Question

我在公司VM上运行docker，主机VM的操作系统是CentOS 6.7

我遇到的问题类似于常见的DNS问题，但我无法找到任何解决方案。

所以......我开始运行python图像的docker容器，如下所示：

docker run -it python:2.7 bash

然后我可以运行ping -c 4 www.google.com

root@46120eb4eacf:/# ping -c 4 www.google.com
PING www.google.com (74.125.239.50): 56 data bytes
64 bytes from 74.125.239.50: icmp_seq=0 ttl=56 time=2.371 ms
64 bytes from 74.125.239.50: icmp_seq=1 ttl=56 time=2.264 ms
64 bytes from 74.125.239.50: icmp_seq=2 ttl=56 time=2.245 ms
64 bytes from 74.125.239.50: icmp_seq=3 ttl=56 time=2.385 ms
--- www.google.com ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max/stddev = 2.245/2.316/2.385/0.062 ms

这很好。但是，当我尝试运行curl命令时，它卡住了

curl http://www.google.com --verbose
* Rebuilt URL to: http://www.google.com/
* Hostname was NOT found in DNS cache
*   Trying 74.125.239.51...
* Connected to www.google.com (74.125.239.51) port 80 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.38.0
> Host: www.google.com
> Accept: */*
>

当我在python shell中发出http请求时会发生同样的事情：

root@46120eb4eacf:/# python
Python 2.7.10 (default, Oct 14 2015, 11:36:56) 
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import urllib2
>>> urllib2.urlopen("http://www.google.com").read()

但是pip install没有问题

root@7fd68dd1f74b:/# pip install Django
Collecting Django
Downloading Django-1.8.5-py2.py3-none-any.whl (6.2MB)
100% |████████████████████████████████| 6.2MB 61kB/s 
Installing collected packages: Django
Successfully installed Django-1.8.5

我注意到的另一个问题是，当我提取ubuntu图片并尝试运行apt-get update时，它也会卡住，不确定它是否相关。

我能让这个工作的唯一方法是将--net=host添加到docker run命令。还有一些关于主持人的其他信息：

uname -a
Linux presidio-client00 2.6.32-573.7.1.el6.x86_64 #1 SMP Tue Sep 22 22:00:00 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

docker version
Client version: 1.7.1
Client API version: 1.19
Go version (client): go1.4.2
Git commit (client): 786b29d
OS/Arch (client): linux/amd64
Server version: 1.7.1
Server API version: 1.19
Go version (server): go1.4.2
Git commit (server): 786b29d
OS/Arch (server): linux/amd64

docker info
Containers: 27
Images: 23
Storage Driver: devicemapper
 Pool Name: docker-252:3-2095948-pool
 Pool Blocksize: 65.54 kB
 Backing Filesystem: extfs
 Data file: /dev/loop0
 Metadata file: /dev/loop1
 Data Space Used: 1.529 GB
 Data Space Total: 107.4 GB
 Data Space Available: 44.33 GB
 Metadata Space Used: 3.666 MB
 Metadata Space Total: 2.147 GB
 Metadata Space Available: 2.144 GB
 Udev Sync Supported: true
 Deferred Removal Enabled: false
 Data loop file: /var/lib/docker/devicemapper/devicemapper/data
 Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
 Library Version: 1.02.95-RHEL6 (2015-09-08)
Execution Driver: native-0.2
Logging Driver: json-file
Kernel Version: 2.6.32-573.7.1.el6.x86_64
Operating System: <unknown>
CPUs: 1
Total Memory: 1.832 GiB
Name: presidio-client00
ID: ZCIY:EKUA:OF52:3N6Z:YDQB:5Z2Y:CDNO:NE2U:ZOBT:6C67:BB5W:KLST
Debug mode (server): true
File Descriptors: 11
Goroutines: 15
System Time: 2015-10-23T14:04:10.337394645-07:00
EventsListeners: 0
Init SHA1: 4193d771605617409a8d2578127b8fbd5754e969
Init Path: /usr/libexec/docker/dockerinit
Docker Root Dir: /var/lib/docker

Answer 1

可能不完全支持在这样一个旧的CentOS（6.7，内核2.6.32）上运行docker。

Docker有一个installation page for... CentOS 7.x (kernel 3.10+)。

这可能解释了连接问题（来自容器内）

docker container network / DNS / Firewall问题

1 个答案: