docker inspect does not show IPv6 addresses

[MalteJ]

"docker inspect mycontainer" does not show container's IPv6 address:

"NetworkSettings": {
    "Bridge": "docker0",
    "Gateway": "172.17.42.1",
    "IPAddress": "172.17.0.8",
    "IPPrefixLen": 16,
    "PortMapping": null,
    "Ports": {}
},

the ifconfig output inside the container:

root@5f54af0a7db0:/# ifconfig
eth0  Link encap:Ethernet  HWaddr 96:79:64:33:6f:17
      inet addr:172.17.0.9  Bcast:0.0.0.0  Mask:255.255.0.0
      inet6 addr: 2a11:4f8:140:2425:9479:64ff:fe33:6f17/64 Scope:Global
      inet6 addr: fe80::9479:64ff:fe33:6f17/64 Scope:Link
      UP BROADCAST RUNNING  MTU:1500  Metric:1
      RX packets:13 errors:0 dropped:4 overruns:0 frame:0
      TX packets:7 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:1000
      RX bytes:1490 (1.4 KB)  TX bytes:586 (586.0 B)

It would be nice to have a key "IPv6Address" under "NetworkSettings".

[tianon]

I think this would be an excellent justification for just switching to "IPAddresses" as an array, especially since having multiple IPv4 addresses is really not at all uncommon but even more importantly, having multiple IPv6 addresses is not only common, it's actually recommended to do so in the standards.

[cnf]

+1 on this one, I also would really need to get the IPv6 addresses exposed in network settings.

[MalteJ]

I have looked into this. The docker inspect only shows the IP address that was assigned to the container during creation. If you change the IP while the container is running, the IP in docker inspect will not get updated.
For container networking docker relies on libcontainer. libcontainer currently does not have a method to retrieve the container's current IP addresses.
That said I am currently working on an IPv6 implementation for docker, so that every container gets one IPv4 and one IPv6 address during creation (docker run --ipv6=true). Both addresses will be displayed by docker inspect given that they are known while creating the container.

[MalteJ]

One word about multiple IP addresses:
It is a big change in the code. In docker itself as well as in libcontainer.
I would go for one IPv4 and one IPv6 first and later try to extend it to multiple IPs.

[asbjornenge]

👍 Any progress ? I need it for my DNS service discovery goodness 🐰 🚀

[MalteJ]

You can calculate the link-local IPv6 from the container's mac address.
The global IPv6 is currently not inspectable.

[MalteJ]

Opened a Pull Request that is implementing this: #8947

[asbjornenge]

@MalteJ 👍 awesome!

[GM-Alex]

Any news on making the global IPv6 inspectable?

[jessfraz]

It will be 1.5 :)

On Wednesday, January 28, 2015, Alexander Schneider <
notifications@github.com> wrote:

Any news on making the global IPv6 inspectable?

—
Reply to this email directly or view it on GitHub
#7042 (comment).

[GM-Alex]

@jfrazelle Great! 👍