Add a first test for the firewall

tests/01-ssh_test_via_NAS.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+set -o errexit
+set -o pipefail
+set -o nounset
+
+NAS_USER="fwtest"
+NAS_HOST="10.24.20.250"
+
+FW_USER="fwtest"
+FW_HOST="10.24.0.1"
+
+TEST_CMD="/bin/true" # actually, a good choice, because we'll receive non-0 status code anyway if anything fails
+
+/usr/bin/ssh -l "${NAS_USER}" "${NAS_HOST}" \
+    /usr/bin/ssh -l "${FW_USER}" "${FW_HOST}" ${TEST_CMD}
+
+exit $?
+