add readme

README.md

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+# check_and_reboot
-<!--                    add the following to root's crontab (sudo crontab -e)                    -->
+
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+An automated monitoring and system recovery tool written in Julia that checks network connectivity and website availability, with automatic reboot capabilities when failures are detected.
-@reboot /usr/local/bin/juliar /home/ton/docker-programs/check_yiem_website_reboot/check_yiem_website_reboot.jl >> /var/log/check_reboot.log 2>&1
+
-# *** juliar is root's julia (sudo crontab -e) but I symlinked to juliar because I want to seperate it from user's julia
+## Overview
+
+This project consists of two monitoring scripts:
+
+- **[`check_router_reboot.jl`](check_router_reboot.jl)** - Monitors router connectivity via ICMP ping
+- **[`check_yiem_website_reboot.jl`](check_yiem_website_reboot.jl)** - Monitors website availability via HTTP requests
+
+Both scripts run continuously in the background, performing periodic health checks and automatically rebooting the system if consecutive failures exceed a configured threshold.
+
+## Features
+
+- **Continuous Monitoring**: Runs indefinitely with configurable check intervals
+- **Multi-attempt Verification**: Retries failed checks with backoff before declaring failure
+- **State Persistence**: Maintains state in JSON file across restarts
+- **Cooldown Period**: Prevents rapid repeated reboots after a reboot event
+- **Cross-Platform Support**: Works on Linux, macOS, and Windows with appropriate reboot commands
+- **Broadcast Notifications**: Sends system-wide notifications on events (via `wall`, `logger`, or platform equivalents)
+- **Log Rotation**: Automatically limits log file to last 100 entries to prevent unbounded growth
+- **Dry Run Mode**: Test configuration without triggering actual reboots
+
+## Configuration
+
+### Router Monitor Configuration (`check_router_reboot.jl`)
+
+```julia
+const ROUTER_IP = "192.168.88.1"      # Target router IP address
+const TIMEOUT_SECS = 30                # Request timeout in seconds
+const ATTEMPTS_PER_CHECK = 3           # Number of ping attempts per check
+const BACKOFF_BETWEEN_ATTEMPTS = 60    # Seconds between retry attempts
+const FAILS_TO_REBOOT = 3              # Consecutive failures before reboot
+const COOLDOWN_AFTER_REBOOT_SECS = 600 # Minimum seconds between reboots
+const DRY_RUN = true                   # Set false to enable actual reboots
+const CHECK_INTERVAL_SECS = 60         # Check interval in seconds
+```
+
+### Website Monitor Configuration (`check_yiem_website_reboot.jl`)
+
+```julia
+const URL = "https://www.yiem.cc"      # Target URL to monitor
+const TIMEOUT_SECS = 30                # Request timeout in seconds
+const ATTEMPTS_PER_CHECK = 3           # Number of HTTP attempts per check
+const BACKOFF_BETWEEN_ATTEMPTS = 60    # Seconds between retry attempts
+const FAILS_TO_REBOOT = 3              # Consecutive failures before reboot
+const COOLDOWN_AFTER_REBOOT_SECS = 600 # Minimum seconds between reboots
+const DRY_RUN = false                  # Set false to enable actual reboots
+const CHECK_INTERVAL_SECS = 60         # Check interval in seconds
+```
+
+## Usage
+
+### Running Manually
+
+```bash
+julia check_router_reboot.jl
+julia check_yiem_website_reboot.jl
+```
+
+### Running at System Boot (Crontab)
+
+Add the following to root's crontab (`sudo crontab -e`):
+
+```
+@reboot /usr/local/bin/juliar /path/to/check_router_reboot.jl >> /var/log/check_reboot.log 2>&1
+@reboot /usr/local/bin/juliar /path/to/check_yiem_website_reboot.jl >> /var/log/check_reboot.log 2>&1
+```
+
+**Note**: The scripts use `juliar` which is a symlink to Julia for root (separate from user's Julia installation).
+
+### Required Dependencies
+
+Install the required Julia packages:
+
+```bash
+julia -e 'using Pkg; Pkg.add(["HTTP", "Dates", "JSON"])'
+```
+
+## Files
+
+| File | Description |
+|------|-------------|
+| [`check_router_reboot.jl`](check_router_reboot.jl) | Router ping monitor with auto-reboot |
+| [`check_yiem_website_reboot.jl`](check_yiem_website_reboot.jl) | Website HTTP monitor with auto-reboot |
+| [`check_and_reboot_state.json`](check_and_reboot_state.json) | State persistence file (generated) |
+| [`check_router_reboot_log.txt`](check_router_reboot_log.txt) | Router monitor log file |
+| [`check_website_reboot_log.txt`](check_website_reboot_log.txt) | Website monitor log file |
+
+## State File
+
+The state is stored in [`check_and_reboot_state.json`](check_and_reboot_state.json) with the following structure:
+
+```json
+{
+  "consecutive_fails": 0,
+  "last_reboot_datetime": "2026-03-11T10:00:00"
+}
+```
+
+## Log Output
+
+Logs are written to both the console and the respective log files with timestamps:
+
+```
+[2026-03-11T10:05:09.123] Starting check loop. Checking router 192.168.88.1 every 60 seconds.
+[2026-03-11T10:05:09.456] 192.168.88.1 is reachable; resetting consecutive failure counter.
+[2026-03-11T10:06:09.789] 192.168.88.1 is unreachable (last result: no response). Consecutive fails: 1/3.
+```
+
+## Reboot Commands
+
+The scripts automatically select the appropriate reboot command based on the operating system:
+
+- **Linux**: `sudo systemctl reboot` or `sudo reboot`
+- **macOS**: `sudo shutdown -r now`
+- **Windows**: `shutdown /r /t 0`
+
+## Safety Features
+
+1. **Cooldown Period**: After a reboot, the script waits `COOLDOWN_AFTER_REBOOT_SECS` seconds before performing another check
+2. **Consecutive Failures**: Requires multiple consecutive failures before triggering a reboot
+3. **Dry Run Mode**: Set `DRY_RUN = true` to test without actually rebooting