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更新Ubuntu软件源

原有的软件源的存储路径是/etc/apt/sources.list，文件内容如下。

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://archive.ubuntu.com/ubuntu/ focal main restricted
# deb-src http://archive.ubuntu.com/ubuntu/ focal main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu/ focal-updates main restricted
# deb-src http://archive.ubuntu.com/ubuntu/ focal-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu/ focal universe
# deb-src http://archive.ubuntu.com/ubuntu/ focal universe
deb http://archive.ubuntu.com/ubuntu/ focal-updates universe
# deb-src http://archive.ubuntu.com/ubuntu/ focal-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu/ focal multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ focal multiverse
deb http://archive.ubuntu.com/ubuntu/ focal-updates multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ focal-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
# deb-src http://archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu focal partner
# deb-src http://archive.canonical.com/ubuntu focal partner

deb http://security.ubuntu.com/ubuntu/ focal-security main restricted
# deb-src http://security.ubuntu.com/ubuntu/ focal-security main restricted
deb http://security.ubuntu.com/ubuntu/ focal-security universe
# deb-src http://security.ubuntu.com/ubuntu/ focal-security universe
deb http://security.ubuntu.com/ubuntu/ focal-security multiverse
# deb-src http://security.ubuntu.com/ubuntu/ focal-security multiverse

