Add network connection test

Script now waits for network connectivity before attempting backup.  Useful when ran on a laptop, systemd may trigger before network is back up.

backup.sh

@@ -1,6 +1,16 @@
 #!/bin/bash
 exec &>>/var/log/restic.log
 source /etc/restic/restic_env.sh
+
+# Check network connectivity
+if [[ -x /usr/bin/nmcli ]]; then
+  while [[ $(nmcli n connectivity check) != "full" ]]; do
+    echo "No network connection... "
+    sleep 10
+    echo "Checking network"
+  done
+fi
+
 cd ${BACKUP_ROOT}
 date +"%h %e %T $HOSTNAME restic $$[$BASHPID]: Starting backup"
 restic backup --exclude-file /etc/restic/excludes.txt .