add check script for a systemd unit

check_systemdunit

+#!/bin/bash
+# ================================================================================
+#
+# CHECK A SINGLE SYSTEMD SERVICE
+#
+# (1)
+# shows overview of important services - edit check_systemdservices.cfg to define
+# them
+#
+# (2)
+# resturns
+# - OK      if all systemd servises are running
+# - UNKNOWN if systemctl command is not available
+# - ERROR   if any systemd service is not running
+#
+# -------------------------------------------------------------------------------
+# 2023-09-05  v01.0  <axel.hahn@unibe.ch>
+# ================================================================================
+
+. $( dirname $0 )/inc_pluginfunctions
+
+export self_APPVERSION=1.0
+
+# ----------------------------------------------------------------------
+# FUNCTIONS
+# ----------------------------------------------------------------------
+
+# show help text
+function showHelp(){
+    local _self; _self=$(basename $0)
+cat <<EOF
+$( ph.showImlHelpHeader )
+
+Check a unit using systemctl status.
+
+The status is unknown if the command systemctl is not found.
+The status is critical if the service does not exist or is not running.
+
+SYNTAX:
+  $_self [-h] UNIT
+
+OPTIONS:
+  -h     this help
+  UNIT   Name of a unit - see output of 'systemctl' 
+
+EXAMPLES:
+
+  $_self mysql.service
+         show status of service mysql
+
+EOF
+}
+
+# ----------------------------------------------------------------------
+# MAIN
+# ----------------------------------------------------------------------
+
+ph.hasParamoption "h" "$@"; bOptHelp=$?
+
+if [ $bOptHelp -eq 0 -o $# -eq 0 ]; then
+    showHelp
+    exit 0
+fi
+
+ph.require "systemctl"
+
+_service="${1}"
+_status=$( systemctl --no-pager -l status "${_service}" 2>&1 )
+
+if ! grep "Active: active (running) " <<< "${_status}" >/dev/null; then
+    ph.setStatus critical
+fi
+ph.status "${_status}"
+
+ph.exit
+
+# ----------------------------------------------------------------------