The fact that Docker images are downloaded from docker hub if not found in local, where is that configured?
So you want to block downloading from the docker hub?
if that’s the case you could set the HTTP_PROXY environment variable to something random that will not work, then explicitly tell the engine only to look at your internal registry something like
Environment="HTTP_PROXY=http://proxy.example.com:80/"
Environment="NO_PROXY=localhost,127.0.0.0/8,docker-registry.somecorporation.com"
Otherwise it’s hard coded I believe.yep, here is a similar question on stackoverflow