Docker Networking已禁用:警告:禁用IPv4转发.网络无法正常工作

Question

主机中的容器"突然"失去与外部世界容器的连接.然而,一些主机被刷新,突然我们遇到以下情况:

1. 主机可以与其他主机通信.
2. 在主机中运行的容器无法与其他主机通信.

这是一个例子:

[root@pprdespap322 deploy]# ping ci.docker.company.net
PING pprdespap324.corp.company.net (10.137.55.22) 56(84) bytes of data.
64 bytes from pprdespap324.corp.company.net (10.137.55.22): icmp_seq=1 ttl=64 time=0.282 ms
64 bytes from pprdespap324.corp.company.net (10.137.55.22): icmp_seq=2 ttl=64 time=0.341 ms
^C
--- pprdespap324.corp.company.net ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.282/0.311/0.341/0.034 ms

现在,从容器本身,我们无法ping同一主机:

[root@pprdespap322 deploy]# docker run -ti quay.io/coreos/registry ping ci.docker.company.net
WARNING: IPv4 forwarding is disabled. Networking will not work.
ping: unknown host ci.docker.company.net

我第一次看到这个警告是在Docker的初始版本中......拥有Docker 1.9.1和1.10.3,如何解决这个问题？

Answer 1

我查看了http://chrisgilmerproj.github.io/ubuntu/network/docker/2013/09/05/ipv4-forwarding-and-docker.html,它帮助我解决了主机上的问题.

我在/etc/sysctl.conf中添加了以下内容:

net.ipv4.ip_forward=1

然后我重新启动了网络服务并验证了设置:

[root@pprdespap322 deploy]#  systemctl restart network
[root@pprdespap322 deploy]# sysctl net.ipv4.ip_forward
net.ipv4.ip_forward = 1
[root@pprdespap322 deploy]# docker run -ti quay.io/coreos/registry ping ci.docker.company.net
PING pprdespap324.corp.company.net (10.137.55.22) 56(84) bytes of data.
64 bytes from pprdespap324.corp.company.net (10.137.55.22): icmp_seq=1 ttl=63 time=0.329 ms
64 bytes from pprdespap324.corp.company.net (10.137.55.22): icmp_seq=2 ttl=63 time=0.306 ms
^C
--- pprdespap324.corp.company.net ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.306/0.317/0.329/0.021 ms

现在所有容器都可以与外界容器通信!

Answer 2

尝试重新启动 Docker 服务。

例如对于 Ubuntu：

$ sudo systemctl restart docker

Answer 3

尝试--network=host与docker run命令一起添加以解决此问题。

https://medium.com/@gchandra/docker-ipv4-forwarding-is-disabled-8499ce59231e

Answer 4

解决了我的问题，重新启动网络。

systemctl restart network