Cannot access index

[drnic]

$ export DOCKER_HOST=localhost
$ docker run ubuntu:13.04 echo hello world
Unable to find image 'ubuntu:13.04' (tag: 13.04) locally
Pulling repository ubuntu
2014/02/15 06:53:14 pull: Get https://index.docker.io/v1/repositories/ubuntu/images: dial tcp: lookup index.docker.io on [10.235.3.253]:53: no such host

But normal curl works from the same machine:

$ curl https://index.docker.io/v1/repositories/ubuntu/images
[{"checksum": "tarsum+sha256:8a76588341423e26d1f422208c5b3667a281594a203c0c2bdf71e17ffabd91bf...

[drnic]

The DNS IP address mentioned is the first of two in resolv.conf

$ cat /etc/resolv.conf 
domain compute-1.internal
search compute-1.internal
nameserver 10.235.3.253
nameserver 172.16.0.23

Perhaps docker doesn't move on to the 2nd nameserver?

@crosbymichael should docker use all nameservers in /etc/resolv.conf? Or do I have to explicitly setup docker -d -dns to duplicate the nameservers?

[drnic]

@crosbymichael for your reference, the first DNS is an internal BOSH DNS; the 2nd one should be an AWS public DNS.

$ dig @172.16.0.23 +short index.docker.io
edge-dockerio.dotcloud.com.
54.234.135.251
54.224.119.89

[drnic]

Hmm I explicitly added the two nameservers to docker with -dns but still not finding the docker index:

$ ps ax
...
 5942 ?        S<l    0:00 docker -d -p /var/vcap/sys/run/docker_server/docker_server.pid -g /var/vcap/data/docker -H tcp://127.0.0.1:4243 -H unix:///var/vcap/sys/run/docker_server/docker.sock -dns 10.235.3.253 -dns 172.16.0.23 --restart=true --mtu=0

$ docker run ubuntu:13.04 echo hello world
Unable to find image 'ubuntu:13.04' (tag: 13.04) locally
Pulling repository ubuntu
2014/02/15 07:13:42 pull: Get https://index.docker.io/v1/repositories/ubuntu/images: dial tcp: lookup index.docker.io on [10.235.3.253]:53: no such host

[drnic]

Ok, I don't think I know what's going on. I removed -dns 10.235.3.253 to try to force docker to use the public DNS -dns 172.16.0.23 but it is still using the private DNS and erroring.

[drnic]

@hatofmonkeys do you have public DNS working in your https://github.com/hatofmonkeys/decker-release work?

[crosbymichael]

@drnic let me check

[drnic]

To confirm, if I remove the first private nameserver from /etc/resolv.conf and restart docker -d then it works normally and can resolve public hostnames from the public DNS.

[drnic]

@crosbymichael how does docker resolve DNS? A standard golang library or something specifically written for docker?

[crosbymichael]

@drnic docker does not resolve dns, if your host system has a resolv.conf it will use that, if not than it will inject 8.8.8.8. We don't resolve anything.

[drnic]

Ok. Hmm, ideas why it's stopping at the first nameserver and not trying the second one?

/CC @frodenas

On Tue, Feb 18, 2014 at 9:43 AM, Michael Crosby notifications@github.com wrote:

@drnic docker does not resolve dns, if your host system has a resolv.conf it will use that, if not than it will inject 8.8.8.8. We don't resolve anything.

Reply to this email directly or view it on GitHub: https://github.com/drnic/docker-server-boshrelease/issues/2#issuecomment-35411412

[crosbymichael]

Off the top of my head I thought it will take the full resolv.conf but you or I will have to look in the code to make sure.

[drnic]

I'll use it as an excuse for a code reading exercise. See if I can figure out if there's anything in docker/go that might be related.

On Tue, Feb 18, 2014 at 9:45 AM, Michael Crosby notifications@github.com wrote:

Off the top of my head I thought it will take the full resolv.conf but you or I will have to look in the code to make sure.

Reply to this email directly or view it on GitHub: https://github.com/drnic/docker-server-boshrelease/issues/2#issuecomment-35411643

[crosbymichael]

The container's resolv.conf should live in /var/lib/docker/containers//resolv.conf if you want to see what it looks like

[frodenas]

@drnic At your PowerDns instance, add an external recursor at /var/vcap/jobs/powerdns/config/pdns.conf:

recursor=172.16.0.23