由于业务需要，服务器上的curl 版本太老了，有漏洞，于是抽点时间升级最新版本，确保服务器间通信安全，然后网上看了些教程，发现各不相同，最后找到一个最简单，最方便的方法，分享给大家。

cURL是一个利用URL语法在命令行下工作的文件传输工具，1997年首次发行。它支持文件上传和下载，所以是综合传输工具，但按传统，习惯称cURL为下载工具。cURL还包含了用于程序开发的libcurl。

对cURL有兴趣的可以参考：

添加一个新的repo

vim /etc/yum.repos.d/city-fan.repo

然后在里面添加如下内容：

Centos6 编辑为如下：

[CityFanforCurl]
name=City Fan Repo
baseurl=http://www.city-fan.org/ftp/contrib/yum-repo/rhel6/x86_64/
enabled=0
gpgcheck=0

Centos7 编辑为如下：

[CityFanforCurl]
name=City Fan Repo
baseurl=http://www.city-fan.org/ftp/contrib/yum-repo/rhel7/x86_64/
enabled=0
gpgcheck=0

更新 cURL

直接使用如下命令进行更新：

yum update curl --enablerepo=CityFanforCurl -y

cURL将会更新到一个最新的稳定版。

重启服务

更新完成后，建议重启一下。就可以正常使用了。

lnmp php-fpm restart

这时候再输入curl --version 输出如下：

curl 7.63.0 (x86_64-redhat-linux-gnu) libcurl/7.63.0 NSS/3.36 zlib/1.2.7 libpsl/0.7.0 (+libicu/50.1.2) libssh2/1.8.0 nghttp2/1.31.1
Release-Date: 2018-12-12
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp 
Features: AsynchDNS IPv6 Largefile GSS-API Kerberos SPNEGO NTLM NTLM_WB SSL libz HTTP2 UnixSockets HTTPS-proxy PSL Metalink 

问题

一台服务器按这个步骤操作下来没有问题，另一台碰到一个问题，报错，大概就是镜像源错误还有CA证书问题：

http://mirror.math.princeton.edu/pub/epel/6/x86_64/repodata/00b164f9525392a7a34d12e3367cc3bc53b9fd4ecd0614cd22ccacdb21eb1b2b-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.mit.edu/epel/6/x86_64/repodata/00b164f9525392a7a34d12e3367cc3bc53b9fd4ecd0614cd22ccacdb21eb1b2b-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirror.metrocast.net/fedora/epel/6/x86_64/repodata/00b164f9525392a7a34d12e3367cc3bc53b9fd4ecd0614cd22ccacdb21eb1b2b-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirror.mrjester.net/fedora/epel/6/x86_64/repodata/00b164f9525392a7a34d12e3367cc3bc53b9fd4ecd0614cd22ccacdb21eb1b2b-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://fedora-epel.mirror.lstn.net/6/x86_64/repodata/00b164f9525392a7a34d12e3367cc3bc53b9fd4ecd0614cd22ccacdb21eb1b2b-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
https://dl.fedoraproject.org/pub/epel/6/x86_64/repodata/00b164f9525392a7a34d12e3367cc3bc53b9fd4ecd0614cd22ccacdb21eb1b2b-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 77 - "Problem with the SSL CA cert (path? access rights?)"

于是执行如下命令，然后从「更新cURL」继续执行。

更新 ca-bundle

首先备份一下：

cp /etc/pki/tls/certs/ca-bundle.crt /etc/pki/tls/certs/ca-bundle.crt.bak

更新并替换：

curl http://curl.haxx.se/ca/cacert.pem -o /etc/pki/tls/certs/ca-bundle.crt

这时候就可以看到yum已经可以正常的查询依赖关系并更新cURL到最新版了，明月更新后是cURL 7.63.0-3.0版，已经是官方的最新版了！