instance helper to execute commands on master

diff --git a/bin/instance b/bin/instance
new file mode 100755 (executable)
index 0000000..9cacded
--- /dev/null
+++ b/bin/instance
@@ -0,0 +1,4 @@
+#!/bin/sh -ex
+
+ssh `gnt-cluster getmaster` \
+gnt-instance $*