Merge pull request lxc#25 from caglar10ur/CloneOptions

introduce CloneOptions

container.go

@@ -39,6 +39,13 @@ type Snapshot struct {
 	Path        string
 }
 
+const (
+	isDefined = 1 << iota
+	isNotDefined
+	isRunning
+	isNotRunning
+)
+
 func (c *Container) makeSure(flags int) error {
 	if flags&isDefined != 0 && !c.Defined() {
 		return ErrNotDefined
@@ -296,11 +303,7 @@ func (c *Container) Unfreeze() error {
 
 // Create creates the container using given TemplateOptions
 func (c *Container) Create(options TemplateOptions) error {
-	// FIXME: Support bdevtype and bdev_specs
-	// bdevtypes:
-	// "btrfs", "zfs", "lvm", "dir"
-	//
-	// best tries to find the best backing store type
+	// FIXME: Support bdev_specs
 	//
 	// bdev_specs:
 	// zfs requires zfsroot
@@ -428,27 +431,25 @@ func (c *Container) Execute(args ...string) ([]byte, error) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	/*
-	 * FIXME: Go runtime and src/lxc/start.c signal_handler are not playing nice together so use lxc-execute for now
-	 * go-nuts thread: https://groups.google.com/forum/#!msg/golang-nuts/h9GbvfYv83w/5Ly_jvOr86wJ
-	 */
+	// FIXME: Go runtime and src/lxc/start.c signal_handler are not playing nice together so use lxc-execute for now
+	// go-nuts thread: https://groups.google.com/forum/#!msg/golang-nuts/h9GbvfYv83w/5Ly_jvOr86wJ
 	output, err := exec.Command(cargs[0], cargs[1:]...).CombinedOutput()
 	if err != nil {
 		return nil, ErrExecuteFailed
 	}
 
 	return output, nil
 	/*
-		   cargs := makeNullTerminatedArgs(args)
-		   if cargs == nil {
-			   return ErrAllocationFailed
-		   }
-		   defer freeNullTerminatedArgs(cargs, len(args))
-
-		   if !bool(C.go_lxc_start(c.container, 1, cargs)) {
-			   return ErrExecuteFailed
-		   }
-		   return nil
+		cargs := makeNullTerminatedArgs(args)
+		if cargs == nil {
+			return ErrAllocationFailed
+		}
+		defer freeNullTerminatedArgs(cargs, len(args))
+
+		if !bool(C.go_lxc_start(c.container, 1, cargs)) {
+			return ErrExecuteFailed
+		}
+		return nil
 	*/
 }
 
@@ -511,15 +512,9 @@ func (c *Container) Destroy() error {
 	return nil
 }
 
-// CloneUsing clones the container using given arguments with specified backend.
-//
-// Additional flags to change the cloning behaviour:
-// CloneKeepName, CloneKeepMACAddr, CloneSnapshot and CloneMaybeSnapshot
-func (c *Container) CloneUsing(name string, backend BackendStore, flags CloneFlags) error {
-	// FIXME: support lxcpath, bdevtype, bdevdata, newsize and hookargs
-	//
-	// bdevtypes:
-	// "btrfs", "zfs", "lvm", "dir" "overlayfs"
+// Clone clones the container using given arguments with specified backend.
+func (c *Container) Clone(name string, options CloneOptions) error {
+	// FIXME: bdevdata, newsize and hookargs
 	//
 	// bdevdata:
 	// zfs requires zfsroot
@@ -537,23 +532,43 @@ func (c *Container) CloneUsing(name string, backend BackendStore, flags CloneFla
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
+	// use Directory backend if not set
+	if options.Backend == 0 {
+		options.Backend = Directory
+	}
+
+	var flags int
+	if options.KeepName {
+		flags |= C.LXC_CLONE_KEEPNAME
+	}
+	if options.KeepMAC {
+		flags |= C.LXC_CLONE_KEEPMACADDR
+	}
+	if options.Snapshot {
+		flags |= C.LXC_CLONE_SNAPSHOT
+	}
+
 	cname := C.CString(name)
 	defer C.free(unsafe.Pointer(cname))
 
-	cbackend := C.CString(backend.String())
+	cbackend := C.CString(options.Backend.String())
 	defer C.free(unsafe.Pointer(cbackend))
 
