centos7升级curl

因为旧版本的curl，不支持--retry-connrefused特征，curl 7.52.0版本以上才支持，通过curl -V查看，发现curl的版本低于7.52，所以对curl进行版本升级，步聚发下：
1 安装libnghttp2.so.14依赖

rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/Packages/l/libnghttp2-1.6.0-1.el6.1.x86_64.rpm

2 安装curl的repo，如果网速的关系，可以先下载好repo的安装包

rpm -ivh http://www.city-fan.org/ftp/contrib/yum-repo/rhel7/x86_64/city-fan.org-release-2-1.rhel7.noarch.rpm

3 修改该repo的enable为1，vim /etc/yum.repos.d/city-fan.org.repo（找到安装的repo），这里修改[city-fan.org]的enable为1即可

[city-fan.org]
name=city-fan.org repository for Red Hat Enterprise Linux (and clones) $releasever ($basearch)
#baseurl=http://mirror.city-fan.org/ftp/contrib/yum-repo/rhel$releasever/$basearch
mirrorlist=http://mirror.city-fan.org/ftp/contrib/yum-repo/mirrorlist-rhel$releasever
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-city-fan.org

[city-fan.org-debuginfo]
name=city-fan.org debuginfo repository for Red Hat Enterprise Linux (and clones) $releasever ($basearch)
#baseurl=http://www.city-fan.org/ftp/contrib-debug/rhel$releasever/$basearch
mirrorlist=http://www.city-fan.org/ftp/contrib-debug/mirrorlist-rhel$releasever
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-city-fan.org

[city-fan.org-source]
name=city-fan.org source repository for Red Hat Enterprise Linux (and clones) $releasever
#baseurl=http://mirror.city-fan.org/ftp/contrib/yum-repo/rhel$releasever/source
mirrorlist=http://mirror.city-fan.org/ftp/contrib/yum-repo/source-mirrorlist-rhel$releasever
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-city-fan.org

4 更新curl

yum update curl --enablerepo=city-fan.org -y

5 最后查看curl的版本

[root@VM-56-4-centos ~]# curl -V
curl 7.73.0 (x86_64-redhat-linux-gnu) libcurl/7.73.0 NSS/3.44 zlib/1.2.7 libpsl/0.7.0 (+libicu/50.1.2) libssh2/1.9.0 nghttp2/1.6.0
Release-Date: 2020-10-14
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp 
Features: AsynchDNS GSS-API HTTP2 HTTPS-proxy IPv6 Kerberos Largefile libz Metalink NTLM NTLM_WB PSL SPNEGO SSL UnixSockets