Support downloading the language server through proxy settings

[teucer]

Environment data

• VS Code version: 1.26.0
• Extension version (available under the Extensions sidebar): 2018.7.1
• OS and version: windows 7
• Python version (& distribution if applicable, e.g. Anaconda): 3.6.6 (miniconda)
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): conda
• Relevant/affected Python packages and their versions: XXX

Actual behavior

Language server and linting does not work

Expected behavior

Language server and linting should work

Steps to reproduce:

Behind company proxy (I believe this is causing the issue)

Logs

Starting Microsoft Python language server.
Downloading https://pvsc.blob.core.windows.net/python-language-server/Python-Language-Server-win-x64.0.1.18204.3.nupkg... failed.
Error: tunneling socket could not be established, cause=write EPROTO 101057795:error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:d:\buildagent\workspace\318698\vendor\node\deps\openssl\openssl\ssl\s23_clnt.c:827:

[brettcannon]

Do you need a way to set proxy settings to make this work? I would assume we are already using the proxy settings of your OS so it's a question of whether being able to set more specific settings would have somehow alleviated this failure.

[DonJayamanne]

I would assume we are already using the proxy settings of your OS

Unfortunately no.

Solution: All we need to do is get the proxy from the config as follows:

proxy = workspace.getConfiguration('http').get('proxy', '');
And pass that into the request.
I missed this when reviewing the code, I've used this in the past in other extensions :(

Note, VSC have an issue that would automate this process for us.
Support downloading of additional resources when installing an extension

[DonJayamanne]

@brettcannon
Changed to P0 and added to current milestone, as this has the potential to affect a number of other users.
At a minimum it'll be P0 before we switch to the language server.
Please feel free to change the labels.

[brettcannon]

Yes, it's a P0 for September, but it's a P1 for August.

[brettcannon]

Flagging this as a good first issue since Don basically said what to do. 😁

[d3r3kk]

I've picked up this task, and after reading into the issue a bit I see this information on the subject here:
https://code.visualstudio.com/docs/setup/network

Proxy support for extensions being what it is today, plus @DonJayamanne's suggestion above, means that we will support the proxy but not any further authentication. Instead, we will wait for VSCode support for downloading extra assets during extension installation via microsoft/vscode#53855.