add uptime check

files/nrpe/check_uptime

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+# Nagios Exit Codes
+STATE_OK=0
+STATE_WARNING=1
+STATE_CRITICAL=2
+STATE_UNKNOWN=3
+
+# Default values (in minutes)
+warn=1440
+crit=30
+
+# Retrieve arguments
+while getopts "w:c:" opt; do
+  case $opt in
+    w) warn=$OPTARG ;;
+    c) crit=$OPTARG ;;
+    *) echo "Usage: $0 -w <minutes> -c <minutes>"; exit $STATE_UNKNOWN ;;
+  esac
+done
+
+# Extract uptime (in seconds) via /proc
+uptime_seconds=$(cat /proc/uptime | awk '{print $1}' | cut -d. -f1)
+uptime_min=$((uptime_seconds / 60))
+
+# Performance Data
+PERFDATA="|uptime_min=${uptime_min}min;${warn};${crit};0;"
+
+# Decision logic
+if [ "$uptime_min" -le "$crit" ]; then
+    echo "CRITICAL - Recent reboot detected (${uptime_min} min < threshold ${crit} min)$PERFDATA"
+    exit $STATE_CRITICAL
+elif [ "$uptime_min" -le "$warn" ]; then
+    echo "WARNING - Uptime low (${uptime_min} min < threshold ${warn} min)$PERFDATA"
+    exit $STATE_WARNING
+else
+    echo "OK - System stable (Uptime: ${uptime_min} min)$PERFDATA"
+    exit $STATE_OK
+fi