Docker registry on RHEL7.1

Here is some quick notes on setting up docker registry on RHEL7.1

We can pretty much follow the excellent recipe of Nik van der Ploeg[1] for Ubuntu except adjusting file paths for nginx and tls/CA/certs according to RHEL7. See also the command update-ca-trust instead of update-ca-certificates on Ubuntu.

Unfortunately docker-registry from redhat does not seem to come direclty prepared for being searched. In order for tha search API-endpoint to work the following variables must be added to the file /etc/sysconfig/docker

SEARCH_BACKEND=sqlalchemy
SQLALCHEMY_INDEX_DATABASE=sqlite:////tmp/docker-registry.db

It also turns out that the python module that actually does that work is not included in the dependency list of docker-registry, so it also needs to be installed.

[root@docker-registry lib]# yum install python-sqlalchemy

Check now that you do get some JSON and not 404 when

[root@docker-registry lib]# curl http://localhost:5000/v1/search

Now we can go on and add the local registry to /etc/sysconfig/docker of the hosts that will use it.

ADD_REGISTRY='--add-registry registry.access.redhat.com --add-registry docker-registry.uio.no:8080'

[1] https://www.digitalocean.com/community/tutorials/how-to-set-up-a-private-docker-registry-on-ubuntu-14-04