epel and ius sources provide a lot of useful software.

CentOS uses the yum package manager, and the software source configuration file of Yum is stored in the directory / etc/yum.repos.d /.

Back up and delete all CentOS-*.repo entries, and create centos.repo file:

[base]
name=CentOS-$releasever - Base
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/centos/$releasever/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

#released updates
[updates]
name=CentOS-$releasever - Updates
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/centos/$releasever/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/centos/$releasever/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/centos/$releasever/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

Note that RPM-GPG-KEY-CENTOS-7 is used here to verify the software source. This file has been downloaded by default. Otherwise, it can be obtained from the Tsinghua source root directory.

Perform the yum update update.

Execute Yum install EPEL release, which will automatically set up new software source and install RPM-GPG-KEY-EPEL-7.

Back up and remove all epel*.repo entries and create the epel.repo file:

[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/epel/7/$basearch
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=$basearch
failovermethod=priority
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7

[epel-debuginfo]
name=Extra Packages for Enterprise Linux 7 - $basearch - Debug
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/epel/7/$basearch/debug
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-debug-7&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=1

[epel-source]
name=Extra Packages for Enterprise Linux 7 - $basearch - Source
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/epel/7/SRPMS
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-source-7&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=1

Perform the yum update update.

The ius source needs to https://ius.io/GettingStarted/ Download rpm package, link is https://centos7.iuscommunity.org/ius-release.rpm. This step can't be used IPv6 traffic free.

After downloading, install yum install ius-release.rpm, and then install it similar to epel. After removing ius*.repo by backup, create the ius.repo file:

[ius]
name=IUS Community Packages for Enterprise Linux 7 - $basearch
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/ius/stable/CentOS/7/$basearch
#mirrorlist=https://mirrors.iuscommunity.org/mirrorlist?repo=ius-centos7&arch=$basearch&protocol=http
failovermethod=priority
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/IUS-COMMUNITY-GPG-KEY

[ius-debuginfo]
name=IUS Community Packages for Enterprise Linux 7 - $basearch - Debug
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/ius/stable/CentOS/7/$basearch/debuginfo
#mirrorlist=https://mirrors.iuscommunity.org/mirrorlist?repo=ius-centos7-debuginfo&arch=$basearch&protocol=http
failovermethod=priority
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/IUS-COMMUNITY-GPG-KEY

[ius-source]
name=IUS Community Packages for Enterprise Linux 7 - $basearch - Source
baseurl=https://mirrors6.tuna.tsinghua.edu.cn/ius/stable/CentOS/7/SRPMS
#mirrorlist=https://mirrors.iuscommunity.org/mirrorlist?repo=ius-centos7-source&arch=source&protocol=http
failovermethod=priority
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/IUS-COMMUNITY-GPG-KEY

Perform the yum update update.