阿里云上搭建 Discourse，无法安装 Docker

大家好，

我想着尝试着在阿里云上安装Discourse。

按照官方30分钟教程安装，但每次进行到安装Docker，这一步：

wget -qO- https://get.docker.io/ | sh

就出下面的问题：

... ...
Get:64 http://security.ubuntu.com trusty-security/main Translation-en [97.0 kB]
Err http://security.ubuntu.com trusty-security/universe i386 Packages          
  404  Not Found [IP: 91.189.88.149 80]
Fetched 4,195 kB in 3min 58s (17.6 kB/s)                                       
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/trusty-security/universe/binary-i386/Packages  404  Not Found [IP: 91.189.88.149 80]

W: Failed to fetch gzip:/var/lib/apt/lists/partial/security.ubuntu.com_ubuntu_dists_trusty-security_main_i18n_Translation-en  Hash Sum mismatch

E: Some index files failed to download. They have been ignored, or old ones used instead.
Reading package lists...
Building dependency tree...
Reading state information...
The following extra packages will be installed:
  aufs-tools cgroup-lite lxc-docker-1.4.1
The following NEW packages will be installed:
  aufs-tools cgroup-lite lxc-docker lxc-docker-1.4.1
0 upgraded, 4 newly installed, 0 to remove and 89 not upgraded.
Need to get 4,519 kB of archives.
After this operation, 15.1 MB of additional disk space will be used.
WARNING: The following packages cannot be authenticated!
  lxc-docker-1.4.1 lxc-docker
E: There are problems and -y was used without --force-yes

请问应该怎么解决啊？谢谢！

我用的是 Ubuntu 14.04 64位的公共镜像