Add nil ipam driver

Signed-off-by: Alessandro Boch <aboch@docker.com>
Signed-off-by: Chun Chen <ramichen@tencent.com>

libnetwork/drivers.go

@@ -9,6 +9,7 @@ import (
 	"github.com/docker/libnetwork/netlabel"
 
 	builtinIpam "github.com/docker/libnetwork/ipams/builtin"
+	nullIpam "github.com/docker/libnetwork/ipams/null"
 	remoteIpam "github.com/docker/libnetwork/ipams/remote"
 )
 
@@ -73,6 +74,7 @@ func initIpams(ic ipamapi.Callback, lDs, gDs interface{}) error {
 	for _, fn := range [](func(ipamapi.Callback, interface{}, interface{}) error){
 		builtinIpam.Init,
 		remoteIpam.Init,
+		nullIpam.Init,
 	} {
 		if err := fn(ic, lDs, gDs); err != nil {
 			return err

libnetwork/ipamapi/contract.go

@@ -15,6 +15,8 @@ import (
 const (
 	// DefaultIPAM is the name of the built-in default ipam driver
 	DefaultIPAM = "default"
+	// NullIPAM is the name of the built-in null ipam driver
+	NullIPAM = "null"
 	// PluginEndpointType represents the Endpoint Type used by Plugin system
 	PluginEndpointType = "IpamDriver"
 	// RequestAddressType represents the Address Type used when requesting an address

libnetwork/ipams/null/null.go

@@ -0,0 +1,71 @@
+// Package null implements the null ipam driver. Null ipam driver satisfies ipamapi contract,
+// but does not effectively reserve/allocate any address pool or address
+package null
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/docker/libnetwork/discoverapi"
+	"github.com/docker/libnetwork/ipamapi"
+	"github.com/docker/libnetwork/types"
+)
+
+var (
+	defaultAS      = "null"
+	defaultPool, _ = types.ParseCIDR("0.0.0.0/0")
+	defaultPoolID  = fmt.Sprintf("%s/%s", defaultAS, defaultPool.String())
+)
+
+type allocator struct{}
+
+func (a *allocator) GetDefaultAddressSpaces() (string, string, error) {
+	return defaultAS, defaultAS, nil
+}
+
+func (a *allocator) RequestPool(addressSpace, pool, subPool string, options map[string]string, v6 bool) (string, *net.IPNet, map[string]string, error) {
+	if addressSpace != defaultAS {
+		return "", nil, nil, types.BadRequestErrorf("unknown address space: %s", addressSpace)
+	}
+	if pool != "" {
+		return "", nil, nil, types.BadRequestErrorf("null ipam driver does not handle specific address pool requests")
+	}
+	if subPool != "" {
+		return "", nil, nil, types.BadRequestErrorf("null ipam driver does not handle specific address subpool requests")
+	}
+	if v6 {
+		return "", nil, nil, types.BadRequestErrorf("null ipam driver does not handle IPv6 address pool pool requests")
+	}
+	return defaultPoolID, defaultPool, nil, nil
+}
+
+func (a *allocator) ReleasePool(poolID string) error {
+	return nil
+}
+
+func (a *allocator) RequestAddress(poolID string, ip net.IP, opts map[string]string) (*net.IPNet, map[string]string, error) {
+	if poolID != defaultPoolID {
+		return nil, nil, types.BadRequestErrorf("unknown pool id: %s", poolID)
+	}
+	return nil, nil, nil
+}
+
+func (a *allocator) ReleaseAddress(poolID string, ip net.IP) error {
+	if poolID != defaultPoolID {
+		return types.BadRequestErrorf("unknown pool id: %s", poolID)
+	}
+	return nil
+}
+
+func (a *allocator) DiscoverNew(dType discoverapi.DiscoveryType, data interface{}) error {
+	return nil
+}
+
+func (a *allocator) DiscoverDelete(dType discoverapi.DiscoveryType, data interface{}) error {
+	return nil
+}
+
+// Init registers a remote ipam when its plugin is activated
+func Init(ic ipamapi.Callback, l, g interface{}) error {
+	return ic.RegisterIpamDriver(ipamapi.NullIPAM, &allocator{})
+}

libnetwork/ipams/null/null_test.go

@@ -0,0 +1,61 @@
+package null
+
+import (
+	"testing"
+
+	_ "github.com/docker/libnetwork/testutils"
+	"github.com/docker/libnetwork/types"
+)
+
+func TestPoolRequest(t *testing.T) {
+	a := allocator{}
+
+	pid, pool, _, err := a.RequestPool(defaultAS, "", "", nil, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !types.CompareIPNet(defaultPool, pool) {
+		t.Fatalf("Unexpected pool returned. Expected %v. Got: %v", defaultPool, pool)
+	}
+	if pid != defaultPoolID {
+		t.Fatalf("Unexpected pool id returned. Expected: %s. Got: %s", defaultPoolID, pid)
+	}
+
+	_, _, _, err = a.RequestPool("default", "", "", nil, false)
+	if err == nil {
+		t.Fatalf("Unexpected success")
+	}
+
+	_, _, _, err = a.RequestPool(defaultAS, "192.168.0.0/16", "", nil, false)
+	if err == nil {
+		t.Fatalf("Unexpected success")
+	}
+
+	_, _, _, err = a.RequestPool(defaultAS, "", "192.168.0.0/24", nil, false)
+	if err == nil {
+		t.Fatalf("Unexpected success")
+	}
+
+	_, _, _, err = a.RequestPool(defaultAS, "", "", nil, true)
+	if err == nil {
+		t.Fatalf("Unexpected success")
+	}
+}
+
+func TestOtherRequests(t *testing.T) {
+	a := allocator{}
+
+	ip, _, err := a.RequestAddress(defaultPoolID, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if ip != nil {
+		t.Fatalf("Unexpected address returned: %v", ip)
+	}
+
+	_, _, err = a.RequestAddress("anypid", nil, nil)
+	if err == nil {
+		t.Fatalf("Unexpected success")
+	}
+
+}