MacOS基础：代理服务器squid的DNS设定方法

约定不等于承诺〃 2022-12-07 16:26 223阅读 0赞

![这里写图片描述][70]这篇文章以squid使用时的错误问题对应为例，介绍一下squid上设定DNS的方法。

### 目录 ###

*  现象
 *  错误原因
 *  设定方法
 *  重启squid服务
 *  结果确认
 *  总结

--------------------

# 现象 #

liumiaocn:~ liumiao$ export https_proxy=http://192.168.31.242:3128
    liumiaocn:~ liumiao$ curl http://www.baidu.com
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
    <html><head>
    <meta type="copyright" content="Copyright (C) 1996-2020 The Squid Software Foundation and contributors">
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <title>ERROR: The requested URL could not be retrieved</title>
    <style type="text/css"></style>
    </head><body id=ERR_DNS_FAIL>
    <div id="titles">
    <h1>ERROR</h1>
    <h2>The requested URL could not be retrieved</h2>
    </div>
    <hr>
    
    <div id="content">
    <p>The following error was encountered while trying to retrieve the URL: <a href="http://www.baidu.com/">http://www.baidu.com/</a></p>
    
    <blockquote id="error">
    <p><b>Unable to determine IP address from host name <q>www.baidu.com</q></b></p>
    </blockquote>
    
    <p>The DNS server returned:</p>
    <blockquote id="data">
    <pre>No DNS records</pre>
    </blockquote>
    
    <p>This means that the cache was not able to resolve the hostname presented in the URL. Check if the address is correct.</p>
    
    <p>Your cache administrator is <a href="mailto:webmaster?subject=CacheErrorInfo%20-%20ERR_DNS_FAIL&body=CacheHost%3A%20localhost%0D%0AErrPage%3A%20ERR_DNS_FAIL%0D%0AErr%3A%20%5Bnone%5D%0D%0ADNS%20ErrMsg%3A%20No%20DNS%20records%0D%0ATimeStamp%3A%20Wed,%2016%20Sep%202020%2013%3A03%3A39%20GMT%0D%0A%0D%0AClientIP%3A%20192.168.31.242%0D%0A%0D%0AHTTP%20Request%3A%0D%0AGET%20%2F%20HTTP%2F1.1%0AUser-Agent%3A%20curl%2F7.64.1%0D%0AAccept%3A%20*%2F*%0D%0AProxy-Connection%3A%20Keep-Alive%0D%0AHost%3A%20www.baidu.com%0D%0A%0D%0A%0D%0A">webmaster</a>.</p>
    <br>
    </div>
    
    <hr>
    <div id="footer">
    <p>Generated Wed, 16 Sep 2020 13:03:39 GMT by localhost (squid/4.13)</p>
    
    </div>
    </body></html>
    liumiaocn:~ liumiao$

--------------------

# 错误原因 #

> 错误信息提示的非常清楚：This means that the cache was not able to resolve the hostname presented in the URL. Check if the address is correct. 然后再看一下会看到如下错误信息：Unable to determine IP address from host name，所以典型的DNS错误，但是需要注意的是却不是操作系统的网络设定处的DNS设定

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdW1pYW9jbg_size_16_color_FFFFFF_t_70_pic_center]

--------------------

# 设定方法 #

在如下squid的配置文件中添加8.8.8.8 和 8.8.4.4作为dns服务器

liumiaocn:~ liumiao$ grep dns /usr/local/etc/squid.conf
    liumiaocn:~ liumiao$ vi /usr/local/etc/squid.conf
    liumiaocn:~ liumiao$ grep dns /usr/local/etc/squid.conf
    dns_nameservers 8.8.8.8 8.8.4.4
    liumiaocn:~ liumiao$

--------------------

# 重启squid服务 #

liumiaocn:~ liumiao$ brew services restart squid
    Stopping `squid`... (might take a while)
    ==> Successfully stopped `squid` (label: homebrew.mxcl.squid)
    ==> Successfully started `squid` (label: homebrew.mxcl.squid)
    liumiaocn:~ liumiao$ 
    liumiaocn:~ liumiao$ brew services list |grep squid
    squid started liumiao /Users/liumiao/Library/LaunchAgents/homebrew.mxcl.squid.plist
    liumiaocn:~ liumiao$

--------------------

# 结果确认 #

liumiaocn:~ liumiao$ export https_proxy=http://192.168.31.242:3128
    liumiaocn:~ liumiao$ curl http://www.baidu.com
    <!DOCTYPE html>
    <html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet type=text/css href=http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css><title>百度一下，你就知道</title></head> <body link=#0000cc> <div id=wrapper> <div id=head> <div class=head_wrapper> <div class=s_form> <div class=s_form_wrapper> <div id=lg> <img hidefocus=true src=//www.baidu.com/img/bd_logo1.png width=270 height=129> </div> <form id=form name=f action=//www.baidu.com/s class=fm> <input type=hidden name=bdorz_come value=1> <input type=hidden name=ie value=utf-8> <input type=hidden name=f value=8> <input type=hidden name=rsv_bp value=1> <input type=hidden name=rsv_idx value=1> <input type=hidden name=tn value=baidu><span class="bg s_ipt_wr"><input id=kw name=wd class=s_ipt value maxlength=255 autocomplete=off autofocus></span><span class="bg s_btn_wr"><input type=submit id=su value=百度一下 class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=http://news.baidu.com name=tj_trnews class=mnav>新闻</a> <a href=http://www.hao123.com name=tj_trhao123 class=mnav>hao123</a> <a href=http://map.baidu.com name=tj_trmap class=mnav>地图</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>视频</a> <a href=http://tieba.baidu.com name=tj_trtieba class=mnav>贴吧</a> <noscript> <a href=http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u=http%3A%2F%2Fwww.baidu.com%2f%3fbdorz_come%3d1 name=tj_login class=lb>登录</a> </noscript> <script>document.write('<a href="http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u='+ encodeURIComponent(window.location.href+ (window.location.search === "" ? "?" : "&")+ "bdorz_come=1")+ '" name="tj_login" class="lb">登录</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">更多产品</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>关于百度</a> <a href=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>©2017 Baidu <a href=http://www.baidu.com/duty/>使用百度前必读</a>  <a href=http://jianyi.baidu.com/ class=cp-feedback>意见反馈</a> 京ICP证030173号  <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html>
    liumiaocn:~ liumiao$

# 总结 #

在squid中添加dns的服务器即可解决squid中无法进行ip和域名更换的问题，实际在这一点上MacOS和Linux并无不同。

[70]: /images/20221123/2d5091d6fbcb4cee8105d5049735a5bd.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpdW1pYW9jbg_size_16_color_FFFFFF_t_70_pic_center]: /images/20221123/1a13d82d0e3f40b09eadc85c9ae51b71.png