fix(network): Generate prefixes to ensure proper lexicographical ordering

In order for networkd to properly configure the network interfaces, the configs must be
prefixed to ensure that they load in the correct order (parent interfaces have a lower
prefix than their children).

network/interface.go

@@ -7,15 +7,23 @@ import (
 
 type InterfaceGenerator interface {
 	Name() string
+	Filename() string
 	Netdev() string
 	Link() string
 	Network() string
 }
 
+type networkInterface interface {
+	InterfaceGenerator
+	Children() []networkInterface
+	setConfigDepth(int)
+}
+
 type logicalInterface struct {
 	name        string
 	config      configMethod
-	children []InterfaceGenerator
+	children    []networkInterface
+	configDepth int
 }
 
 func (i *logicalInterface) Network() string {
@@ -52,6 +60,18 @@ func (i *logicalInterface) Link() string {
 	return ""
 }
 
+func (i *logicalInterface) Filename() string {
+	return fmt.Sprintf("%02x-%s", i.configDepth, i.name)
+}
+
+func (i *logicalInterface) Children() []networkInterface {
+	return i.children
+}
+
+func (i *logicalInterface) setConfigDepth(depth int) {
+	i.configDepth = depth
+}
+
 type physicalInterface struct {
 	logicalInterface
 }
@@ -104,8 +124,20 @@ func (v *vlanInterface) Netdev() string {
 }
 
 func buildInterfaces(stanzas []*stanzaInterface) []InterfaceGenerator {
-	interfaceMap := make(map[string]InterfaceGenerator)
+	interfaceMap := createInterfaces(stanzas)
+	linkAncestors(interfaceMap)
+	markConfigDepths(interfaceMap)
 
+	interfaces := make([]InterfaceGenerator, 0, len(interfaceMap))
+	for _, iface := range interfaceMap {
+		interfaces = append(interfaces, iface)
+	}
+
+	return interfaces
+}
+
+func createInterfaces(stanzas []*stanzaInterface) map[string]networkInterface {
+	interfaceMap := make(map[string]networkInterface)
 	for _, iface := range stanzas {
 		switch iface.kind {
 		case interfaceBond:
@@ -113,7 +145,7 @@ func buildInterfaces(stanzas []*stanzaInterface) []InterfaceGenerator {
 				logicalInterface{
 					name:     iface.name,
 					config:   iface.configMethod,
-					children: []InterfaceGenerator{},
+					children: []networkInterface{},
 				},
 				iface.options["slaves"],
 			}
@@ -123,7 +155,7 @@ func buildInterfaces(stanzas []*stanzaInterface) []InterfaceGenerator {
 						logicalInterface{
 							name:     slave,
 							config:   configMethodManual{},
-							children: []InterfaceGenerator{},
+							children: []networkInterface{},
 						},
 					}
 				}
@@ -137,7 +169,7 @@ func buildInterfaces(stanzas []*stanzaInterface) []InterfaceGenerator {
 				logicalInterface{
 					name:     iface.name,
 					config:   iface.configMethod,
-					children: []InterfaceGenerator{},
+					children: []networkInterface{},
 				},
 			}
 
@@ -151,7 +183,7 @@ func buildInterfaces(stanzas []*stanzaInterface) []InterfaceGenerator {
 						logicalInterface{
 							name:     rawDevice,
 							config:   configMethodManual{},
-							children: []InterfaceGenerator{},
+							children: []networkInterface{},
 						},
 					}
 				}
@@ -160,14 +192,17 @@ func buildInterfaces(stanzas []*stanzaInterface) []InterfaceGenerator {
 				logicalInterface{
 					name:     iface.name,
 					config:   iface.configMethod,
-					children: []InterfaceGenerator{},
+					children: []networkInterface{},
 				},
 				id,
 				rawDevice,
 			}
 		}
 	}
+	return interfaceMap
+}
 
+func linkAncestors(interfaceMap map[string]networkInterface) {
 	for _, iface := range interfaceMap {
 		switch i := iface.(type) {
 		case *vlanInterface:
@@ -192,11 +227,27 @@ func buildInterfaces(stanzas []*stanzaInterface) []InterfaceGenerator {
 			}
 		}
 	}
+}
 
-	interfaces := make([]InterfaceGenerator, 0, len(interfaceMap))
+func markConfigDepths(interfaceMap map[string]networkInterface) {
-	for _, iface := range interfaceMap {
+	rootInterfaceMap := make(map[string]networkInterface)
-		interfaces = append(interfaces, iface)
+	for k, v := range interfaceMap {
+		rootInterfaceMap[k] = v
 	}
 
-	return interfaces
+	for _, iface := range interfaceMap {
+		for _, child := range iface.Children() {
+			delete(rootInterfaceMap, child.Name())
+		}
+	}
+	for _, iface := range rootInterfaceMap {
+		setDepth(iface, 0)
+	}
+}
+
+func setDepth(iface networkInterface, depth int) {
+	iface.setConfigDepth(depth)
+	for _, child := range iface.Children() {
+		setDepth(child, depth+1)
+	}
 }

