Push to a private registry not receiving / Certificat not accepted

General
1

Hello,

we start yesterday with docker in our company and create a new Image on base of a Image from docker hub.
This Image we would like to push to our Nexus 3 Artifact Repository-Server. We use before the Nexus-Server a apache-http-proxy for the SSL-Capability and of course create a docker Repository in nexus.

We put the server and the ca Certificate in the directory /etc/docker/certs.d/nexus.ourcompany.com but if we try to login to the Repository we get the following result:

docker login https://nexus.ourcompany.com Username: jdoe Password: Email: john.doe@ourcompany.com Error response from daemon: invalid registry endpoint https://nexus.ourcompany.com/v0/: unable to ping registry endpoint https://nexus.ourcompany.com/v0/ v2 ping attempt failed with error: Get https://nexus.ourcompany.com/v2/: Forbidden v1 ping attempt failed with error: Get https://nexus.ourcompany.com/v1/_ping: Forbidden. If this private registry supports only HTTP or HTTPS with an unknown CA certificate, please add–insecure-registry nexus.ourcompanyto the daemon's arguments. In the case of HTTPS, if you have access to the registry's CA certificate, no need for the flag; simply place the CA certificate at /etc/docker/certs.d/nexus.ourcompany.com/ca.crt

and if we try to push the image we get the error
The push refers to a repository [nexus.ourcompany.com/repository/alm] unable to ping registry endpoint https://nexus.ourcompany.com/v0/ v2 ping attempt failed with error: Get https://nexus.ourcompany.com/v2/: Forbidden v1 ping attempt failed with error: Get https://nexus.ourcompany.com/v1/_ping: Forbidden

and for the second case a colluege trace the traffic of the receiving server with tcpdump and the server don’t get any data from the docker-host-server

Becaucse we just start with docker we have no idea what is our mistake in the configuration and we would very thanksful for every hint.
best regards
Dan

2

This smells like firewall / network issues to me. Can you verify that the registry endpoint reachable from the same place the Docker process is running (including inside a VM if it is in there)? Is it an internal DNS that you haven’t configured nameservers for in the Docker daemon? And does it have firewall opened for the proper protocols? (I’m assuming TCP/HTTP in spite of the misleading “ping” line)

3

Hello Nathan,

thanks for your help and your advice it was actual a network problem i didn’t know i need to set the dns-server ip in the DOCKER_ARGS-argument. Now I can login but I get the error that the PUT Method is not allowed but this looks more than a problem with docker and less with docker.