Docker for Mac: build proxy settings when using remote context

Question

I have a Linux system where I run docker. This system can only access the internet via corporate proxy.

For docker run I had to set the proxy config in my ~/.docker/config.json:

{
  "proxies": {
    "default": {
      "httpProxy": "...",
      "httpsProxy": "...",
      "noProxy": "..."
    }
  }
}

To use proxy in docker build I had to set env vars in /etc/sysconfig/docker:

HTTP_PROXY="..."
HTTPS_PROXY="..."
NO_PROXY="..."

This system works fine and I can run docker run and docker build, both using the proxy settings.

Now I want to run my local docker on MacOS against this remote machine via docker context.

I created a context that connects via ssh to the remote host:

docker context create remote \
   --description "remote execution" \
   --docker "host=ssh://docker.remote"

I also set the proxy settings in my local ~/.docker/config.json:

{
  "proxies": {
    "remote": {
      "httpProxy": "...",
      "httpsProxy": "...",
      "noProxy": "..."
    }
  }
}

A docker info shows the proxy is used and for docker run that also is true and I can access the internet from within containers.

Any attempt to access the internet though fails when calling docker build.

Is there some other file I need to change, just like the sysconfig file on linux?

---

I do have an ugly workaround now. I found that setting the proxy via --build-arg acutally works. To not always have to set the --build-args manually, I added an override for the docker command in my .bashrc. Ugly but working.

function docker {
  if [ "$1" == "build" ] && [ "$#" -gt 1 ]; then
    echo "Building with proxy!"
    /usr/local/bin/docker "$@" \
      --build-arg http_proxy="..." \
      --build-arg https_proxy="..." \
      --build-arg no_proxy="..."
  else
    /usr/local/bin/docker "$@"
  fi
}

Answer 1

It seems an issue with docker backward compatibility with older versions settings, I've tried every single solution online for setting a proxy that affects docker build command, the only thing that worked for me:

1. Open Troubleshoot settings (bug button) from Docker Desktop

2. Clean/Purge data

4. Optionally Reset to factory defaults

5. Purge every thing, NOTE that you will lose all your local images, containers, volumes.

6. After docker restarts set the proxy from Docker Desktop in Settings > Resources > Proxies, and it will take effect.

But I can't risk losing my data

the tedious solution unfortunately is setting HTTP_PROXY & HTTPS_PROXY env variables for every terminal session/process before executing docker commands:

Mac / Linux:

export HTTP_PROXY=...
export HTTPS_PROXY=...

Windows:

set HTTP_PROXY=...
set HTTPS_PROXY=...