在小米AX6000中通过米家控制tailscale

由于tailscale占用内存较大，AX6000中的可用内存非常有限，所以需要对AX6000的内存使用进行优化：
1.减小tmpfs内存占用的大小：

#从150M -> 90M，由于tailscale下载安装包是27M作用， 解压后50M左右，所以预留90M够用了
mount -o remount,size=90m /tmp

2.使用cron来执行脚本，而不是通过while循环创建守护进程

crontab -e
*/10 * * * * /etc/tailscale/tailscaleMonitor.sh >/dev/null 2>&1
/etc/init.d/cron restart

3.创建脚本，检查/etc/config/xiaoqiang中uci的led配置状态来控制是否启动tailscale

#!/bin/sh
#crontab -e
#*/10 * * * * /etc/tailscale/tailscaleMonitor.sh >/dev/null 2>&1
#/etc/init.d/cron restart
# Define Tailscale related paths
TAILSCALED_PATH="/tmp/tailscale/tailscale_1.80.3_arm/tailscaled"
TAILSCALE_PATH="/tmp/tailscale/tailscale_1.80.3_arm/tailscale"
LOG_DIR="/etc/tailscale"
LOG_FILE="$LOG_DIR/tailscale.log"
LED_CONFIG="/etc/config/xiaoqiang"
MAX_LOG_SIZE=1048576  # 1MB in bytes
LAST_LED_STATUS_FILE="$LOG_DIR/last_led_status"  # File to store last ledstatus state

# Create log directory
mkdir -p "$LOG_DIR"

# Function: Log messages with log rotation
log() {
    # Check log file size
    if [ -f "$LOG_FILE" ] && [ $(stat -c%s "$LOG_FILE" 2>/dev/null || stat -f%z "$LOG_FILE") -gt $MAX_LOG_SIZE ]; then
        # Rotate log - keep only last 20% of the file
        KEEP_LINES=$(wc -l < "$LOG_FILE" | awk '{print int($1 * 0.2)}')
        if [ $KEEP_LINES -gt 0 ]; then
            tail -n $KEEP_LINES "$LOG_FILE" > "$LOG_FILE.tmp"
            mv "$LOG_FILE.tmp" "$LOG_FILE"
        else
            # If calculation fails, just truncate the file
            echo "" > "$LOG_FILE"
        fi
    fi
    
    echo "$1"
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $1" >> "$LOG_FILE"
}

# Function: Check ledstatus option in xiaoqiang config
check_ledstatus() {
    if [ -f "$LED_CONFIG" ]; then
        LED_STATUS=$(grep -o "option BLUE_LED '[01]'" "$LED_CONFIG" | grep -o "[01]")
        
        # Get last LED_STATUS state
        LAST_LED_STATUS=""
        if [ -f "$LAST_LED_STATUS_FILE" ]; then
            LAST_LED_STATUS=$(cat "$LAST_LED_STATUS_FILE")
        fi
        
        # Log only when LED_STATUS state changes
        if [ "$LED_STATUS" != "$LAST_LED_STATUS" ]; then
            if [ "$LED_STATUS" = "1" ]; then
                log "LED_STATUS state changed to enabled (1), Tailscale should run."
            else
                log "LED_STATUS state changed to disabled (0), Tailscale should not run."
            fi
            # Save new state
            echo "$LED_STATUS" > "$LAST_LED_STATUS_FILE"
        fi
        
        if [ "$LED_STATUS" = "1" ]; then
            return 0
        else
            return 1
        fi
    else
        # Check if we've already logged this error
        if [ -f "$LAST_LED_STATUS_FILE" ] && [ "$(cat "$LAST_LED_STATUS_FILE")" != "error" ]; then
            log "xiaoqiang config file not found at $LED_CONFIG"
            echo "error" > "$LAST_LED_STATUS_FILE"
        fi
        return 1
    fi
}

# Function: Kill Tailscale processes
kill_tailscale() {
    # Find process IDs for tailscale processes
    TAILSCALED_PIDS=$(ps | grep "$TAILSCALED_PATH" | grep -v grep | awk '{print $1}')
    TAILSCALE_PIDS=$(ps | grep "$TAILSCALE_PATH" | grep -v grep | awk '{print $1}')
    
    # Check if any processes were found before trying to kill
    if [ -n "$TAILSCALED_PIDS" ] || [ -n "$TAILSCALE_PIDS" ]; then
        log "Stopping Tailscale processes..."
        
