From ed68bffea5b9eb384e23284015d1c1145dcaacab Mon Sep 17 00:00:00 2001
From: Christian Schwarz <me@cschwarz.com>
Date: Sun, 12 Nov 2017 23:05:18 +0100
Subject: [PATCH] bookmark every snapshot

replication logic already supports bookmarks \o/

refs #34
---
 cmd/autosnap.go | 13 ++++++++++---
 cmd/prune.go    |  1 +
 zfs/zfs.go      | 35 ++++++++++++++++++++++++++++++++++-
 3 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/cmd/autosnap.go b/cmd/autosnap.go
index 8018089..8fce1dd 100644
--- a/cmd/autosnap.go
+++ b/cmd/autosnap.go
@@ -129,14 +129,21 @@ func (a *IntervalAutosnap) doSnapshots(didSnaps chan struct{}) {
 		suffix := time.Now().In(time.UTC).Format("20060102_150405_000")
 		snapname := fmt.Sprintf("%s%s", a.Prefix, suffix)
 
-		a.log.WithField(logFSField, d.ToString()).
-			WithField("snapname", snapname).
-			Info("create snapshot")
+		l := a.log.WithField(logFSField, d.ToString()).
+			WithField("snapname", snapname)
 
+		l.Info("create snapshot")
 		err := zfs.ZFSSnapshot(d, snapname, false)
 		if err != nil {
 			a.log.WithError(err).Error("cannot create snapshot")
 		}
+
+		l.Info("create corresponding bookmark")
+		err = zfs.ZFSBookmark(d, snapname, snapname)
+		if err != nil {
+			a.log.WithError(err).Error("cannot create bookmark")
+		}
+
 	}
 
 	select {
diff --git a/cmd/prune.go b/cmd/prune.go
index a59cd00..a43aac5 100644
--- a/cmd/prune.go
+++ b/cmd/prune.go
@@ -46,6 +46,7 @@ func (p *Pruner) Run(ctx context.Context) (r []PruneResult, err error) {
 
 		log := log.WithField(logFSField, fs.ToString())
 
+		// only prune snapshots, bookmarks are kept forever
 		snapshotFilter := NewTypedPrefixFilter(p.SnapshotPrefix, zfs.Snapshot)
 		fsversions, err := zfs.ZFSListFilesystemVersions(fs, snapshotFilter)
 		if err != nil {
diff --git a/zfs/zfs.go b/zfs/zfs.go
index 2b8005a..755af10 100644
--- a/zfs/zfs.go
+++ b/zfs/zfs.go
@@ -286,9 +286,17 @@ func ZFSDestroy(dataset string) (err error) {
 
 }
 
+func zfsBuildSnapName(fs *DatasetPath, name string) string { // TODO defensive
+	return fmt.Sprintf("%s@%s", fs.ToString(), name)
+}
+
+func zfsBuildBookmarkName(fs *DatasetPath, name string) string { // TODO defensive
+	return fmt.Sprintf("%s#%s", fs.ToString(), name)
+}
+
 func ZFSSnapshot(fs *DatasetPath, name string, recursive bool) (err error) {
 
-	snapname := fmt.Sprintf("%s@%s", fs.ToString(), name)
+	snapname := zfsBuildSnapName(fs, name)
 	cmd := exec.Command(ZFS_BINARY, "snapshot", snapname)
 
 	stderr := bytes.NewBuffer(make([]byte, 0, 1024))
@@ -308,3 +316,28 @@ func ZFSSnapshot(fs *DatasetPath, name string, recursive bool) (err error) {
 	return
 
 }
+
+func ZFSBookmark(fs *DatasetPath, snapshot, bookmark string) (err error) {
+
+	snapname := zfsBuildSnapName(fs, snapshot)
+	bookmarkname := zfsBuildBookmarkName(fs, bookmark)
+
+	cmd := exec.Command(ZFS_BINARY, "bookmark", snapname, bookmarkname)
+
+	stderr := bytes.NewBuffer(make([]byte, 0, 1024))
+	cmd.Stderr = stderr
+
+	if err = cmd.Start(); err != nil {
+		return err
+	}
+
+	if err = cmd.Wait(); err != nil {
+		err = ZFSError{
+			Stderr:  stderr.Bytes(),
+			WaitErr: err,
+		}
+	}
+
+	return
+
+}