Docker Datacenter: Error x509 certificate signed by unknown authority UCP 2.0.0 and DTR 2.1.0 with external certificates

Question

We're trying to install a Docker Datacenter on a 3 node cluster. UCP is installed on all nodes and the cluster is working. The DTR is installed on one of the nodes.

We've already added all certificates in the WebUI of the UCP and the DTR and tried a lot of already given solutions but we're still getting the "signed by unknown authority" error.

It's possible to log into DTR via terminal and push/pull images from any node in our cluster. So it's possible to access DTR. Both WebUIs are accessable and having a verified certificate.

The system has a internal Root-CA and the certificates used by DDC are certified by a subCA.

We're running on RHEL7.2. with UCP 2.0.0, DTR 2.1.0 and Docker 1.12.3-cs4, build 65c6c4c.

What could we do further?

thx for your help.

Answer 1

If you're certain you didn't do anything wrong with certs, you can try the following.

Follow the instructions on this page for your system to let your local docker-engine trust the registry: https://docs.docker.com/datacenter/dtr/2.2/guides/user/access-dtr/

Checklist after that:

• Repository exists. If not, create it in your DTR.
• Image has the name DTR_URL/username/imagename:tag
• Make sure you're logged in to the DTR on your docker-engine. “docker login DTR_URL”.

If you want more specific help, you could try and reach out to Docker or the Docker forum.