Documentation not clear around `config.json` proxy configuration and buildkit

[tavlima]

Problem description

I'm trying to figure out if it is possible and, if so, what is the correct way to pass proxy settings to docker buildx through the config.json.

I tried to do it like the example in #4686, replacing the tcp://example.docker.com:2376 in the aforementioned example by the URL for my remote buildkitd daemon, tcp://buildkitd.mycorp.example.com:1234. This didn't work.

FWIW, that buildkitd URL is same I used while creating the builder: docker buildx create --name my_remote_builder --driver remote tcp://buildkitd.mycorp.example.com:1234

Problem location

I couldn't find the information I wanted. I expected to find it near the proxy documentation.

It would be great to explain there not only the relationship between the default block and any other custom hosts you may have there, as briefly explained here (not clear enough, IMHO).

It would also go a long way to highlight whether it works when using buildx or not, since that is supposed to be a first class, AFAIK.