Cannot load certificates via 'magic' url on Ubuntu 16.04.5 LTS

Cannot load certificates via ‘magic’ url on Ubuntu 16.04.5 LTS

  1. Install mitmproxy via tarball from https://snapshots.mitmproxy.org/4.0.4/mitmproxy-4.0.4-linux.tar.gz (download, untar into ‘/opt/mitmproxy’
  2. Launch mitmproxy (/opt/mitmproxy/mitmproxy)
  3. Launch browser (Tried with both Chrome and Firefox)
  4. visit ‘mitm.it’
  5. Expected: ‘Click to install the mitm proxy certificate’ per documentation
    Actual: Error message: “If you can see this, traffic is not passing through mitmproxy.”

I did search this message and found “https://github.com/mitmproxy/mitmproxy/issues/2341” which was closed with no action and referred to https://github.com/mitmproxy/mitmproxy.org/issues/20 which is open.

In the case of google-chrome, setting all_proxy=localhost:8080 prior to launching chrome didn’t seem to help.

This seems like it should be a simple thing and I’m sure I’m just missing something but I’m pretty green re: proxy setup.