Bash • Script for checking inactive Services

Code:

#!/bin/bash# Comprehensive Service Monitor and Recovery Script for Debian-based systems# This script sets up a systemd service to monitor and automatically restart critical services if they become inactive.# Services monitored: MariaDB, Apache2, Nginx, PHP7.4, Redis, Memcached# Ensure the script is run as rootif [ "$EUID" -ne 0 ]; then    echo "Please run as root"    exit 1fi# Define the path for the monitor scriptMONITOR_SCRIPT="/usr/local/bin/service_monitor.sh"# Define the path for the systemd service fileSERVICE_FILE="/etc/systemd/system/service-monitor.service"# Log file pathLOG_FILE="/var/log/service_monitor.log"# Create the monitor scriptcat << EOF > "$MONITOR_SCRIPT"#!/bin/bash# Log file pathLOG_FILE="/var/log/service_monitor.log"# Array of services to monitorSERVICES=("mariadb" "apache2" "nginx" "php7.4-fpm" "redis-server" "memcached")# Function to log messageslog_message() {    echo "\$(date '+%Y-%m-%d %H:%M:%S') - \$1" >> "\$LOG_FILE"}# Function to check and restart a servicecheck_and_restart_service() {    local service=\$1    if ! systemctl is-active --quiet "\$service"; then        log_message "Service \$service is inactive. Waiting 2 minutes before attempting restart."        sleep 120        if ! systemctl is-active --quiet "\$service"; then            log_message "Attempting to restart \$service"            if systemctl restart "\$service"; then                log_message "Service \$service restarted successfully"            else                log_message "Failed to restart \$service. Manual intervention may be required."            fi        else            log_message "Service \$service is now active. No restart needed."        fi    fi}# Main loopwhile true; do    for service in "\${SERVICES[@]}"; do        # Use a subshell to handle each service check concurrently        (            check_and_restart_service "\$service"        ) &    done    # Wait for all background processes to finish    wait    # Sleep for 2 minutes before the next check    sleep 120doneEOF# Make the monitor script executablechmod +x "$MONITOR_SCRIPT"# Create the systemd service filecat << EOF > "$SERVICE_FILE"[Unit]Description=Service Monitor and RecoveryAfter=network.target[Service]ExecStart=$MONITOR_SCRIPTRestart=alwaysUser=root[Install]WantedBy=multi-user.targetEOF# Reload systemd, enable and start the servicesystemctl daemon-reloadsystemctl enable service-monitor.servicesystemctl start service-monitor.serviceecho "Service monitor has been set up and started."echo "You can check its status with: systemctl status service-monitor"echo "Logs are available at: $LOG_FILE"