Socket mode and proxy not working

[franco-martin]

(Filling out the following details about bugs will help us solve your issue sooner.)

Reproducible in:

The Slack SDK version

slack-bolt==1.3.0
slack-sdk==3.3.0
slackclient==2.9.3
slackeventsapi==2.2.1

Python runtime version

Python 3.8.6

OS info

Windows 10
Microsoft Windows [Version 10.0.19041.746]

Steps to reproduce:

client = WebClient(token=config.SLACK_BOT_TOKEN,
                   proxy="http://myproxy:8080"
                   )
app = App(client=client)

Expected result:

Application working

Actual result:

DEBUG:slack_sdk.web.base_client:Sending a request - url: https://www.slack.com/api/auth.test, query_params: {}, body_params: {}, files: {}, json_body: {}, headers: {'Content-Type': 'application/json;charset=utf-8', 'Authorization': '(redacted)', 'User-Agent': 'Python/3.8.6 slackclient/3.3.0 Windows/10'}
DEBUG:slack_sdk.web.slack_response:Received the following response - status: 200, headers: {...}, body: {'ok': True, 'url': 'https://....com/', 'team': '...', 'user': '...', 'team_id': '...', 'user_id': '...', 'bot_id': '...', 'is_enterprise_install': False}
DEBUG:slack_sdk.web.base_client:Sending a request - url: https://www.slack.com/api/apps.connections.open, query_params: {}, body_params: {}, files: {}, json_body: None, headers: {}
DEBUG:slack_sdk.web.slack_response:Received the following response - status: 200, headers: ..., body: {'ok': True, 'url': 'wss://wss-primary.slack.com/link/?ticket=...}
INFO:slack_bolt.App:Using non-ssl socket to connect (MYPROXY:8080)
WARNING:slack_bolt.App:Received an unexpected response for handshake (status: 400, response: HTTP/1.1 400 Bad Request
Cache-Control: no-cache
Pragma: no-cache
Content-Type: text/html; charset=utf-8
Proxy-Connection: close
Connection: close
Content-Length: 716, session id: ...)

I checked the proxy logs and got the following:

GET <invalid request url>

failed because: Scheme was not delimited by '://'

[stevengill]

Hey @franco-martin,

I believe this is a duplicate of #948. We have an open PR for this in #951

[franco-martin]

hey @stevengill thank your for the quick response, I dont think so. That user is getting timeouts and the issue is because its ignoring the HTTP proxy. Im using an HTTPS proxy and getting bad request errors. My app is connecting but sending incorrect data. Does that make sense?
This is why im suspicious of the following

 INFO:slack_bolt.App:Using non-ssl socket to connect (MYPROXY:8080)

I think It should be using an ssl socket

[seratch]

@franco-martin Although the error you're facing is a bit different from the one in that issue, the pull request should resolve this issue. The current implementation is just incomplete.