libnw/ipamutils: make local defaults immutable

ConfigLocalScopeDefaultNetworks is now dead code, thank goodness! Make
sure it stays dead by deleting the function. Refactor package ipamutils
to simplify things given its newly-reduced (ahem) scope.

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

libnetwork/ipamutils/utils.go

@@ -8,12 +8,12 @@ import (
 )
 
 var (
-	// PredefinedLocalScopeDefaultNetworks contains a list of 31 IPv4 private networks with host size 16 and 12
+	// predefinedLocalScopeDefaultNetworks contains a list of 31 IPv4 private networks with host size 16 and 12
 	// (172.17-31.x.x/16, 192.168.x.x/20) which do not overlap with the networks in `PredefinedGlobalScopeDefaultNetworks`
-	PredefinedLocalScopeDefaultNetworks []*net.IPNet
-	// PredefinedGlobalScopeDefaultNetworks contains a list of 64K IPv4 private networks with host size 8
+	predefinedLocalScopeDefaultNetworks []*net.IPNet
+	// predefinedGlobalScopeDefaultNetworks contains a list of 64K IPv4 private networks with host size 8
 	// (10.x.x.x/24) which do not overlap with the networks in `PredefinedLocalScopeDefaultNetworks`
-	PredefinedGlobalScopeDefaultNetworks []*net.IPNet
+	predefinedGlobalScopeDefaultNetworks []*net.IPNet
 	mutex                                sync.Mutex
 	localScopeDefaultNetworks            = []*NetworkToSplit{{"172.17.0.0/16", 16}, {"172.18.0.0/16", 16}, {"172.19.0.0/16", 16},
 		{"172.20.0.0/14", 16}, {"172.24.0.0/14", 16}, {"172.28.0.0/14", 16},
@@ -33,57 +33,41 @@ type NetworkToSplit struct {
 
 func init() {
 	var err error
-	if PredefinedGlobalScopeDefaultNetworks, err = SplitNetworks(globalScopeDefaultNetworks); err != nil {
+	if predefinedGlobalScopeDefaultNetworks, err = SplitNetworks(globalScopeDefaultNetworks); err != nil {
 		panic("failed to initialize the global scope default address pool: " + err.Error())
 	}
 
-	if PredefinedLocalScopeDefaultNetworks, err = SplitNetworks(localScopeDefaultNetworks); err != nil {
+	if predefinedLocalScopeDefaultNetworks, err = SplitNetworks(localScopeDefaultNetworks); err != nil {
 		panic("failed to initialize the local scope default address pool: " + err.Error())
 	}
 }
 
-// configDefaultNetworks configures local as well global default pool based on input
-func configDefaultNetworks(defaultAddressPool []*NetworkToSplit, result *[]*net.IPNet) error {
+// ConfigGlobalScopeDefaultNetworks configures global default pool.
+// Ideally this will be called from SwarmKit as part of swarm init
+func ConfigGlobalScopeDefaultNetworks(defaultAddressPool []*NetworkToSplit) error {
+	if defaultAddressPool == nil {
+		return nil
+	}
 	mutex.Lock()
 	defer mutex.Unlock()
 	defaultNetworks, err := SplitNetworks(defaultAddressPool)
 	if err != nil {
 		return err
 	}
-	*result = defaultNetworks
+	predefinedGlobalScopeDefaultNetworks = defaultNetworks
 	return nil
 }
 
-// GetGlobalScopeDefaultNetworks returns PredefinedGlobalScopeDefaultNetworks
+// GetGlobalScopeDefaultNetworks returns a copy of the global-sopce network list.
 func GetGlobalScopeDefaultNetworks() []*net.IPNet {
 	mutex.Lock()
 	defer mutex.Unlock()
-	return PredefinedGlobalScopeDefaultNetworks
+	return append([]*net.IPNet(nil), predefinedGlobalScopeDefaultNetworks...)
 }
 
-// GetLocalScopeDefaultNetworks returns PredefinedLocalScopeDefaultNetworks
+// GetLocalScopeDefaultNetworks returns a copy of the default local-scope network list.
 func GetLocalScopeDefaultNetworks() []*net.IPNet {
-	mutex.Lock()
-	defer mutex.Unlock()
-	return PredefinedLocalScopeDefaultNetworks
-}
-
-// ConfigGlobalScopeDefaultNetworks configures global default pool.
-// Ideally this will be called from SwarmKit as part of swarm init
-func ConfigGlobalScopeDefaultNetworks(defaultAddressPool []*NetworkToSplit) error {
-	if defaultAddressPool == nil {
-		defaultAddressPool = globalScopeDefaultNetworks
-	}
-	return configDefaultNetworks(defaultAddressPool, &PredefinedGlobalScopeDefaultNetworks)
-}
-
-// ConfigLocalScopeDefaultNetworks configures local default pool.
-// Ideally this will be called during libnetwork init
-func ConfigLocalScopeDefaultNetworks(defaultAddressPool []*NetworkToSplit) error {
-	if defaultAddressPool == nil {
-		return nil
-	}
-	return configDefaultNetworks(defaultAddressPool, &PredefinedLocalScopeDefaultNetworks)
+	return append([]*net.IPNet(nil), predefinedLocalScopeDefaultNetworks...)
 }
 
