今天Docker新搞了一个CentOS镜像，在运行基于该镜像的容器，执行yum命令时，遇到了如下报错：
[root@GC Administrator]# yum install -y yum-utils
Failed to set locale, defaulting to C.UTF-8
CentOS Linux 8 - AppStream 41 B/s | 38 B 00:00
Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist
目前使用
docker pull centos不指定tag，拉取的latest，centos的版本为 8.4.2105[root@GC Administrator]# cat /etc/redhat-release CentOS Linux release 8.4.2105
1. yum镜像源问题
其中 Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist 是yum镜像源的问题，这个问题我在之前的一篇文章中已经总结过解决方案。
CentOS 执行yum命令报错【错误：为仓库 ‘appstream‘ 下载元数据失败: …】
你可以参考上述文章进行解决，你也可以直接运行下面的命令进行解决（上述文章中提到的其中一种方案）
# Centos 8 之前版本
# 以 CentOS 7.9.2009 为例
minorver=7.9.2009
sudo sed -e "s|^mirrorlist=|#mirrorlist=|g" \-e "s|^#baseurl=http://mirror.centos.org/centos/\$releasever|baseurl=https://mirrors.aliyun.com/centos-vault/$minorver|g" \-i.bak \/etc/yum.repos.d/CentOS-*.repo# CentOS 8 版本
# 以 CentOS 8.5.2111 为例
minorver=8.5.2111
sudo sed -e "s|^mirrorlist=|#mirrorlist=|g" \-e "s|^#baseurl=http://mirror.centos.org/\$contentdir/\$releasever|baseurl=https://mirrors.aliyun.com/centos-vault/$minorver|g" \-i.bak \/etc/yum.repos.d/CentOS-*.repo
2. 语言环境问题
其中Failed to set locale, defaulting to C.UTF-8是系统语言环境问题
下面是解决方案：
1）查看本地安装的语言包
[root@GC ~]# locale -a
C
C.utf8
POSIX
2）安装语言包
安装中文语言包：yum install glibc-langpack-zh
安装英文语言包：yum install glibc-langpack-en
我这里只安装了 中文语言包 👇
[root@GC Administrator]# locale -a
C
C.utf8
POSIX
zh_CN
zh_CN.gb18030
zh_CN.gbk
zh_CN.utf8
zh_HK
zh_HK.utf8
zh_SG
zh_SG.gbk
zh_SG.utf8
zh_TW
zh_TW.euctw
zh_TW.utf8
3）设置语言环境
echo "export LC_ALL=zh_CN.utf8" >> /etc/profile
source /etc/profile
从你已安装的语言中，选择你想要设置的语言，我这里选择的是zh_CN.utf8
4）验证语言是否设置成功
[root@GC Administrator]# yum install -y yum-utils
Last metadata expiration check: 0:17:50 ago on 2023年08月25日 星期五 14时06分57秒.
Dependencies resolved.
========================================================================================================================Package Architecture Version Repository Size
========================================================================================================================
Installing:yum-utils noarch 4.0.18-4.el8 baseos 71 k
Installing dependencies:dbus-glib x86_64 0.110-2.el8 baseos 127 kdnf-plugins-core noarch 4.0.18-4.el8 baseos 69 kpython3-dateutil noarch 1:2.6.1-6.el8 baseos 251 kpython3-dbus x86_64 1.2.4-15.el8 baseos 134 kpython3-dnf-plugins-core noarch 4.0.18-4.el8 baseos 234 kpython3-six noarch 1.11.0-8.el8 baseos 38 kTransaction Summary
========================================================================================================================
Install 7 PackagesTotal download size: 925 k
Installed size: 2.3 M
Downloading Packages:
(1/7): dnf-plugins-core-4.0.18-4.el8.noarch.rpm 145 kB/s | 69 kB 00:00
(2/7): dbus-glib-0.110-2.el8.x86_64.rpm 256 kB/s | 127 kB 00:00
(3/7): python3-dateutil-2.6.1-6.el8.noarch.rpm 363 kB/s | 251 kB 00:00
(4/7): python3-dbus-1.2.4-15.el8.x86_64.rpm 404 kB/s | 134 kB 00:00
(5/7): python3-six-1.11.0-8.el8.noarch.rpm 225 kB/s | 38 kB 00:00
(6/7): python3-dnf-plugins-core-4.0.18-4.el8.noarch.rpm 536 kB/s | 234 kB 00:00
(7/7): yum-utils-4.0.18-4.el8.noarch.rpm 299 kB/s | 71 kB 00:00
------------------------------------------------------------------------------------------------------------------------
Total 879 kB/s | 925 kB 00:01
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transactionPreparing : 1/1Installing : python3-six-1.11.0-8.el8.noarch 1/7Installing : python3-dateutil-1:2.6.1-6.el8.noarch 2/7Installing : dbus-glib-0.110-2.el8.x86_64 3/7Running scriptlet: dbus-glib-0.110-2.el8.x86_64 3/7Installing : python3-dbus-1.2.4-15.el8.x86_64 4/7Installing : python3-dnf-plugins-core-4.0.18-4.el8.noarch 5/7Installing : dnf-plugins-core-4.0.18-4.el8.noarch 6/7Installing : yum-utils-4.0.18-4.el8.noarch 7/7Running scriptlet: yum-utils-4.0.18-4.el8.noarch 7/7Verifying : dbus-glib-0.110-2.el8.x86_64 1/7Verifying : dnf-plugins-core-4.0.18-4.el8.noarch 2/7Verifying : python3-dateutil-1:2.6.1-6.el8.noarch 3/7Verifying : python3-dbus-1.2.4-15.el8.x86_64 4/7Verifying : python3-dnf-plugins-core-4.0.18-4.el8.noarch 5/7Verifying : python3-six-1.11.0-8.el8.noarch 6/7Verifying : yum-utils-4.0.18-4.el8.noarch 7/7Installed:dbus-glib-0.110-2.el8.x86_64 dnf-plugins-core-4.0.18-4.el8.noarch python3-dateutil-1:2.6.1-6.el8.noarchpython3-dbus-1.2.4-15.el8.x86_64 python3-dnf-plugins-core-4.0.18-4.el8.noarch python3-six-1.11.0-8.el8.noarchyum-utils-4.0.18-4.el8.noarchComplete!
OK，搞定~
 面向对象分析(OOA)之UML图特点)
