Docker container cannot resolve dns - dns

Question

I'm trying to configure my docker container to see my local private rpm repository through http. It cannot resolve the dns name and I'm probably not setting up DNS correctly on the host CENTOS 6.5 VM.
http://
172.17.42.1
/repository/CENTOS/6/nginx/x86_64/repodata/repomd.xml:
[Errno 14] PYCURL ERROR 7 - > "couldn't connect to host"
bash-4.1# more /etc/yum.repos.d/nginx.repo
[nginx]
name=nginx repo
baseurl=http://
172.17.42.1/repository/CENTOS/$releasever/nginx/$basearch/
(can't connect to host)
gpgcheck=0
enabled=1
The container /etc/resolv.conf contains this
bash-4.1# cat /etc/resolv.conf
nameserver 192.168.64.2
nameserver 192.168.64.129
nameserver 127.0.0.1
search localdomain eadis.local
When I try to add the domainname to the IP address it does not
resolve.
Docker container IP address
eth0 Link encap:Ethernet HWaddr 7E:EB:4C:25:F4:DA
inet addr:172.17.0.7 Bcast:0.0.0.0 Mask:255.255.0.0
Host VM Docker server
docker0 Link encap:Ethernet HWaddr FE:EF:63:A8:65:5C
inet addr:
172.17.42.1
Bcast:0.0.0.0 Mask:255.255.0.0
eth3 Link encap:Ethernet HWaddr 00:0C:29:10:0A:77
inet addr:192.168.64.129 Bcast:192.168.64.255 Mask:255.255.255.0
[root#centos named]# cat /etc/resolv.conf
domain localdomain
search localdomain eadis.local
nameserver 192.168.64.129
nameserver 192.168.64.2

Answer 1

When you run your container with --net or --network, docker will use a self DNS server to discover services that runs with it. All DNS queries are sent to the docker engine.
In normal times (when using default network) you can use the --dns option on your run command. But when you run your images with a self-defined network, you must add your customize resolv.conf file to the container. You make one on your system and name it custom-resolv.conf.
In this file you can add your custom dns address and add it to your container.
nameserver 1.0.0.1
nameserver 4.2.2.4
Then you must add this small part to your run command:
-v /path/to/file/custom-resolv.conf:/etc/resolv.conf:ro
Use ro for read-only volume mapping. When your container is started, you can exec to your container and check the /etc/resolv.conf file which must be the same as custom-resolv.conf.
Now all of your DNS requests are sent to your DNS server.