 // SplitNetworks takes a slice of networks, split them accordingly and returns them

libnetwork/ipamutils/utils_test.go

@@ -44,13 +44,13 @@ func initGlobalScopeNetworks() []*net.IPNet {
 }
 
 func TestDefaultNetwork(t *testing.T) {
-	for _, nw := range PredefinedGlobalScopeDefaultNetworks {
+	for _, nw := range GetGlobalScopeDefaultNetworks() {
 		if ones, bits := nw.Mask.Size(); bits != 32 || ones != 24 {
 			t.Fatalf("Unexpected size for network in granular list: %v", nw)
 		}
 	}
 
-	for _, nw := range PredefinedLocalScopeDefaultNetworks {
+	for _, nw := range GetLocalScopeDefaultNetworks() {
 		if ones, bits := nw.Mask.Size(); bits != 32 || (ones != 20 && ones != 16) {
 			t.Fatalf("Unexpected size for network in broad list: %v", nw)
 		}
@@ -61,7 +61,7 @@ func TestDefaultNetwork(t *testing.T) {
 	for _, v := range originalBroadNets {
 		m[v.String()] = true
 	}
-	for _, nw := range PredefinedLocalScopeDefaultNetworks {
+	for _, nw := range GetLocalScopeDefaultNetworks() {
 		_, ok := m[nw.String()]
 		assert.Check(t, ok)
 		delete(m, nw.String())
@@ -75,7 +75,7 @@ func TestDefaultNetwork(t *testing.T) {
 	for _, v := range originalGranularNets {
 		m[v.String()] = true
 	}
-	for _, nw := range PredefinedGlobalScopeDefaultNetworks {
+	for _, nw := range GetGlobalScopeDefaultNetworks() {
 		_, ok := m[nw.String()]
 		assert.Check(t, ok)
 		delete(m, nw.String())
@@ -93,7 +93,7 @@ func TestConfigGlobalScopeDefaultNetworks(t *testing.T) {
 	for _, v := range originalGlobalScopeNetworks {
 		m[v.String()] = true
 	}
-	for _, nw := range PredefinedGlobalScopeDefaultNetworks {
+	for _, nw := range GetGlobalScopeDefaultNetworks() {
 		_, ok := m[nw.String()]
 		assert.Check(t, ok)
 		delete(m, nw.String())
@@ -101,17 +101,3 @@ func TestConfigGlobalScopeDefaultNetworks(t *testing.T) {
 
 	assert.Check(t, is.Len(m, 0))
 }
-
-func TestInitAddressPools(t *testing.T) {
-	err := ConfigLocalScopeDefaultNetworks([]*NetworkToSplit{{"172.80.0.0/16", 24}, {"172.90.0.0/16", 24}})
-	assert.NilError(t, err)
-
-	// Check for Random IPAddresses in PredefinedLocalScopeDefaultNetworks  ex: first , last and middle
-	assert.Check(t, is.Len(PredefinedLocalScopeDefaultNetworks, 512), "Failed to find PredefinedLocalScopeDefaultNetworks")
-	assert.Check(t, is.Equal(PredefinedLocalScopeDefaultNetworks[0].String(), "172.80.0.0/24"))
-	assert.Check(t, is.Equal(PredefinedLocalScopeDefaultNetworks[127].String(), "172.80.127.0/24"))
-	assert.Check(t, is.Equal(PredefinedLocalScopeDefaultNetworks[255].String(), "172.80.255.0/24"))
-	assert.Check(t, is.Equal(PredefinedLocalScopeDefaultNetworks[256].String(), "172.90.0.0/24"))
-	assert.Check(t, is.Equal(PredefinedLocalScopeDefaultNetworks[383].String(), "172.90.127.0/24"))
-	assert.Check(t, is.Equal(PredefinedLocalScopeDefaultNetworks[511].String(), "172.90.255.0/24"))
-}

libnetwork/netutils/utils_linux_test.go

@@ -249,13 +249,13 @@ func TestUtilGenerateRandomMAC(t *testing.T) {
 func TestNetworkRequest(t *testing.T) {
 	defer testutils.SetupTestOSContext(t)()
 
-	nw, err := FindAvailableNetwork(ipamutils.PredefinedLocalScopeDefaultNetworks)
+	nw, err := FindAvailableNetwork(ipamutils.GetLocalScopeDefaultNetworks())
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	var found bool
-	for _, exp := range ipamutils.PredefinedLocalScopeDefaultNetworks {
+	for _, exp := range ipamutils.GetLocalScopeDefaultNetworks() {
 		if types.CompareIPNet(exp, nw) {
 			found = true
 			break
@@ -266,13 +266,13 @@ func TestNetworkRequest(t *testing.T) {
 		t.Fatalf("Found unexpected broad network %s", nw)
 	}
 
-	nw, err = FindAvailableNetwork(ipamutils.PredefinedGlobalScopeDefaultNetworks)
+	nw, err = FindAvailableNetwork(ipamutils.GetGlobalScopeDefaultNetworks())
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	found = false
-	for _, exp := range ipamutils.PredefinedGlobalScopeDefaultNetworks {
+	for _, exp := range ipamutils.GetGlobalScopeDefaultNetworks() {
 		if types.CompareIPNet(exp, nw) {
 			found = true
 			break
@@ -290,7 +290,7 @@ func TestNetworkRequest(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	nw, err = FindAvailableNetwork(ipamutils.PredefinedLocalScopeDefaultNetworks)
+	nw, err = FindAvailableNetwork(ipamutils.GetLocalScopeDefaultNetworks())
 	if err != nil {
 		t.Fatal(err)
 	}