first commit , first release

src/zfs-auto-snapshot.sh

@@ -0,0 +1,108 @@
+#!/bin/sh
+
+opt_prefix='zfs-auto-snap'
+
+do_snapshots ()
+{
+	local KEEP=''
+
+	for ii in $TARGETS
+	do
+		zfs snapshot "$ii@$SNAPNAME"
+
+		KEEP="$opt_keep"
+
+		# ASSERT: The old snapshot list is sorted by increasing age.
+		for jj in $SNAPSHOTS_OLD
+		do
+			# Check whether this is an old snapshot of the filesystem.
+			if [ -z "${jj#$ii@$SNAPGLOB}" ]
+			then
+				KEEP=$(( $KEEP - 1 ))
+				if [ "$KEEP" -le '0' ]
+				then
+					zfs destroy -d "$jj"
+
+				fi
+			fi
+		done
+	done
+}
+
+
+# main ()
+# {
+
+while [ "$#" -gt '0' ]
+do
+	case "$1" in 
+		--keep)
+			if   [ ! "$2" -gt '0' ];
+			then
+				exit 1
+			fi
+			opt_keep="$2"
+			shift 2
+			;;
+		--label)
+			opt_label="$2"
+			shift 2
+			;;
+	esac
+done
+
+ZPOOL_STATUS=$(env LC_ALL=C zpool status 2>&1 )
+ZFS_LIST=$(env LC_ALL=C zfs list -t volume,filesystem -H)
+CANDIDATES=$(echo "$ZFS_LIST" | awk -F '\t' '{print $1}')
+SNAPSHOTS_OLD=$(env LC_ALL=C zfs list -H -t snapshot -S creation -o name) 
+
+# Get a list of pools that are being scrubbed.
+ZPOOLS_SCRUBBING=$(echo "$ZPOOL_STATUS" | awk -F ': ' \
+  '$1 ~ /^ *pool$/ { pool = $2 } ; \
+   $1 ~ /^ *scan$/ && $2 ~ /scrub in progress/ { print pool }' \
+  | sort ) 
+
+# Get a list of pools that cannot do a snapshot.
+ZPOOLS_NOTREADY=$(echo "$ZPOOL_STATUS" | awk -F ': ' \
+  '$1 ~ /^ *pool$/ { pool = $2 } ; \
+   $1 ~ /^ *state$/ && $2 !~ /ONLINE|DEGRADED/ { print pool } ' \
+  | sort)
+
+# Initialize the list of datasets that will get a recursive snapshot.
+TARGETS=''
+
+for ii in $CANDIDATES
+do
+	# Exclude datasets in pools that cannot do a snapshot.
+
+	for jj in $ZPOOLS_NOTREADY
+	do
+		if [ "$(echo "$ii" | awk -F/ '{print $1}')" = "$jj" ]
+		then
+			continue 2
+		fi
+	done
+	for jj in $ZPOOLS_SCRUBBING
+	do
+		if [ "$(echo "$ii" | awk -F/ '{print $1}')" = "$jj" ]
+		then
+			continue 2
+		fi
+	done
+
+	TARGETS="$TARGETS $ii"
+done
+
+# ISO style date; fifteen characters: YYYY-MM-DD-HH-MM
+DATE=$(date --utc +%F-%H-%M)
+
+# The snapshot name after the @ symbol.
+SNAPNAME="${opt_prefix}_${opt_label}_$DATE"
+
+# The expression for matching old snapshots.
+SNAPGLOB="${opt_prefix}_${opt_label}_????-??-??-??-??"
+
+do_snapshots "$SNAPNAME" "$SNAPGLOB" "$TARGETS"
+
+exit 0
+# }