网页正常性监控脚本

#!/bin/bash

# Script name: httpmonitor.sh
# Author: wanghongwei
# Date: 2023-11-30
# Version: 1.0
# Description: A script to monitor http request and send email alerts
# Description: 使用 cURL 请求网页，如果连续三次失败，则发送告警信息
# Usage: ./httpmonitor.sh

# Define lockfile and add exclusive lock
LOCKFILE=/var/run/httpmonitor.lock
exec 200>$LOCKFILE
flock -n 200
if [ $? != 0 ]; then
	echo "Fatal: The script is already running!" && exit 1
fi

trap "exec 200>&-; rm -f $LOCKFILE; exit" SIGINT SIGTERM

# Define the logfile
LOGFILE=/var/log/httpmonitor.log

# Define the email subject and recipient
SUBJECT="HTTP Requests Failure"
RECIPIENT="[email protected]"

# Define the fail count and url
FAIL_COUNT=0
URL=https://www.example.com

while true; do
	# Request the URL and obtain the HTTP return code
	DATE=$(date +"%Y-%m-%d %H:%M:%S")
	HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" "$URL")
	echo -e "${DATE}\t${URL}\t${HTTP_CODE}" >>$LOGFILE

	# Count the number of failures
	if [ $HTTP_CODE -eq 200 ]; then
		FAIL_COUNT=0
	else
		FAIL_COUNT=$((FAIL_COUNT + 1))
	fi

	# Determine if the number of failures has reached 3
	if [ $FAIL_COUNT -eq 3 ]; then
		echo -e "网站 $URL 请求异常,请检查网络连接." | mailx -s "$SUBJECT" "$RECIPIENT"
		sleep 30
		FAIL_COUNT=0
	fi

	# Sleep for 2 seconds before checking again
	sleep 2
done