这是我第一次接触 Debian，我需要一个 docker。我一直在关注https://docs.docker.com/engine/installation/linux/debian/安装它，但是我遇到了错误：
% apt-get update
Ign cdrom://[Debian GNU/Linux 8.3.0 _Jessie_ - Official amd64 DVD Binary-1 20160123-19:03] jessie InRelease
Ign cdrom://[Debian GNU/Linux 8.3.0 _Jessie_ - Official amd64 DVD Binary-1 20160123-19:03] jessie Release.gpg
Ign cdrom://[Debian GNU/Linux 8.3.0 _Jessie_ - Official amd64 DVD Binary-1 20160123-19:03] jessie Release
Ign cdrom://[Debian GNU/Linux 8.3.0 _Jessie_ - Official amd64 DVD Binary-1 20160123-19:03] jessie/contrib amd64 Packages/DiffIndex
Ign cdrom://[Debian GNU/Linux 8.3.0 _Jessie_ - Official amd64 DVD Binary-1 20160123-19:03] jessie/main amd64 Packages/DiffIndex
Ign cdrom://[Debian GNU/Linux 8.3.0 _Jessie_ - Official amd64 DVD Binary-1 20160123-19:03] jessie/contrib Translation-en_CA
Ign cdrom://[Debian GNU/Linux 8.3.0 _Jessie_ - Official amd64 DVD Binary-1 20160123-19:03] jessie/main Translation-en_CA
Hit http://security.debian.org jessie/updates InRelease
Hit http://security.debian.org jessie/updates/main Sources
Hit http://security.debian.org jessie/updates/contrib Sources
Hit http://security.debian.org jessie/updates/main amd64 Packages
Hit http://security.debian.org jessie/updates/contrib amd64 Packages
Hit http://security.debian.org jessie/updates/contrib Translation-en
Hit http://security.debian.org jessie/updates/main Translation-en
Reading package lists... Done
% apt-get install apt-transport-https ca-certificates
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package apt-transport-https
%
更新
根据建议，我更新了/etc/apt/sources.list：
% cat /etc/apt/sources.list
#
deb http://ftp.de.debian.org/debian/ jessie main
deb-src http://ftp.de.debian.org/debian/ jessie main
deb http://security.debian.org/ jessie/updates main
deb-src http://security.debian.org/ jessie/updates main
deb http://ftp.de.debian.org/debian/ jessie-updates main
deb-src http://ftp.de.debian.org/debian/ jessie-updates main
但是apt-cache show apt-transport-https返回错误（无法找到包 apt-transport-https），and apt-get install apt-transport-https返回与之前相同的失败。
我应该注意什么来解决这个问题？谢谢。
答案1
软件包 apt-transport-https 在官方存储库中可用（已使用 检查apt-cache show apt-transport-https），但似乎没有包含在您用于安装的 DVD 中。
修改 sources.list 以使用互联网存储库而不是 DVD 应该可以解决这个问题。另请参阅此处： https://unix.stackexchange.com/questions/16370/apt-get-prompts-for-cds-when-installing-packages-how-do-i-make-it-stop