introduce snapshot support v1

.gitignore

@@ -14,8 +14,11 @@ examples/interfaces
 examples/ipaddress
 examples/limit
 examples/list
+examples/list_snapshots
 examples/reboot
+examples/restore
 examples/shutdown
+examples/snapshot
 examples/start
 examples/stats
 examples/stop

const.go

@@ -74,4 +74,6 @@ const (
 	errStartFailed                   = "starting the container %q failed"
 	errStopFailed                    = "stopping the container %q failed"
 	errUnfreezeFailed                = "unfreezing the container %q failed"
+	errSnapshotFailed                = "snapshotting the container %q failed"
+	errRestoreFailed                 = "restoring the container %q failed"
 )

container.go

@@ -44,6 +44,14 @@ type Container struct {
 	sync.RWMutex
 }
 
+// Snapshot struct
+type Snapshot struct {
+	Name        string
+	CommentPath string
+	Timestamp   string
+	Path        string
+}
+
 func (lxc *Container) ensureDefinedAndRunning() error {
 	if !lxc.Defined() {
 		return fmt.Errorf(errNotDefined, C.GoString(lxc.container.name))
@@ -98,6 +106,69 @@ func (lxc *Container) MayControl() bool {
 	return bool(C.lxc_container_may_control(lxc.container))
 }
 
+// Snapshot creates a new snapshot
+func (lxc *Container) Snapshot() error {
+	if err := lxc.ensureDefinedButNotRunning(); err != nil {
+		return err
+	}
+
+	lxc.Lock()
+	defer lxc.Unlock()
+
+	if int(C.lxc_container_snapshot(lxc.container)) < 0 {
+		return fmt.Errorf(errSnapshotFailed, C.GoString(lxc.container.name))
+	}
+	return nil
+}
+
+// Restore creates a new snapshot
+func (lxc *Container) Restore(snapshot Snapshot, name string) error {
+	if !lxc.Defined() {
+		return fmt.Errorf(errNotDefined, C.GoString(lxc.container.name))
+	}
+
+	lxc.Lock()
+	defer lxc.Unlock()
+
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+
+	csnapname := C.CString(snapshot.Name)
+	defer C.free(unsafe.Pointer(csnapname))
+
+	if !bool(C.lxc_container_snapshot_restore(lxc.container, csnapname, cname)) {
+		return fmt.Errorf(errRestoreFailed, C.GoString(lxc.container.name))
+	}
+	return nil
+}
+
+// ListSnapshots lists the snapshot of given container
+func (lxc *Container) ListSnapshots() ([]Snapshot, error) {
+	if !lxc.Defined() {
+		return nil, fmt.Errorf(errNotDefined, C.GoString(lxc.container.name))
+	}
+
+	lxc.Lock()
+	defer lxc.Unlock()
+	var snapshots []Snapshot
+
+	size := int(C.lxc_container_snapshot_list_size(lxc.container))
+	if size < 1 {
+		return nil, fmt.Errorf("%s has no snapshots", C.GoString(lxc.container.name))
+	}
+	snapshot := C.lxc_container_snapshot_list(lxc.container)
+	defer freeSnapshots(snapshot, size)
+
+	p := uintptr(unsafe.Pointer(snapshot))
+	for i := 0; i < size; i++ {
+		z := (*C.struct_lxc_snapshot)(unsafe.Pointer(p))
+		s := &Snapshot{Name: C.GoString(z.name), Timestamp: C.GoString(z.timestamp), CommentPath: C.GoString(z.comment_pathname), Path: C.GoString(z.lxcpath)}
+		snapshots = append(snapshots, *s)
+		p += unsafe.Sizeof(*snapshot)
+	}
+	return snapshots, nil
+}
+
 // State returns the container's state
 func (lxc *Container) State() State {
 	lxc.RLock()

examples/list_snapshots.go

@@ -0,0 +1,46 @@
+/*
+ * list_snapshots.go
+ *
+ * Copyright © 2013, S.Çağlar Onur
+ *
+ * Authors:
+ * S.Çağlar Onur <caglar@10ur.org>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+package main
+
+import (
+	"fmt"
+	"github.com/caglar10ur/lxc"
+)
+
+func main() {
+	for _, v := range lxc.Containers() {
+		fmt.Printf("%s\n", v.Name())
+		l, err := v.ListSnapshots()
+		if err != nil {
+			fmt.Printf("ERROR: %s\n", err.Error())
+		}
+
+		for _, s := range l {
+			fmt.Printf("Name: %s\n", s.Name)
+			fmt.Printf("Comment path: %s\n", s.CommentPath)
+			fmt.Printf("Timestamp: %s\n", s.Timestamp)
+			fmt.Printf("LXC path: %s\n", s.Path)
+            fmt.Println()
+		}
+	}
+}

