Can't reach containers with new 1.10 DNS SD - docker

Question

I've been trying the latest RC's for docker and compose for a few days, and finally, today, the new stable versions (1.10 and 1.6 respectively).
The new networking stuff added in 1.9 has been great so far. But since I upgraded to 1.10rc1 (and so far for every RC and stable), containers in the same user defined network can no longer find each other. In fact, they can't even reach the outside world right now.
A quick example, file test_docker/docker-compose.yml:
version: '2'
services:
db1:
image: mysql
environment:
MYSQL_ALLOW_EMPTY_PASSWORD: yes
db2:
image: mysql
environment:
MYSQL_ALLOW_EMPTY_PASSWORD: yes
This creates two MySQL containers with the official image. According to the compose docs, a new testdocker_default should be created, with both containers automatically connected, which is the case:
docker network inspect testdocker_default
[
{
"Name": "testdocker_default",
"Id": "820f702e8e685567e4f1a8638cd9be305e96e37fcd741306eed6c1cf0d54ba02",
"Scope": "local",
"Driver": "bridge",
"IPAM": {
"Driver": "default",
"Options": null,
"Config": [
{
"Subnet": "172.17.0.0/16",
"Gateway": "172.17.0.1/16"
}
]
},
"Containers": {
"16d5594bdfd11f55d33a207612b8447f6b50ff4be8b42d2313707b06ca618556": {
"Name": "testdocker_db2_1",
"EndpointID": "b6d5ff10fba860c01ac7a6508e56c5e116296cd06ea2158c695897e18fcd50ce",
"MacAddress": "02:42:ac:11:00:03",
"IPv4Address": "172.17.0.3/16",
"IPv6Address": ""
},
"9b8b885dab3b5012c9663cb97a07af66fbe385f92c69a614a4d56bf85305ec3a": {
"Name": "testdocker_db1_1",
"EndpointID": "09e43aef8e14b0e876d47fabe67a3827dc4cea5d44b199113d9ab2678d8ce22a",
"MacAddress": "02:42:ac:11:00:02",
"IPv4Address": "172.17.0.2/16",
"IPv6Address": ""
}
},
"Options": {}
}
]
Now, the documentation also says that the containers should be able to reach each other through db1 and db2, but this is not the case:
root#9b8b885dab3b:/# mysql -h db2 -u root
ERROR 2005 (HY000): Unknown MySQL server host 'db2' (111)
root#9b8b885dab3b:/# mysql -h testdocker_db2_1 -u root
ERROR 2005 (HY000): Unknown MySQL server host 'testdocker_db2_1' (111)
Additionally, neither container is able to reach the internet, unless I explicitly add Google's DNS to the /etc/resolv.conf.
I'm pretty sure I'm doing something wrong here, because I can't find issues raised by other people, but I can't figure out what it is.
Thanks guys!
Edit:
To clarify, containers can ping each other through their IP address, but the hostnames are not resolved.

Answer 1

This issue was reported on GitHub. The suggested workaround for the moment is to disable firewalld altogether.
I will update this answer with a better solution to this issue as soon as one is found.
Edit #1:
Pull request solving this issue (tested for Fedora 23). This PR is already merged with master, for anyone wanting to compile Docker from source.
Couldn't find an expected release date, but I'm guessing it will be released as a patch version in the next couple weeks. Will update this answer again with further information when available.
Edit #2:
Docker's 1.10.1 RC solves this issue. I'll mark this answer as accepted just to close this topic.