Description

The update process used to work through proxies with environment variable "ALL_PROXY". Today, we've realized that the update process have failed for all machines that are being the proxy.

This is what we used to inject into the update-engine.service through a dropins;

        - name: "proxy.conf"
          contents: |
            [Service]
            Environment="ALL_PROXY=<REDACTED>"

Impact

Machines behind a proxy aren't updating anymore.

Environment and steps to reproduce

1. Set-up: A Machine that does not have access to the internet directly
2. Task: Let locksmith try to update to the latest stable version
3. Error: observe the following message;

E0119 17:56:40.732053  1189 payload_processor.cc:487] prefs->GetInt64(kPrefsUpdateStateNextOperation, &next_operation) && next_operation != kUpdateStateOperationInvalid && next_operation > 0 failed.
E0119 17:58:48.966884  1189 postinstall_runner_action.cc:94] Postinst command failed with code: 1
E0119 17:58:48.974634  1189 update_attempter.cc:615] Update failed.
E0119 17:58:49.812515  1189 omaha_request_action.cc:626] HTTP reported success but Omaha reports an error.

Expected behavior

Get an updated machine on latest version of flatcar.

Additional information

We've tried to understand what happened, and we believe it's due to some change of the curl library being removed and another fetcher being used in the flatcar-postinst script. The reason we believe so is that we were able to test the download which seems to be successful, but something fail after. We believe it might be linked to the following change ;
flatcar/update_engine@43bb354

We'll keep on posting if we ever find the issue for sure. Please let us know if you require anything else from us.