(ctx)
 
+	// Filter on available client networks
+	s.taskGroupNetwork = NewNetworkChecker(ctx)
+
 	// Create the feasibility wrapper which wraps all feasibility checks in
 	// which feasibility checking can be skipped if the computed node class has
 	// previously been marked as eligible or ineligible. Generally this will be
 	// checks that only needs to examine the single node to determine feasibility.
 	jobs := []FeasibilityChecker{s.jobConstraint}
 	tgs := []FeasibilityChecker{s.taskGroupDrivers, s.taskGroupConstraint,
 		s.taskGroupHostVolumes,
-		s.taskGroupDevices}
+		s.taskGroupDevices,
+		s.taskGroupNetwork}
 	avail := []FeasibilityChecker{s.taskGroupCSIVolumes}
 	s.wrappedChecks = NewFeasibilityWrapper(ctx, s.quota, jobs, tgs, avail)
 
@@ -285,6 +290,9 @@ func (s *SystemStack) Select(tg *structs.TaskGroup, options *SelectOptions) *Ran
 	s.taskGroupDevices.SetTaskGroup(tg)
 	s.taskGroupHostVolumes.SetVolumes(tg.Volumes)
 	s.taskGroupCSIVolumes.SetVolumes(tg.Volumes)
+	if len(tg.Networks) > 0 {
+		s.taskGroupNetwork.SetNetwork(tg.Networks[0])
+	}
 	s.wrappedChecks.SetTaskGroup(tg.Name)
 	s.distinctPropertyConstraint.SetTaskGroup(tg)
 	s.binPack.SetTaskGroup(tg)

scheduler/system_sched_test.go

@@ -1893,6 +1893,19 @@ func TestSystemSched_Preemption(t *testing.T) {
 					MBits:  1000,
 				},
 			},
+			NodeNetworks: []*structs.NodeNetworkResource{
+				{
+					Mode:   "host",
+					Device: "eth0",
+					Addresses: []structs.NodeNetworkAddress{
+						{
+							Family:  structs.NodeNetworkAF_IPv4,
+							Alias:   "default",
+							Address: "192.168.0.100",
+						},
+					},
+				},
+			},
 		}
 		require.NoError(t, h.State.UpsertNode(h.NextIndex(), node))
 		nodes = append(nodes, node)