Unable to access docker containers from host over

2019-05-23 14:15发布

问题:

In my Linux network I am unable to reach my docker containers from the host they are running on, over a dedicated macvlan network. All other connections from to this macvlan network are fine.

So basically the setup is:

DOCKER1       eth0  172.0.0.1 (default)
  |           eth1  10.0.0.1  (macvlan)
  CONTAINER1        10.0.0.11 (macvlan)

DOCKER2       eth0  172.0.0.2 (default)
  |           eth1  10.0.0.2  (macvlan)
  CONTAINER2        10.0.0.12 (macvlan)
  • Host DOCKER1 cannot reach CONTAINER1
  • Host DOCKER2 cannot reach CONTAINER2
  • Host DOCKER1 can reach DOCKER2
  • Host DOCKER1 can reach CONTAINER2
  • Host DOCKER2 can reach DOCKER1
  • Host DOCKER2 can reach CONTAINER1
  • All containers can reach each other
  • All other devices in the physical network can reach all
  • All can reach the gateway/internet

How can I make the host reach itss own containers over the macvlan network?

I need specific applications to interact over this network, so using docker exec won't solve my problem ;).

回答1:

The host cannot communicate with local macvlan devices without special support from an external switch. See e.g. this Red Hat documentation which discusses the use of macvlan devices for virtual machines:

However, when a guest virtual machine is configured to use a type='direct' network interface such as macvtap, despite having the ability to communicate with other guests and other external hosts on the network, the guest cannot communicate with its own host.

This situation is actually not an error — it is the defined behavior of macvtap. Due to the way in which the host's physical Ethernet is attached to the macvtap bridge, traffic into that bridge from the guests that is forwarded to the physical interface cannot be bounced back up to the host's IP stack. Additionally, traffic from the host's IP stack that is sent to the physical interface cannot be bounced back up to the macvtap bridge for forwarding to the guests.