shell脚本检查域名证书是否过期的流程分析

#!/bin/bash
# 检测https证书有效
echo '开始检查 https证书有效期 '

# 先写域名内容到文件中，再读取文件检查证书是否过期了
# 先清空文件
echo '' > /tmp/https_list.txt 

# 这里替换为自己的检查的域名即可
echo 'www.baidu.com' >> /tmp/https_list.txt
echo 'www.bing.com' >> /tmp/https_list.txt
echo 'www.google.com' >> /tmp/https_list.txt

source /etc/profile

# 定义错误的域名
errorDominStr=""

while read line; do
    echo "====================================================================================="
    
    echo "当前检测的域名：" $line
    end_time=$(echo | timeout 1 openssl s_client -servername $line -connect $line:443 2>/dev/null | openssl x509 -noout -enddate 2>/dev/null | awk -F '=' '{print $2}' )
    ([ $? -ne 0 ] || [[ $end_time == '' ]]) && echo '该域名链接不上,跳到下一个域名' && continue
    
    end_times=`date -d "$end_time" +%s `
    current_times=`date -d "$(date -u '+%b %d %T %Y GMT') " +%s `
    
    let left_time=$end_times-$current_times
    days=`expr $left_time / 86400`
    echo "剩余天数: " $days
    
    [ $days -lt 60 ] && echo "https 证书有效期少于60天，存在风险"  && errorDominStr="$errorDominStr \n $line"
    
done < /tmp/https_list.txt

echo -e "准备过期的域名为： \n  $errorDominStr"

if [ "$errorDominStr" = "" ]  
then  
  echo "不包含准备过期的域名"  
else    
  echo "包含准备过期的域名" && exit 10  
fi   
echo "Good bye!"
exit 0