network/interface_test.go

@@ -30,7 +30,7 @@ func TestPhysicalInterfaceLink(t *testing.T) {
 func TestPhysicalInterfaceNetwork(t *testing.T) {
 	p := physicalInterface{logicalInterface{
 		name: "testname",
-		children: []InterfaceGenerator{
+		children: []networkInterface{
 			&bondInterface{
 				logicalInterface{
 					name: "testbond1",
@@ -96,7 +96,7 @@ func TestBondInterfaceNetwork(t *testing.T) {
 		logicalInterface{
 			name:   "testname",
 			config: configMethodDHCP{},
-			children: []InterfaceGenerator{
+			children: []networkInterface{
 				&bondInterface{
 					logicalInterface{
 						name: "testbond1",
@@ -251,7 +251,8 @@ func TestBuildInterfacesBlindBond(t *testing.T) {
 		logicalInterface{
 			name:        "bond0",
 			config:      configMethodManual{},
-			children: []InterfaceGenerator{},
+			children:    []networkInterface{},
+			configDepth: 1,
 		},
 		[]string{"eth0"},
 	}
@@ -259,7 +260,8 @@ func TestBuildInterfacesBlindBond(t *testing.T) {
 		logicalInterface{
 			name:        "eth0",
 			config:      configMethodManual{},
-			children: []InterfaceGenerator{bond0},
+			children:    []networkInterface{bond0},
+			configDepth: 0,
 		},
 	}
 	expect := []InterfaceGenerator{bond0, eth0}
@@ -286,7 +288,8 @@ func TestBuildInterfacesBlindVLAN(t *testing.T) {
 		logicalInterface{
 			name:        "vlan0",
 			config:      configMethodManual{},
-			children: []InterfaceGenerator{},
+			children:    []networkInterface{},
+			configDepth: 1,
 		},
 		0,
 		"eth0",
@@ -295,7 +298,8 @@ func TestBuildInterfacesBlindVLAN(t *testing.T) {
 		logicalInterface{
 			name:        "eth0",
 			config:      configMethodManual{},
-			children: []InterfaceGenerator{vlan0},
+			children:    []networkInterface{vlan0},
+			configDepth: 0,
 		},
 	}
 	expect := []InterfaceGenerator{eth0, vlan0}
@@ -357,7 +361,8 @@ func TestBuildInterfaces(t *testing.T) {
 		logicalInterface{
 			name:        "vlan1",
 			config:      configMethodManual{},
-			children: []InterfaceGenerator{},
+			children:    []networkInterface{},
+			configDepth: 2,
 		},
 		1,
 		"bond0",
@@ -366,7 +371,8 @@ func TestBuildInterfaces(t *testing.T) {
 		logicalInterface{
 			name:        "vlan0",
 			config:      configMethodManual{},
-			children: []InterfaceGenerator{},
+			children:    []networkInterface{},
+			configDepth: 1,
 		},
 		0,
 		"eth0",
@@ -375,7 +381,8 @@ func TestBuildInterfaces(t *testing.T) {
 		logicalInterface{
 			name:        "bond1",
 			config:      configMethodManual{},
-			children: []InterfaceGenerator{},
+			children:    []networkInterface{},
+			configDepth: 2,
 		},
 		[]string{"bond0"},
 	}
@@ -383,7 +390,8 @@ func TestBuildInterfaces(t *testing.T) {
 		logicalInterface{
 			name:        "bond0",
 			config:      configMethodManual{},
-			children: []InterfaceGenerator{bond1, vlan1},
+			children:    []networkInterface{bond1, vlan1},
+			configDepth: 1,
 		},
 		[]string{"eth0"},
 	}
@@ -391,7 +399,8 @@ func TestBuildInterfaces(t *testing.T) {
 		logicalInterface{
 			name:        "eth0",
 			config:      configMethodManual{},
-			children: []InterfaceGenerator{bond0, vlan0},
+			children:    []networkInterface{bond0, vlan0},
+			configDepth: 0,
 		},
 	}
 	expect := []InterfaceGenerator{eth0, bond0, bond1, vlan0, vlan1}
@@ -399,3 +408,19 @@ func TestBuildInterfaces(t *testing.T) {
 		t.FailNow()
 	}
 }
+
+func TestFilename(t *testing.T) {
+	for _, tt := range []struct {
+		i logicalInterface
+		f string
+	}{
+		{logicalInterface{name: "iface", configDepth: 0}, "00-iface"},
+		{logicalInterface{name: "iface", configDepth: 9}, "09-iface"},
+		{logicalInterface{name: "iface", configDepth: 10}, "0a-iface"},
+		{logicalInterface{name: "iface", configDepth: 53}, "35-iface"},
+	} {
+		if tt.i.Filename() != tt.f {
+			t.Fatalf("bad filename (%q): got %q, want %q", tt.i, tt.i.Filename(), tt.f)
+		}
+	}
+}

system/networkd.go

@@ -66,15 +66,15 @@ func restartNetworkd() error {
 
 func WriteNetworkdConfigs(interfaces []network.InterfaceGenerator) error {
 	for _, iface := range interfaces {
-		filename := path.Join(runtimeNetworkPath, fmt.Sprintf("%s.netdev", iface.Name()))
+		filename := path.Join(runtimeNetworkPath, fmt.Sprintf("%s.netdev", iface.Filename()))
 		if err := writeConfig(filename, iface.Netdev()); err != nil {
 			return err
 		}
-		filename = path.Join(runtimeNetworkPath, fmt.Sprintf("%s.link", iface.Name()))
+		filename = path.Join(runtimeNetworkPath, fmt.Sprintf("%s.link", iface.Filename()))
 		if err := writeConfig(filename, iface.Link()); err != nil {
 			return err
 		}
-		filename = path.Join(runtimeNetworkPath, fmt.Sprintf("%s.network", iface.Name()))
+		filename = path.Join(runtimeNetworkPath, fmt.Sprintf("%s.network", iface.Filename()))
 		if err := writeConfig(filename, iface.Network()); err != nil {
 			return err
 		}