-	if !bool(C.go_lxc_clone(c.container, cname, C.int(flags), cbackend)) {
-		return ErrCloneFailed
+	if options.ConfigPath != "" {
+		clxcpath := C.CString(options.ConfigPath)
+		defer C.free(unsafe.Pointer(clxcpath))
+
+		if !bool(C.go_lxc_clone(c.container, cname, clxcpath, C.int(flags), cbackend)) {
+			return ErrCloneFailed
+		}
+	} else {
+		if !bool(C.go_lxc_clone(c.container, cname, nil, C.int(flags), cbackend)) {
+			return ErrCloneFailed
+		}
 	}
 	return nil
 }
 
-// Clone clones the container using the Directory backendstore.
-func (c *Container) Clone(name string) error {
-	return c.CloneUsing(name, Directory, 0)
-}
-
 // Rename renames the container.
 func (c *Container) Rename(name string) error {
 	if err := c.makeSure(isDefined | isNotRunning); err != nil {

error.go

@@ -57,6 +57,7 @@ var (
 	ErrStartFailed                   = NewError("starting the container failed")
 	ErrStopFailed                    = NewError("stopping the container failed")
 	ErrUnfreezeFailed                = NewError("unfreezing the container failed")
+	ErrUnknownBackendStore           = NewError("unknown backend type")
 )
 
 // Error represents a basic error that implies the error interface.

examples/clone.go

@@ -16,11 +16,13 @@ import (
 var (
 	lxcpath string
 	name    string
+	backend lxc.BackendStore
 )
 
 func init() {
 	flag.StringVar(&lxcpath, "lxcpath", lxc.DefaultConfigPath(), "Use specified container path")
 	flag.StringVar(&name, "name", "rubik", "Name of the original container")
+	flag.Var(&backend, "backend", "Backend type to use, possible values are [dir, zfs, btrfs, lvm, aufs, overlayfs, loopback, best]")
 	flag.Parse()
 }
 
@@ -30,28 +32,15 @@ func main() {
 		log.Fatalf("ERROR: %s\n", err.Error())
 	}
 
-	directoryClone := name + "Directory"
-	overlayClone := name + "Overlayfs"
-	btrfsClone := name + "Btrfs"
-	aufsClone := name + "Aufs"
-
-	log.Printf("Cloning the container using Directory backend...\n")
-	if err := c.Clone(directoryClone); err != nil {
-		log.Fatalf("ERROR: %s\n", err.Error())
-	}
-
-	log.Printf("Cloning the container using Overlayfs backend...\n")
-	if err := c.CloneUsing(overlayClone, lxc.Overlayfs, lxc.CloneSnapshot); err != nil {
-		log.Fatalf("ERROR: %s\n", err.Error())
+	if backend == 0 {
+		log.Fatalf("ERROR: %s\n", lxc.ErrUnknownBackendStore)
 	}
 
-	log.Printf("Cloning the container using Aufs backend...\n")
-	if err := c.CloneUsing(aufsClone, lxc.Aufs, lxc.CloneSnapshot); err != nil {
-		log.Fatalf("ERROR: %s\n", err.Error())
-	}
-
-	log.Printf("Cloning the container using Btrfs backend...\n")
-	if err := c.CloneUsing(btrfsClone, lxc.Btrfs, 0); err != nil {
+	log.Printf("Cloning the container using %s backend...\n", backend)
+	err = c.Clone(name+"_"+backend.String(), lxc.CloneOptions{
+		Backend: backend,
+	})
+	if err != nil {
 		log.Fatalf("ERROR: %s\n", err.Error())
 	}
 }

lxc.c

@@ -148,8 +148,8 @@ bool go_lxc_save_config(struct lxc_container *c, const char *alt_file) {
 	return c->save_config(c, alt_file);
 }
 
