无法在码头集装箱中安装软件包

Question

下面是我的系统中存在的一些停靠者映像：

root@labadmin-VirtualBox:/home/labadmin# docker images
REPOSITORY   TAG     IMAGE ID            CREATED               SIZE
ubuntu      14.04   1e0c3dd64ccd        13 days ago         187.9 MB
ubuntu     latest   45bc58500fa3        5 weeks ago         126.9 MB

我想在容器中安装“智能工具”。但是它抛出了一个错误，“无法找到包智能工具”如下所示：

root@labadmin-VirtualBox:/home/labadmin# docker run -it 1e0c3dd64ccd
root@b4954826a227:/# apt-get install smartmontools
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package smartmontools
root@b4954826a227:/# exit
exit

但是当我在Ubuntu机器上做同样的事情时，它就开始工作了。

root@labadmin-VirtualBox:/home/labadmin# apt-get install smartmontools
Reading package lists... Done
Building dependency tree       
Reading state information... Done
***smartmontools is already the newest version.***
0 upgraded, 0 newly installed, 0 to remove and 542 not upgraded.
root@labadmin-VirtualBox:/home/labadmin# 

Ubuntu容器和Ubuntu系统有什么不同？是什么阻碍了包被安装在容器中？

我的要求是使用Ubuntu作为基本映像创建一些实用程序的容器：

FROM ubuntu:14.04
RUN apt-get update && apt-get install -y smartmontools

Answer 1

以下程序帮助我解决了这一问题：

root@labadmin-VirtualBox:/home/labadmin# docker run busybox ping -c 2 192.203.230.10
PING 192.203.230.10 (192.203.230.10): 56 data bytes
64 bytes from 192.203.230.10: seq=0 ttl=56 time=66.724 ms
64 bytes from 192.203.230.10: seq=1 ttl=56 time=54.786 ms
--- 192.203.230.10 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 45.815/56.947/66.724 ms

当您试图使用容器到google.com时，由于DNS问题，它无法到达。

root@labadmin-VirtualBox:/home/labadmin# docker run busybox nslookup google.com
Server:    8.8.8.8
Address 1: 8.8.8.8

nslookup: can't resolve 'google.com'

查找您的计算机中使用的DNS服务器：

root@labadmin-VirtualBox:/home/labadmin# nm-tool  |grep DNS
    DNS:             172.24.100.50
    DNS:             10.1.100.50

通过添加DNS IP执行相同的操作：

root@labadmin-VirtualBox:/home/labadmin# docker run --dns 172.24.100.50 busybox nslookup google.com
Server:    172.24.100.50
Address 1: 172.24.100.50 indc01.radisys.com

Name:      google.com
Address 1: 2607:f8b0:4009:80c::200e ord36s01-in-x0e.1e100.net
Address 2: 172.217.4.110 ord36s04-in-f14.1e100.net

若要永久解决此问题，请将以下内容添加到新文件中：

root@labadmin-VirtualBox:/home/labadmin# cat /etc/docker/daemon.json
{
    "dns" : ["172.24.100.50", "8.8.8.8"]
}

关于Docker配置的更多信息：https://docs.docker.com/engine/userguide/networking/configure-dns/

重新启动码头服务：

root@labadmin-VirtualBox:/home/labadmin# sudo service docker restart
docker stop/waiting
docker start/running, process 22291

root@labadmin-VirtualBox:/home/labadmin# docker run busybox nslookup google.com
Server:    172.24.100.50
Address 1: 172.24.100.50 indc01.radisys.com

Name:      google.com
Address 1: 2607:f8b0:4009:801::200e ord30s31-in-x0e.1e100.net
Address 2: 172.217.4.238 ord30s31-in-f14.1e100.net

通过运行容器检查它：

root@labadmin-VirtualBox:/home/labadmin# docker run -it e02e811dd08f
/ # ping google.com
PING google.com (172.217.4.238): 56 data bytes
64 bytes from 172.217.4.238: seq=0 ttl=47 time=251.506 ms
64 bytes from 172.217.4.238: seq=1 ttl=47 time=245.621 ms
^C
--- google.com ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 245.621/257.113/272.586 ms
/ #

有关更多信息：https://robinwinslow.uk/2016/06/23/fix-docker-networking-dns/

Answer 2

当您通过手动运行容器进行测试时，不会使用apt-get update更新缓存，从而导致Unable to locate package错误

但是您的Dockerfile示例应该有效