ubuntu16.04TLS軟件源update

網上應該能夠找到不少關於ubuntu源的設置方法，可是若是不搞清楚就隨便設置的話，不只不能起到應有的效果，還會因爲一些問題致使apt不可用。

最正確的更換源的方法應該如系統提示的：

## a.) add 'apt_preserve_sources_list: true' to /etc/cloud/cloud.cfg
## or do the same in user-data
## b.) add sources in /etc/apt/sources.list.d
## c.) make changes to template file /etc/cloud/templates/sources.list.tmpl

這種方法有點沒弄明白在/etc/apt/sources.list.d應該添加的是什麼內容，若是是源文件的話，最後更改的模板又是什麼做用？也沒有去嘗試，有時間會解決一下。

如下提供設置阿里源的方法，其餘源也能夠如法炮製：

1. 首先查看本身的ubuntu系統的codename，這一步很重要，直接致使你更新的源是否對你的系統起效果，查看方法：

    lsb_release -a

    如，個人系統顯示：

No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04.2 LTS
Release: 14.04
Codename: trusty

    顯示了一些ubuntu的版本信息，須要獲得的是Codename，好比，我這裏是trusty

2. 確認阿里源支持：

    登錄如下網頁：http://mirrors.aliyun.com/ubuntu/dists/

    該網頁顯示了阿里雲支持的ubuntu系統下各個Codename版本，確保本身的Codename在該網頁中存在（通常都會有的）

2. 備份系統源：

    cd /etc/apt
    sudo mv sources.list sources.list_bak

3. 添加新的源文件：

    sudo vi sources.list

並添加如下內容：注意，每一行的trusty應該用第一步查看獲得的Codename來代替

# deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted
deb-src http://archive.ubuntu.com/ubuntu xenial main restricted #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial main restricted multiverse universe #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted multiverse universe #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb http://mirrors.aliyun.com/ubuntu/ xenial multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse #Added by software-properties
deb http://archive.canonical.com/ubuntu xenial partner
deb-src http://archive.canonical.com/ubuntu xenial partner
deb http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted multiverse universe #Added by software-properties
deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-security multiverse

4. 保存而且sudo apt-get update，更新成功

5. 如下提供配置腳本：

 1 Codename=$( (lsb_release -a)|awk '{print $2}'|tail -n 1 )
 2 echo "\
 3 deb http://mirrors.aliyun.com/ubuntu/ $Codename main multiverse restricted universe
 4 deb http://mirrors.aliyun.com/ubuntu/ $Codename-backports main multiverse restricted universe
 5 deb http://mirrors.aliyun.com/ubuntu/ $Codename-proposed main multiverse restricted universe
 6 deb http://mirrors.aliyun.com/ubuntu/ $Codename-security main multiverse restricted universe
 7 deb http://mirrors.aliyun.com/ubuntu/ $Codename-updates main multiverse restricted universe
 8 deb-src http://mirrors.aliyun.com/ubuntu/ $Codename main multiverse restricted universe
 9 deb-src http://mirrors.aliyun.com/ubuntu/ $Codename-backports main multiverse restricted universe
10 deb-src http://mirrors.aliyun.com/ubuntu/ $Codename-proposed main multiverse restricted universe
11 deb-src http://mirrors.aliyun.com/ubuntu/ $Codename-security main multiverse restricted universe
12 deb-src http://mirrors.aliyun.com/ubuntu/ $Codename-updates main multiverse restricted universe ">sources.list
13 apt-get update

sudo運行該腳本便可（注意運行以前最好備份以前的sources.list）