Introduce ipam plugin

Makefile

@@ -83,7 +83,7 @@ $(NETCHECK_EXE): prog/netcheck/netcheck.go
 $(SIGPROXY_EXE): prog/sigproxy/main.go
 $(WEAVEWAIT_EXE): prog/weavewait/*.go net/*.go
 $(DOCKERTLSARGS_EXE): prog/docker_tls_args/*.go
-$(DOCKERPLUGIN_EXE): prog/plugin/*.go plugin/net/*.go plugin/skel/*.go api/*.go common/docker/*.go
+$(DOCKERPLUGIN_EXE): prog/plugin/*.go plugin/net/*.go plugin/ipam/*.go plugin/skel/*.go api/*.go common/docker/*.go
 $(TEST_TLS_EXE): test/tls/*.go
 
 $(WEAVEWAIT_EXE) $(SIGPROXY_EXE) $(DOCKERTLSARGS_EXE) $(DOCKERPLUGIN_EXE) $(TEST_TLS_EXE):

ipam/allocate.go

@@ -38,6 +38,11 @@ func (g *allocate) Try(alloc *Allocator) bool {
 	alloc.establishRing()
 
 	if ok, addr := alloc.space.Allocate(g.r); ok {
+		// If caller hasn't supplied a unique ID, file it under the IP address
+		// which lets the caller then release the address using DELETE /ip/address
+		if g.ident == "_" {
+			g.ident = addr.String()
+		}
 		alloc.debugln("Allocated", addr, "for", g.ident, "in", g.r)
 		alloc.addOwned(g.ident, addr)
 		g.resultChan <- allocateResult{addr, nil}

plugin/ipam/driver.go

@@ -0,0 +1,74 @@
+package ipamplugin
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/docker/libnetwork/ipamapi"
+	"github.com/weaveworks/weave/api"
+	. "github.com/weaveworks/weave/common"
+	"github.com/weaveworks/weave/common/docker"
+)
+
+const (
+	WeaveContainer = "weave"
+)
+
+type ipam struct {
+	client *docker.Client
+	weave  *api.Client
+}
+
+func NewIpam(client *docker.Client, version string) (ipamapi.Ipam, error) {
+	return &ipam{client: client}, nil
+}
+
+func (i *ipam) configureWeaveClient() error {
+	if i.weave != nil {
+		return nil
+	}
+	ip, err := i.client.GetContainerIP(WeaveContainer)
+	if err != nil {
+		Log.Warningf("weave ipam not available: %s", err)
+		return fmt.Errorf("weave ipam not available: %s", err)
+	}
+	i.weave = api.NewClient(ip)
+	return nil
+}
+
+func (i *ipam) GetDefaultAddressSpaces() (string, string, error) {
+	Log.Debugln("GetDefaultAddressSpaces")
+	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) {
+	Log.Debugln("RequestPool", addressSpace, pool, subPool, options)
+	_, cidr, _ := net.ParseCIDR("10.32.0.0/12")
+	return "weavepool", cidr, nil, nil
+}
+
+func (i *ipam) ReleasePool(poolID string) error {
+	Log.Debugln("ReleasePool", poolID)
+	return nil
+}
+
+func (i *ipam) RequestAddress(poolID string, address net.IP, options map[string]string) (*net.IPNet, map[string]string, error) {
+	Log.Debugln("RequestAddress", poolID, address, options)
+	// Pass magic string to weave IPAM, which then stores the address under its own string
+	if err := i.configureWeaveClient(); err == nil {
+		ip, err := i.weave.AllocateIP("_")
+		Log.Debugln("allocateIP returned", ip, err)
+		return ip, nil, err
+	} else {
+		return nil, nil, err
+	}
+}
+
+func (i *ipam) ReleaseAddress(poolID string, address net.IP) error {
+	Log.Debugln("ReleaseAddress", poolID, address)
+	if err := i.configureWeaveClient(); err == nil {
+		return i.weave.ReleaseIP(address.String())
+	} else {
+		return err
+	}
+}

plugin/net/driver.go

@@ -27,19 +27,14 @@ type driver struct {
 	endpoints map[string]struct{}
 }
 
-func New(version string, nameserver string) (skel.Driver, error) {
-	client, err := docker.NewClient("unix:///var/run/docker.sock")
-	if err != nil {
-		return nil, errorf("could not connect to docker: %s", err)
-	}
-
+func New(client *docker.Client, version string, nameserver string) (skel.Driver, error) {
 	driver := &driver{
 		nameserver: nameserver,
 		version:    version,
 		endpoints:  make(map[string]struct{}),
 	}
 
-	_, err = NewWatcher(client, driver)
+	_, err := NewWatcher(client, driver)
 	if err != nil {
 		return nil, err
 	}

prog/plugin/main.go

@@ -9,7 +9,9 @@ import (
 	"syscall"
 
 	. "github.com/weaveworks/weave/common"
-	"github.com/weaveworks/weave/plugin/net"
+	"github.com/weaveworks/weave/common/docker"
+	ipamplugin "github.com/weaveworks/weave/plugin/ipam"
+	netplugin "github.com/weaveworks/weave/plugin/net"
 	"github.com/weaveworks/weave/plugin/skel"
 )
 
@@ -39,8 +41,17 @@ func main() {
 
 	Log.Println("Weave plugin", version, "Command line options:", os.Args)
 
-	var d skel.Driver
-	d, err := plugin.New(version, nameserver)
+	dockerClient, err := docker.NewClient("unix:///var/run/docker.sock")
+	if err != nil {
+		Log.Fatalf("unable to connect to docker: %s", err)
+	}
+
+	d, err := netplugin.New(dockerClient, version, nameserver)
+	if err != nil {
+		Log.Fatalf("unable to create driver: %s", err)
+	}
+
+	i, err := ipamplugin.NewIpam(dockerClient, version)
 	if err != nil {
 		Log.Fatalf("unable to create driver: %s", err)
 	}
@@ -62,7 +73,7 @@ func main() {
 
 	endChan := make(chan error, 1)
 	go func() {
-		endChan <- skel.Listen(listener, d, nil)
+		endChan <- skel.Listen(listener, d, i)
 	}()
 
 	select {