What is the proper way to fix `error: did not detect an --insecure-registry argument on the Docker daemon` while running `oc cluster up`?

Question

According to this blog one has to change the docker daemon:

/usr/bin/dockerd --insecure-registry 172.30.0.0/16 -H fd://

but I wonder why the error occurs and how to fix it properly?

Answer 1

This error happens because the oc cluster up command spawns a Docker registry. The 172.30.0.0/16 IP range is probably corresponding to your Docker bridge network. As the registry will run in a container with an unpredictable IP address, you must indicate the IP range (--insecure-registry 172.30.0.0/16).