Merge pull request #5 from digitalocean/rm/add-migrate-set-speed

adding `virsh migrate-setspeed`

internal/constants/constants.go

@@ -26,12 +26,13 @@ const (
 
 // libvirt procedure identifiers
 const (
-	ProcConnectOpen           = 1
-	ProcConnectClose          = 2
-	ProcDomainLookupByName    = 23
-	ProcAuthList              = 66
-	ProcConnectGetLibVersion  = 157
-	ProcConnectListAllDomains = 273
+	ProcConnectOpen              = 1
+	ProcConnectClose             = 2
+	ProcDomainLookupByName       = 23
+	ProcDomainMigrateSetMaxSpeed = 207
+	ProcAuthList                 = 66
+	ProcConnectGetLibVersion     = 157
+	ProcConnectListAllDomains    = 273
 )
 
 // qemu procedure identifiers

libvirt.go

@@ -204,6 +204,44 @@ func (l *Libvirt) Events(dom string) (<-chan DomainEvent, error) {
 	return c, nil
 }
 
+// MigrateSetMaxSpeed set the maximum migration bandwidth (in MiB/s) for a
+// domain which is being migrated to another host. Specifying a negative value
+// results in an essentially unlimited value being provided to the hypervisor.
+func (l *Libvirt) MigrateSetMaxSpeed(dom string, speed int64) error {
+	d, err := l.lookup(dom)
+	if err != nil {
+		return err
+	}
+
+	payload := struct {
+		Padding   [4]byte
+		Domain    Domain
+		Bandwidth int64
+		Flags     uint32
+	}{
+		Padding:   [4]byte{0x0, 0x0, 0x1, 0x0},
+		Domain:    *d,
+		Bandwidth: speed,
+	}
+
+	buf, err := encode(&payload)
+	if err != nil {
+		return err
+	}
+
+	resp, err := l.request(constants.ProcDomainMigrateSetMaxSpeed, constants.ProgramRemote, &buf)
+	if err != nil {
+		return err
+	}
+
+	r := <-resp
+	if r.Status != StatusOK {
+		return decodeError(r.Payload)
+	}
+
+	return nil
+}
+
 // Run executes the given QAPI command against a domain's QEMU instance.
 // For a list of available QAPI commands, see:
 //	http://git.qemu.org/?p=qemu.git;a=blob;f=qapi-schema.json;hb=HEAD

libvirt_test.go

@@ -43,6 +43,15 @@ func TestDisconnect(t *testing.T) {
 	}
 }
 
+func TestMigrateSetMaxSpeed(t *testing.T) {
+	conn := libvirttest.New()
+	l := New(conn)
+
+	if err := l.MigrateSetMaxSpeed("test", 100); err != nil {
+		t.Fatalf("unexpected error setting max speed for migrate: %v", err)
+	}
+}
+
 func TestDomains(t *testing.T) {
 	conn := libvirttest.New()
 	l := New(conn)

libvirttest/libvirt.go

@@ -146,6 +146,16 @@ var testRunReplyFail = []byte{
 	0x6e, 0x64, 0x22, 0x7d, 0x7d, 0x00, 0x00, 0x00,
 }
 
+var testSetSpeedReply = []byte{
+	0x00, 0x00, 0x00, 0x1c, // length
+	0x20, 0x00, 0x80, 0x86, // program
+	0x00, 0x00, 0x00, 0x01, // version
+	0x00, 0x00, 0x00, 0xcf, // procedure
+	0x00, 0x00, 0x00, 0x01, // type
+	0x00, 0x00, 0x00, 0x00, // serial
+	0x00, 0x00, 0x00, 0x00, // status
+}
+
 var testDomainsReply = []byte{
 	0x00, 0x00, 0x00, 0x6c, // length
 	0x20, 0x00, 0x80, 0x86, // program
@@ -250,6 +260,8 @@ func (m *MockLibvirt) handleRemote(procedure uint32, conn net.Conn) {
 		conn.Write(m.reply(testDomainResponse))
 	case constants.ProcConnectListAllDomains:
 		conn.Write(m.reply(testDomainsReply))
+	case constants.ProcDomainMigrateSetMaxSpeed:
+		conn.Write(m.reply(testSetSpeedReply))
 	}
 }