libnet/ipam: default-address-pools as Register arg

Prior to this change, daemon's `default-address-pools` param would
be passed to `SetDefaultIPAddressPool()` to set a global var named
`defaultAddressPool`. This var would then be retrieved during the
`default` IPAM driver registration. Both steps were executed in
close succession during libnet's controller initialization.

This change removes the global var and just pass the user-defined
`default-address-pools` to the `default` driver's `Register` fn.

Signed-off-by: Albin Kerouanton <albinker@gmail.com>

libnetwork/cnmallocator/drivers_ipam.go

@@ -40,13 +40,11 @@ func initIPAMDrivers(r ipamapi.Registerer, netConfig *networkallocator.Config) e
 		log.G(context.TODO()).Infof("Swarm initialized global default address pool to: " + str.String())
 	}
 
-	for _, fn := range [](func(ipamapi.Registerer) error){
-		builtinIpam.Register,
-		nullIpam.Register,
-	} {
-		if err := fn(r); err != nil {
-			return err
-		}
+	if err := builtinIpam.Register(r, []*ipamutils.NetworkToSplit(nil)); err != nil {
+		return err
+	}
+	if err := nullIpam.Register(r); err != nil {
+		return err
 	}
 
 	return nil

libnetwork/drivers_ipam.go

@@ -10,21 +10,11 @@ import (
 )
 
 func initIPAMDrivers(r ipamapi.Registerer, pg plugingetter.PluginGetter, addressPool []*ipamutils.NetworkToSplit) error {
-	// TODO: pass address pools as arguments to builtinIpam.Init instead of
-	// indirectly through global mutable state. Swarmkit references that
-	// function so changing its signature breaks the build.
-	if err := builtinIpam.SetDefaultIPAddressPool(addressPool); err != nil {
+	if err := builtinIpam.Register(r, addressPool); err != nil {
 		return err
 	}
-
-	for _, fn := range [](func(ipamapi.Registerer) error){
-		builtinIpam.Register,
-		nullIpam.Register,
-	} {
-		if err := fn(r); err != nil {
-			return err
-		}
+	if err := nullIpam.Register(r); err != nil {
+		return err
 	}
-
 	return remoteIpam.Register(r, pg)
 }

libnetwork/drvregistry/ipams_test.go

@@ -9,6 +9,7 @@ import (
 	builtinIpam "github.com/docker/docker/libnetwork/ipams/builtin"
 	nullIpam "github.com/docker/docker/libnetwork/ipams/null"
 	remoteIpam "github.com/docker/docker/libnetwork/ipams/remote"
+	"github.com/docker/docker/libnetwork/ipamutils"
 	"gotest.tools/v3/assert"
 	is "gotest.tools/v3/assert/cmp"
 )
@@ -16,7 +17,7 @@ import (
 func getNewIPAMs(t *testing.T) *IPAMs {
 	r := &IPAMs{}
 
-	assert.Assert(t, builtinIpam.Register(r))
+	assert.Assert(t, builtinIpam.Register(r, []*ipamutils.NetworkToSplit(nil)))
 	assert.Assert(t, remoteIpam.Register(r, nil))
 	assert.Assert(t, nullIpam.Register(r))
 

libnetwork/ipams/builtin/builtin.go

@@ -1,26 +1,25 @@
 package builtin
 
 import (
-	"net"
-
 	"github.com/docker/docker/libnetwork/ipam"
 	"github.com/docker/docker/libnetwork/ipamapi"
 	"github.com/docker/docker/libnetwork/ipamutils"
 )
 
-// defaultAddressPool Stores user configured subnet list
-var defaultAddressPool []*net.IPNet
-
-// registerBuiltin registers the built-in ipam driver with libnetwork.
-func registerBuiltin(ic ipamapi.Registerer) error {
-	var localAddressPool []*net.IPNet
-	if len(defaultAddressPool) > 0 {
-		localAddressPool = append([]*net.IPNet(nil), defaultAddressPool...)
-	} else {
-		localAddressPool = ipamutils.GetLocalScopeDefaultNetworks()
+// registerBuiltin registers the built-in ipam driver with libnetwork. It takes
+// an optional addressPools containing the list of user-defined address pools
+// used by the local address space (ie. daemon's default-address-pools parameter).
+func registerBuiltin(ic ipamapi.Registerer, addressPools []*ipamutils.NetworkToSplit) error {
+	localAddressPools := ipamutils.GetLocalScopeDefaultNetworks()
+	if len(addressPools) > 0 {
+		var err error
+		localAddressPools, err = ipamutils.SplitNetworks(addressPools)
+		if err != nil {
+			return err
+		}
 	}
 
-	a, err := ipam.NewAllocator(localAddressPool, ipamutils.GetGlobalScopeDefaultNetworks())
+	a, err := ipam.NewAllocator(localAddressPools, ipamutils.GetGlobalScopeDefaultNetworks())
 	if err != nil {
 		return err
 	}
@@ -29,13 +28,3 @@ func registerBuiltin(ic ipamapi.Registerer) error {
 
 	return ic.RegisterIpamDriverWithCapabilities(ipamapi.DefaultIPAM, a, cps)
 }
-
-// SetDefaultIPAddressPool stores default address pool.
-func SetDefaultIPAddressPool(addressPool []*ipamutils.NetworkToSplit) error {
-	nets, err := ipamutils.SplitNetworks(addressPool)
-	if err != nil {
-		return err
-	}
-	defaultAddressPool = nets
-	return nil
-}

libnetwork/ipams/builtin/builtin_unix.go

@@ -4,9 +4,10 @@ package builtin
 
 import (
 	"github.com/docker/docker/libnetwork/ipamapi"
+	"github.com/docker/docker/libnetwork/ipamutils"
 )
 
 // Register registers the built-in ipam service with libnetwork.
-func Register(r ipamapi.Registerer) error {
-	return registerBuiltin(r)
+func Register(r ipamapi.Registerer, addressPools []*ipamutils.NetworkToSplit) error {
+	return registerBuiltin(r, addressPools)
 }

libnetwork/ipams/builtin/builtin_windows.go

@@ -5,11 +5,12 @@ package builtin
 import (
 	"github.com/docker/docker/libnetwork/ipamapi"
 	"github.com/docker/docker/libnetwork/ipams/windowsipam"
+	"github.com/docker/docker/libnetwork/ipamutils"
 )
 
 // Register registers the built-in ipam services with libnetwork.
-func Register(r ipamapi.Registerer) error {
-	if err := registerBuiltin(r); err != nil {
+func Register(r ipamapi.Registerer, addressPools []*ipamutils.NetworkToSplit) error {
+	if err := registerBuiltin(r, addressPools); err != nil {
 		return err
 	}