examples/restore.go

@@ -0,0 +1,50 @@
+/*
+ * snapshot.go
+ *
+ * Copyright © 2013, S.Çağlar Onur
+ *
+ * Authors:
+ * S.Çağlar Onur <caglar@10ur.org>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"github.com/caglar10ur/lxc"
+)
+
+var (
+	name string
+)
+
+func init() {
+	flag.StringVar(&name, "name", "rubik", "Name of the container")
+	flag.Parse()
+}
+
+func main() {
+	c := lxc.NewContainer(name)
+	defer lxc.PutContainer(c)
+
+	fmt.Printf("Restoring the container...\n")
+    snapshot := lxc.Snapshot{Name: "snap0"}
+
+	if err := c.Restore(snapshot, "rubik-restore"); err != nil {
+		fmt.Printf("ERROR: %s\n", err.Error())
+	}
+}

examples/snapshot.go

@@ -0,0 +1,48 @@
+/*
+ * snapshot.go
+ *
+ * Copyright © 2013, S.Çağlar Onur
+ *
+ * Authors:
+ * S.Çağlar Onur <caglar@10ur.org>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"github.com/caglar10ur/lxc"
+)
+
+var (
+	name string
+)
+
+func init() {
+	flag.StringVar(&name, "name", "rubik", "Name of the container")
+	flag.Parse()
+}
+
+func main() {
+	c := lxc.NewContainer(name)
+	defer lxc.PutContainer(c)
+
+	fmt.Printf("Snapshoting the container...\n")
+	if err := c.Snapshot(); err != nil {
+		fmt.Printf("ERROR: %s\n", err.Error())
+	}
+}

lxc.c

@@ -243,3 +243,35 @@ int lxc_container_attach_run_wait(struct lxc_container *c, char **argv) {
 bool lxc_container_may_control(struct lxc_container *c) {
     return c->may_control(c);
 }
+
+int lxc_container_snapshot(struct lxc_container *c) {
+    return c->snapshot(c, NULL);
+}
+
+bool lxc_container_snapshot_restore(struct lxc_container *c, char *snapname, char *newname) {
+    return c->snapshot_restore(c, snapname, newname);
+}
+
+int lxc_container_snapshot_list_size(struct lxc_container *c) {
+    int i;
+    struct lxc_snapshot *s;
+
+    int n = c->snapshot_list(c, &s);
+    if (n < 1)
+        return 0;
+
+    for (i = 0; i < n; i++) {
+        s[i].free(&s[i]);
+    }
+    free(s);
+    return n;
+}
+
+struct lxc_snapshot* lxc_container_snapshot_list(struct lxc_container *c) {
+    struct lxc_snapshot *s;
+
+    int n = c->snapshot_list(c, &s);
+    if (n < 1)
+        return NULL;
+    return s;
+}

lxc.h

@@ -56,8 +56,8 @@ extern void lxc_container_want_daemonize(struct lxc_container *);
 extern bool lxc_container_want_close_all_fds(struct lxc_container *);
 extern bool lxc_container_may_control(struct lxc_container *);
 
-//FIXME: Missing API functionality
-//    snapshot
-//    int (*snapshot)(struct lxc_container *c, char *commentfile);
-//    int (*snapshot_list)(struct lxc_container *, struct lxc_snapshot **);
-//    bool (*snapshot_restore)(struct lxc_container *c, char *snapname, char *newname);
+extern int lxc_container_snapshot(struct lxc_container *);
+extern bool lxc_container_snapshot_restore(struct lxc_container *, char *, char *);
+
+extern struct lxc_snapshot* lxc_container_snapshot_list(struct lxc_container *);
+extern int lxc_container_snapshot_list_size(struct lxc_container *);

util.go

@@ -25,6 +25,7 @@ package lxc
 
 /*
 #include <stdlib.h>
+#include <lxc/lxccontainer.h>
 
 static char** makeCharArray(int size) {
     return calloc(sizeof(char*), size);
@@ -40,6 +41,14 @@ static void freeCharArray(char **array, int size) {
         free(array[i]);
     free(array);
 }
+
+static void freeSnapshotArray(struct lxc_snapshot *s, int size) {
+    int i;
+    for (i = 0; i < size; i++) {
+        s[i].free(&s[i]);
+    }
+    free(s);
+}
 */
 import "C"
 
@@ -80,3 +89,7 @@ func convertArgs(cArgs **C.char) []string {
 
 	return s
 }
+
+func freeSnapshots(snapshots *C.struct_lxc_snapshot, size int) {
+	C.freeSnapshotArray(snapshots, C.int(size))
+}