Support subnet and iprange arguments on network create

plugin/ipam/driver.go

@@ -1,7 +1,9 @@
 package ipamplugin
 
 import (
+	"fmt"
 	"net"
+	"strings"
 
 	"github.com/docker/libnetwork/ipamapi"
 	"github.com/docker/libnetwork/netlabel"
@@ -29,14 +31,29 @@ func (i *ipam) GetDefaultAddressSpaces() (string, string, error) {
 	return "weavelocal", "weaveglobal", nil
 }
 
-func (i *ipam) RequestPool(addressSpace, pool, subPool string, options map[string]string, v6 bool) (string, *net.IPNet, map[string]string, error) {
+func (i *ipam) RequestPool(addressSpace, pool, subPool string, options map[string]string, v6 bool) (poolname string, subnet *net.IPNet, data map[string]string, err error) {
 	Log.Debugln("RequestPool", addressSpace, pool, subPool, options)
-	cidr, err := i.weave.DefaultSubnet()
-	Log.Debugln("RequestPool returning ", cidr, err)
+	defer func() { Log.Debugln("RequestPool returning", poolname, subnet, data, err) }()
+	if pool == "" {
+		subnet, err = i.weave.DefaultSubnet()
+	} else {
+		_, subnet, err = net.ParseCIDR(pool)
+	}
+	if err != nil {
+		return
+	}
+	iprange := subnet
+	if subPool != "" {
+		if _, iprange, err = net.ParseCIDR(subPool); err != nil {
+			return
+		}
+	}
+	// Cunningly-constructed pool "name" which gives us what we need later
+	poolname = strings.Join([]string{"weave", subnet.String(), iprange.String()}, "-")
 	// Pass back a fake "gateway address"; we don't actually use it,
 	// so just give the network address.
-	data := map[string]string{netlabel.Gateway: cidr.String()}
-	return "weavepool", cidr, data, err
+	data = map[string]string{netlabel.Gateway: subnet.String()}
+	return
 }
 
 func (i *ipam) ReleasePool(poolID string) error {
@@ -44,12 +61,32 @@ func (i *ipam) ReleasePool(poolID string) error {
 	return nil
 }
 
-func (i *ipam) RequestAddress(poolID string, address net.IP, options map[string]string) (*net.IPNet, map[string]string, error) {
+func (i *ipam) RequestAddress(poolID string, address net.IP, options map[string]string) (ip *net.IPNet, _ map[string]string, err error) {
 	Log.Debugln("RequestAddress", poolID, address, options)
-	// Pass magic string to weave IPAM, which then stores the address under its own string
-	ip, err := i.weave.AllocateIP("_")
-	Log.Debugln("allocateIP returned", ip, err)
-	return ip, nil, err
+	defer func() { Log.Debugln("allocateIP returned", ip, err) }()
+	// If we pass magic string "_" to weave IPAM it stores the address under its own string
+	if poolID == "weavepool" { // old-style
+		ip, err = i.weave.AllocateIP("_")
+		return
+	}
+	parts := strings.Split(poolID, "-")
+	if len(parts) != 3 || parts[0] != "weave" {
+		err = fmt.Errorf("Unrecognized pool ID: %s", poolID)
+		return
+	}
+	var subnet, iprange *net.IPNet
+	if _, subnet, err = net.ParseCIDR(parts[1]); err != nil {
+		return
+	}
+	if _, iprange, err = net.ParseCIDR(parts[2]); err != nil {
+		return
+	}
+	// We are lying slightly to IPAM here: the range is not a subnet
+	if ip, err = i.weave.AllocateIPInSubnet("_", iprange); err != nil {
+		return
+	}
+	ip.Mask = subnet.Mask // fix up the subnet we lied about
+	return
 }
 
 func (i *ipam) ReleaseAddress(poolID string, address net.IP) error {