1. 备份原有软件源，命令如下。

cp /etc/apt/sources.list /etc/apt/sources.list.bak

2. 修改软件源sources.list的内容，修改指令如下。

vi /etc/apt/sources.list

# 清华源
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security multiverse

# 阿里源
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

3. 修改后sources.list内容如下。

deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security multiverse

deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

4. 更新sources.list，命令如下。

apt-get update

# 显示结果
Get:1 http://mirrors.aliyun.com/ubuntu bionic InRelease [242 kB]
Get:2 http://mirrors.aliyun.com/ubuntu bionic-security InRelease [88.7 kB]
Get:3 http://mirrors.aliyun.com/ubuntu bionic-updates InRelease [88.7 kB]
Get:4 http://mirrors.aliyun.com/ubuntu bionic-proposed InRelease [242 kB]
Get:5 http://mirrors.aliyun.com/ubuntu bionic-backports InRelease [74.6 kB]
Get:6 http://mirrors.aliyun.com/ubuntu bionic/multiverse Sources [216 kB]
Get:7 http://mirrors.aliyun.com/ubuntu bionic/restricted Sources [5823 B]
Get:8 http://mirrors.aliyun.com/ubuntu bionic/main Sources [1063 kB]
Get:9 http://mirrors.aliyun.com/ubuntu bionic/universe Sources [11.5 MB]
Get:10 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial InRelease [247 kB]
Get:11 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-updates InRelease [99.8 kB]
Get:12 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-backports InRelease [97.4 kB]
Get:13 http://mirrors.aliyun.com/ubuntu bionic/multiverse amd64 Packages [186 kB]
Get:14 http://mirrors.aliyun.com/ubuntu bionic/restricted amd64 Packages [13.5 kB]
Get:15 http://mirrors.aliyun.com/ubuntu bionic/main amd64 Packages [1344 kB]
Get:16 http://mirrors.aliyun.com/ubuntu bionic/universe amd64 Packages [11.3 MB]
Get:17 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-security InRelease [99.8 kB]
Get:18 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial/main amd64 Packages [1558 kB]
Get:19 http://mirrors.aliyun.com/ubuntu bionic-security/multiverse Sources [8784 B]
Get:20 http://mirrors.aliyun.com/ubuntu bionic-security/universe Sources [365 kB]
Get:21 http://mirrors.aliyun.com/ubuntu bionic-security/main Sources [331 kB]
Get:22 http://mirrors.aliyun.com/ubuntu bionic-security/restricted Sources [26.8 kB]
Get:23 http://mirrors.aliyun.com/ubuntu bionic-security/main amd64 Packages [2628 kB]
Get:24 http://mirrors.aliyun.com/ubuntu bionic-security/multiverse amd64 Packages [21.1 kB]
Get:25 http://mirrors.aliyun.com/ubuntu bionic-security/restricted amd64 Packages [829 kB]
Get:26 http://mirrors.aliyun.com/ubuntu bionic-security/universe amd64 Packages [1478 kB]
Get:27 http://mirrors.aliyun.com/ubuntu bionic-updates/universe Sources [598 kB]
Get:28 http://mirrors.aliyun.com/ubuntu bionic-updates/restricted Sources [30.2 kB]
Get:29 http://mirrors.aliyun.com/ubuntu bionic-updates/multiverse Sources [18.2 kB]
Get:30 http://mirrors.aliyun.com/ubuntu bionic-updates/main Sources [655 kB]
Get:31 http://mirrors.aliyun.com/ubuntu bionic-updates/main amd64 Packages [3067 kB]
Get:32 http://mirrors.aliyun.com/ubuntu bionic-updates/universe amd64 Packages [2256 kB]
Get:33 http://mirrors.aliyun.com/ubuntu bionic-updates/multiverse amd64 Packages [29.0 kB]
Get:34 http://mirrors.aliyun.com/ubuntu bionic-updates/restricted amd64 Packages [863 kB]
Get:35 http://mirrors.aliyun.com/ubuntu bionic-proposed/multiverse Sources [2053 B]
Get:36 http://mirrors.aliyun.com/ubuntu bionic-proposed/main Sources [95.0 kB]
Get:37 http://mirrors.aliyun.com/ubuntu bionic-proposed/universe Sources [9634 B]
Get:38 http://mirrors.aliyun.com/ubuntu bionic-proposed/restricted Sources [14.4 kB]
Get:39 http://mirrors.aliyun.com/ubuntu bionic-proposed/main amd64 Packages [236 kB]
Get:40 http://mirrors.aliyun.com/ubuntu bionic-proposed/universe amd64 Packages [20.8 kB]
Get:41 http://mirrors.aliyun.com/ubuntu bionic-proposed/restricted amd64 Packages [171 kB]
Get:42 http://mirrors.aliyun.com/ubuntu bionic-proposed/multiverse amd64 Packages [2329 B]
Get:43 http://mirrors.aliyun.com/ubuntu bionic-backports/main Sources [5862 B]
Get:44 http://mirrors.aliyun.com/ubuntu bionic-backports/universe Sources [7129 B]
Get:45 http://mirrors.aliyun.com/ubuntu bionic-backports/universe amd64 Packages [12.6 kB]
Get:46 http://mirrors.aliyun.com/ubuntu bionic-backports/main amd64 Packages [11.6 kB]
Get:47 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial/restricted amd64 Packages [14.1 kB]
Get:48 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial/universe amd64 Packages [9827 kB]
Get:49 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial/multiverse amd64 Packages [176 kB]
Get:50 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-updates/multiverse amd64 Packages [26.2 kB]
Get:51 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-updates/main amd64 Packages [2560 kB]
Get:52 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-updates/universe amd64 Packages [1544 kB]
Get:53 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-updates/restricted amd64 Packages [16.4 kB]
Get:54 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-backports/universe amd64 Packages [12.7 kB]
Get:55 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-backports/main amd64 Packages [10.9 kB]
Get:56 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-security/multiverse amd64 Packages [8820 B]
Get:57 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-security/main amd64 Packages [2051 kB]
Get:58 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-security/restricted amd64 Packages [15.9 kB]
Get:59 http://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-security/universe amd64 Packages [984 kB]
Fetched 59.6 MB in 41s (1446 kB/s)
Reading package lists... Done

5. 完成更换Ubuntu软件源操作。
6. 在Docker中换源（不使用vim）。

echo "">/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted">>/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted">>/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial universe">>/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates universe">>/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial multiverse">>/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates multiverse">>/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse">>/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted">>/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security universe">>/etc/apt/sources.list
echo "deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security multiverse">>/etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse">>/etc/apt/sources.list
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse">>/etc/apt/sources.list
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse">>/etc/apt/sources.list
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse">>/etc/apt/sources.list
echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse">>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse">>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse">>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse">>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse">>/etc/apt/sources.list
echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse">>/etc/apt/sources.list