From 05f6cae8f841785ba60010dfa8b398e037fb0876 Mon Sep 17 00:00:00 2001
From: Mirek Kratochvil <exa.exa@gmail.com>
Date: Fri, 30 May 2014 17:20:01 +0200
Subject: [PATCH] pulling

---
 zb-cleanup | 13 ++++++++++---
 zb-pull    | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/zb-cleanup b/zb-cleanup
index 825de43..e193fbf 100755
--- a/zb-cleanup
+++ b/zb-cleanup
@@ -6,16 +6,21 @@ if [[ -z "$1" || -z "$2" ]] ; then
 fi
 
 timestamp () {
-	t="`echo \"$1\" |sed -e 's/^.*@zb-//' |tr 'p_' '+ '`"
+	t="`echo \"$1\" |sed -ne 's/^.*@zb-//p' |tr 'p_' '+ '`"
+	[[ -z "$t" ]] && return 1
 	date --date="$t" +%s
+	return $?
 }
 
 density="$2"
 timenow=`date +%s`
 lasttime=0
 
+# list snapshots
 zfs list -t snapshot -r -d 1 -H "$1" |awk '{print $1;}' | while read l ; do
-	echo `timestamp "$l"` "$l"
+	#link unix timestamps
+	unixtime=`timestamp "$l"` || continue
+	echo "$unixtime" "$l"
 done |sort -n | while read l ; do
 	curtime=${l%% *}
 	snapname=${l#* }
@@ -24,7 +29,9 @@ done |sort -n | while read l ; do
 		break
 	fi
 	
-	if [ $(( $density*($curtime-$lasttime)/($timenow-$lasttime) )) -lt 1] ; then
+	#if it's too dense, delete the closer snapshot
+	if [ $(( $density*($curtime-$lasttime)/($timenow-$lasttime) )) -lt 1]
+	then
 		zfs destroy "$snapname"
 	else
 		lasttime="$curtime"
diff --git a/zb-pull b/zb-pull
index 13f4793..af8f9cd 100755
--- a/zb-pull
+++ b/zb-pull
@@ -1,2 +1,59 @@
 #!/bin/sh
 
+if [[ -z "$1" || -z "$2" || -z "$3" ]] ; then
+	echo "usage: $0 <ssh_remote> <remote_zfs_object> <local_zfs_object>" >&2
+	exit 1
+fi
+
+timestamp () {
+	t="`echo \"$1\" |sed -ne 's/^.*@zb-//p' |tr 'p_' '+ '`"
+	[[ -z "$t" ]] && return 1
+	date --date="$t" +%s
+	return $?
+}
+
+
+ssh_remote="$1"
+remote_zfs="$2"
+local_zfs="$3"
+
+# find newest available and newest common snapshot
+newest="N/A"
+newest_common="N/A"
+
+ssh $ssh_remote "zfs list -t snapshot -r -d 1 -H \"${remote_zfs}\" " | while read l ; do
+	#link unix timestamps
+	unixtime=`timestamp "$l"` || continue
+	echo "$unixtime" "$l"
+done | sort -n | while read l ; do
+	curtime=${l%% *}
+	snapname=${l#* }
+
+	newest="$snapname"
+
+	if zfs list -t snapshot -H "${local_zfs}@zb-${snapname}" >/dev/null ; then
+		newest_common="$snapname"
+	fi
+done
+
+# some checks
+
+if [ "$newest" = "N/A" ] ; then
+	echo "$0: no remote snapshots available to pull" >&2
+	exit 2
+fi
+
+if [ "$newest" = "$newest_common" ] ; then
+	echo "$0: nothing new to pull" >&2
+	exit 0
+fi
+
+if [ "$newest_common" = "N/A" ] ; then
+	#do a full send
+	ssh $ssh_remote "zfs send \"${remote_zfs}@zb-${newest}\"" | zfs recv -F "${local_zfs}"
+	exit $?
+else
+	#do incremental send
+	ssh $ssh_remote "zfs send -I \"${remote_zfs}@zb-${newest_common}\" \"${remote_zfs}@zb-${$newest}\"" | zfs recv -F "${local_zfs}"
+	exit $?
+fi