        # Kill tailscale processes
        for PID in $TAILSCALE_PIDS; do
            kill $PID 2>/dev/null
        done
        
        # Kill tailscaled processes
        for PID in $TAILSCALED_PIDS; do
            kill $PID 2>/dev/null
        done
        
        # Give processes a moment to terminate
        sleep 1
        
        # Verify processes were terminated
        REMAINING_TAILSCALED=$(ps | grep "$TAILSCALED_PATH" | grep -v grep)
        REMAINING_TAILSCALE=$(ps | grep "$TAILSCALE_PATH" | grep -v grep)
        
        if [ -z "$REMAINING_TAILSCALED" ] && [ -z "$REMAINING_TAILSCALE" ]; then
            log "Tailscale processes successfully terminated."
        else
            log "Failed to terminate some Tailscale processes, attempting force kill..."
            
            # Try force kill for any remaining processes
            for PID in $(ps | grep "$TAILSCALED_PATH" | grep -v grep | awk '{print $1}'); do
                kill -9 $PID 2>/dev/null
            done
            
            for PID in $(ps | grep "$TAILSCALE_PATH" | grep -v grep | awk '{print $1}'); do
                kill -9 $PID 2>/dev/null
            done
        fi
    fi
}

# Function: Check and start Tailscale
start_tailscale() {
    # Only log when actually starting
    log "Starting Tailscale client..."
    # Run tailscale up without logging its output
    #/tmp/tailscale/tailscale_1.80.3_arm/tailscale up --advertise-routes=192.168.0.0/24 >> "$LOG_FILE" 2>&1 &
    "$TAILSCALE_PATH" up --advertise-routes=192.168.0.0/24 --accept-dns=false >/dev/null 2>&1 &
    if [ $? -eq 0 ]; then
        log "Tailscale started successfully."
    else
        log "Failed to start Tailscale."
    fi
}

# Function: Check and start Tailscaled
start_tailscaled() {
    if [ -z "$(pgrep -f "$TAILSCALED_PATH")" ]; then
        log "Tailscaled is not running, starting..."
        # Run tailscaled without logging its output
        "$TAILSCALED_PATH" >/dev/null 2>&1 &
        if [ $? -eq 0 ]; then
            log "Tailscaled started successfully."
            start_tailscale
        else
            log "Failed to start Tailscaled."
        fi
    fi
}

# Function: Check Tailscale status
check_tailscale_status() {
    # Capture status but don't log it
    STATUS=$("$TAILSCALE_PATH" status 2>/dev/null)
    if echo "$STATUS" | grep "xiaomi-ax6000" >/dev/null; then
        LINE=$(echo "$STATUS" | grep "xiaomi-ax6000")
        FOURTH_FIELD=$(echo "$LINE" | awk '{print $5}')
        if [ "$FOURTH_FIELD" = "offline" ]; then
            log "Device xiaomi-ax6000 is offline, restarting Tailscale..."
            start_tailscaled
        fi
    elif echo "$STATUS" | grep "Tailscale is stopped" >/dev/null; then
        log "Tailscale is stopped, restarting..."
        "$TAILSCALE_PATH" up >/dev/null 2>&1
    else
        log "Device xiaomi-ax6000 not found, starting Tailscale..."
        start_tailscale
    fi
}

# Main logic - Single execution for crontab
#log "Running Tailscale monitor check..."
#log "Running Tailscale monitor check..."

# Check userswitch setting
if check_ledstatus; then
    # ledstatus is 1, monitor and start Tailscale if needed
    if [ -z "$(pgrep -f "$TAILSCALED_PATH")" ]; then
        log "Tailscaled not running, starting services..."
        start_tailscaled
    else
        # Only check status without logging
        check_tailscale_status
    fi
else
    # ledstatus is 0, kill Tailscale processes
    kill_tailscale
fi

#log "Check completed."