-bool go_lxc_clone(struct lxc_container *c, const char *newname, int flags, const char *bdevtype) {
-	return c->clone(c, newname, NULL, flags, bdevtype, NULL, 0, NULL) != NULL;
+bool go_lxc_clone(struct lxc_container *c, const char *newname, const char *lxcpath, int flags, const char *bdevtype) {
+	return c->clone(c, newname, lxcpath, flags, bdevtype, NULL, 0, NULL) != NULL;
 }
 
 int go_lxc_console_getfd(struct lxc_container *c, int ttynum) {

lxc.h

@@ -5,7 +5,7 @@
 extern bool go_lxc_add_device_node(struct lxc_container *c, const char *src_path, const char *dest_path);
 extern void go_lxc_clear_config(struct lxc_container *c);
 extern bool go_lxc_clear_config_item(struct lxc_container *c, const char *key);
-extern bool go_lxc_clone(struct lxc_container *c, const char *newname, int flags, const char *bdevtype);
+extern bool go_lxc_clone(struct lxc_container *c, const char *newname, const char *lxcpath, int flags, const char *bdevtype);
 extern bool go_lxc_console(struct lxc_container *c, int ttynum, int stdinfd, int stdoutfd, int stderrfd, int escape);
 extern bool go_lxc_create(struct lxc_container *c, const char *t, const char *bdevtype, int flags, char * const argv[]);
 extern bool go_lxc_defined(struct lxc_container *c);

lxc_test.go

@@ -158,7 +158,7 @@ func TestClone(t *testing.T) {
 		t.Errorf(err.Error())
 	}
 
-	if err := c.Clone(ContainerCloneName); err != nil {
+	if err = c.Clone(ContainerCloneName, DefaultCloneOptions); err != nil {
 		t.Errorf(err.Error())
 	}
 }
@@ -173,7 +173,13 @@ func TestCloneUsingOverlayfs(t *testing.T) {
 		t.Errorf(err.Error())
 	}
 
-	if err := c.CloneUsing(ContainerCloneOverlayName, Overlayfs, CloneSnapshot|CloneKeepName|CloneKeepMACAddr); err != nil {
+	err = c.Clone(ContainerCloneOverlayName, CloneOptions{
+		Backend:  Overlayfs,
+		KeepName: true,
+		KeepMAC:  true,
+		Snapshot: true,
+	})
+	if err != nil {
 		t.Errorf(err.Error())
 	}
 }
@@ -192,7 +198,13 @@ func TestCloneUsingAufs(t *testing.T) {
 		t.Errorf(err.Error())
 	}
 
-	if err := c.CloneUsing(ContainerCloneAufsName, Aufs, CloneSnapshot|CloneKeepName|CloneKeepMACAddr); err != nil {
+	err = c.Clone(ContainerCloneAufsName, CloneOptions{
+		Backend:  Aufs,
+		KeepName: true,
+		KeepMAC:  true,
+		Snapshot: true,
+	})
+	if err != nil {
 		t.Errorf(err.Error())
 	}
 }
@@ -1260,7 +1272,7 @@ func TestBackendStore(t *testing.T) {
 		store BackendStore
 	}
 
-	if X.store.String() != "<INVALID>" {
+	if X.store.String() != "" {
 		t.Error("zero value of BackendStore should be invalid")
 	}
 }
@@ -1270,7 +1282,7 @@ func TestState(t *testing.T) {
 		state State
 	}
 
-	if X.state.String() != "<INVALID>" {
+	if X.state.String() != "" {
 		t.Error("zero value of State should be invalid")
 	}
 }

options.go

@@ -64,6 +64,7 @@ var DefaultAttachOptions = AttachOptions{
 
 // TemplateOptions type is used for defining various template options.
 type TemplateOptions struct {
+
 	// Template specifies the name of the template.
 	Template string
 
@@ -149,3 +150,27 @@ var DefaultConsoleOptions = ConsoleOptions{
 	StderrFd:        os.Stderr.Fd(),
 	EscapeCharacter: 'a',
 }
+
+// CloneOptions type is used for defining various clone options.
+type CloneOptions struct {
+
+	// Backend specifies the type of the backend.
+	Backend BackendStore
+
+	// lxcpath in which to create the new container. If not set the original container's lxcpath will be used.
+	ConfigPath string
+
+	// Do not change the hostname of the container (in the root filesystem).
+	KeepName bool
+
+	// Use the same MAC address as the original container, rather than generating a new random one.
+	KeepMAC bool
+
+	// Create a snapshot rather than copy.
+	Snapshot bool
+}
+
+// DefaultCloneOptions is a convenient set of options to be used.
+var DefaultCloneOptions = CloneOptions{
+	Backend: Directory,
+}