This is to monitor various objects on a given server and email notifications out when thresholds are exceeded

IT will send out something like this

#!/bin/bash ############################################ # # Author: Steve Ling 5/2/25 # # Purpose: Monitor system metrics including: # - Average Load # - CPU Usage # - Disk Space # - Memory Usage # # Installation: # 1. Copy to /opt/scripts/ # 2. Set permissions: chmod 755 /opt/scripts/loadmon.sh # 3. Set ownership: chown remuser:kiwiplan /opt/scripts/loadmon.sh # 4. Add cron job as root to run every 5 minutes: # */5 * * * * /opt/scripts/loadmon.sh >/dev/null 2>&1 | logger # # Improvements: # - Added error handling for commands and email sending # - Improved logging with timestamps # - Made thresholds configurable via environment variables # - Added hostname to alerts for clarity # - Replaced mutt with mail (more common) # - Optimized command execution # - Added input validation # ############################################ # Exit on any error set -e # Configuration (can be overridden via environment variables) : "${LOAD_THRESHOLD:=10.00}" # Load average threshold : "${DISK_THRESHOLD:=85}" # Disk usage threshold (%) : "${CPU_THRESHOLD:=65}" # CPU usage threshold (%) : "${MEM_THRESHOLD:=85}" # Memory usage threshold (%) : "${RECIPIENTS:=steve.ling@sflservicesllc.com}" # Space-separated email addresses : "${HOSTNAME:=$(hostname -s)}" # Short hostname for alerts : "${LOG_FILE:=/var/log/loadmon.log}" # Log file location # Ensure required commands are available for cmd in awk df top free mail logger; do if ! command -v "$cmd" &>/dev/null; then echo "Error: Required command '$cmd' not found" | logger -t loadmon exit 1 fi done # Function to log messages with timestamp log_message() { local message="$1" echo "$(date '+%Y-%m-%d %H:%M:%S') - $message" | logger -t loadmon echo "$(date '+%Y-%m-%d %H:%M:%S') - $message" >> "$LOG_FILE" } # Function to send email alerts send_alert() { local subject="$1" local body="$2" if echo -e "$body" | mail -s "$subject" $RECIPIENTS 2>/dev/null; then log_message "Alert sent: $subject" else log_message "Error: Failed to send alert: $subject" fi } # Collect system metrics load=$(awk '{print $1}' /proc/loadavg 2>/dev/null || log_message "Error: Failed to read load average") disk_usage=$(df / | awk 'NR==2 {print $5}' | sed 's/%//' 2>/dev/null || log_message "Error: Failed to read disk usage") cpu_usage=$(top -bn1 | grep "Cpu(s)" | awk '{print 100 - $8}' | cut -d. -f1 2>/dev/null || log_message "Error: Failed to read CPU usage") mem_usage=$(free | awk '/Mem:/ {printf "%.0f", $3/$2 * 100}' 2>/dev/null || log_message "Error: Failed to read memory usage") # Validate collected metrics if ! [[ "$load" =~ ^[0-9]+([.][0-9]+)?$ ]]; then log_message "Error: Invalid load value: $load" exit 1 fi if ! [[ "$disk_usage" =~ ^[0-9]+$ ]]; then log_message "Error: Invalid disk usage value: $disk_usage" exit 1 fi if ! [[ "$cpu_usage" =~ ^[0-9]+$ ]]; then log_message "Error: Invalid CPU usage value: $cpu_usage" exit 1 fi if ! [[ "$mem_usage" =~ ^[0-9]+$ ]]; then log_message "Error: Invalid memory usage value: $mem_usage" exit 1 fi # Check thresholds and send alerts if (( $(echo "$load > $LOAD_THRESHOLD" | bc -l) )); then body=$(sar -q 2>/dev/null || echo "Error collecting sar data") send_alert "High load on $HOSTNAME - [ $load ]" "$body" fi if (( disk_usage > DISK_THRESHOLD )); then body=$(df -h / 2>/dev/null || echo "Error collecting df data") send_alert "High disk usage on $HOSTNAME - [ ${disk_usage}% ]" "$body" fi if (( cpu_usage > CPU_THRESHOLD )); then body=$(top -bn1 | head -n 12 2>/dev/null || echo "Error collecting top data") send_alert "High CPU usage on $HOSTNAME - [ ${cpu_usage}% ]" "$body" fi if (( mem_usage > MEM_THRESHOLD )); then body=$(free -h 2>/dev/null || echo "Error collecting free data") send_alert "High memory usage on $HOSTNAME - [ ${mem_usage}% ]" "$body" fi log_message "Monitoring completed: Load=$load, Disk=${disk_usage}%, CPU=${cpu_usage}%, Mem=${mem_usage}%"

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