#!/bin/bash
# Usage: "Linux - Automatic Services Monitor.sh"
# 
# Description:
#   This script is used from inside of Tactical RMM instances to monitor all automatic starting services. 
#   This script should be deployed as a check script.
#
# Options:
#
# Author: D. de Kooker (info@dcomputers.nl)
# Sources: n/a Created with the help of openai
# Changelog :
#   16-09-2023 - Initial script 

# Array of services to exclude from monitoring
# // EXCLUDE=("service_to_exclude1" "service_to_exclude2")
EXCLUDE=("")

# Function to check the status of a service and display its last error message
check_service_status() {
    service_name="$1"
    systemctl is-active --quiet "$service_name"
    if [ $? -eq 0 ]; then
        return 0  # Service is running
    else
        return 1  # Service is not running
    fi
}

# Function to get and display the last error message from the service's status log
display_last_error_message() {
    service_name="$1"
    last_error_message=$(journalctl -n 1 -u "$service_name" --no-pager --quiet)
    if [ -n "$last_error_message" ]; then
        echo "Last error message for $service_name:"
        echo "$last_error_message"
    fi
}

# Array to store the names of stopped services
STOPPED_SERVICES=()

# Main loop to monitor all services except excluded ones
# echo "Monitoring all services set to start automatically..."

# Get the list of all enabled services
enabled_services=$(systemctl list-units --type=service --state=active --no-legend | awk '{print $1}')

for service in $enabled_services; do
    # Check if the service is in the exclusion list
    if [[ ! " ${EXCLUDE[@]} " =~ " $service " ]]; then
        if ! check_service_status "$service"; then
                STOPPED_SERVICES+=("$service")
        fi
    fi
done

if [ ${#STOPPED_SERVICES[@]} -eq 0 ]; then
    echo "All services are running."
    exit 0
else
    echo "Services in error/stopped state:"
    for stopped_service in "${STOPPED_SERVICES[@]}"; do
        echo "$stopped_service"
        display_last_error_message "$stopped_service"
        echo ""
    done
    exit 1
fi