命令替换
用以下命令替换 /etc/yum.repos.d 下的文件

sudo sed -e 's|^metalink=|#metalink=|g' \
         -e 's|^#baseurl=http://download.example/pub/fedora/linux|baseurl=https://mirror.nju.edu.cn/fedora|g' \
         -i.bak \
         /etc/yum.repos.d/fedora.repo \
         /etc/yum.repos.d/fedora-modular.repo \
         /etc/yum.repos.d/fedora-updates.repo \
         /etc/yum.repos.d/fedora-updates-modular.repo

手动替换

fedora 仓库 (/etc/yum.repos.d/fedora.repo)

[fedora]
name=Fedora $releasever - $basearch
failovermethod=priority
baseurl=https://mirror.nju.edu.cn/fedora/releases/$releasever/Everything/$basearch/os/
metadata_expire=28d
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

updates 仓库 (/etc/yum.repos.d/fedora-updates.repo)

[updates]
name=Fedora $releasever - $basearch - Updates
failovermethod=priority
baseurl=https://mirror.nju.edu.cn/fedora/updates/$releasever/Everything/$basearch/
enabled=1
gpgcheck=1
metadata_expire=6h
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

fedora-modular 仓库 (/etc/yum.repos.d/fedora-modular.repo)

[fedora-modular]
name=Fedora Modular $releasever - $basearch
failovermethod=priority
baseurl=https://mirror.nju.edu.cn/fedora/releases/$releasever/Modular/$basearch/os/
enabled=1
metadata_expire=7d
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

updates-modular 仓库 (/etc/yum.repos.d/fedora-updates-modular.repo)

[updates-modular]
name=Fedora Modular $releasever - $basearch - Updates
failovermethod=priority
baseurl=https://mirror.nju.edu.cn/fedora/updates/$releasever/Modular/$basearch/
enabled=1
gpgcheck=1
metadata_expire=6h
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

参考网站：https://mirror.nju.edu.cn/mirrorz-help/fedora/?mirror=NJU