Using a proxy server for Slack integration

[nabeards]

I am trying to use a proxy server to connect to Slack, but it doesn't appear that MatterBridge ever sends a request to the configured proxy and instead just fails to connect with an error. Slack connects and works properly without the proxy server.

Working without proxy:

% ./matterbridge-1.26.0-darwin-arm64 --debug
[0000]  INFO main:         [setupLogger:matterbridge.go:104] Enabling debug logging.
[0000]  INFO main:         [main:matterbridge.go:44] Running version 1.26.0 6dafebc7
[0000]  INFO router:       [Start:gateway/router.go:66] Parsing gateway mygateway
[0000]  INFO router:       [Start:gateway/router.go:75] Starting bridge: slack.myslack 
[0000]  INFO slack:        [Connect:bridge/slack/slack.go:110] Connecting using token
[0000]  INFO slack:        [joinChannels:bridge/bridge.go:77] slack.myslack: joining bot-test (ID: bot-testslack.myslack)
[0000] DEBUG slack:        [handleSlack:bridge/slack/handlers.go:23] Choosing token based receiving
[0000] DEBUG slack:        [handleSlackClient:bridge/slack/handlers.go:53] == Receiving event &slack.ConnectingEvent{Attempt:1, ConnectionCount:0}
[0001] DEBUG slack:        [handleSlack:bridge/slack/handlers.go:27] Start listening for Slack messages
[0001]  INFO slack:        [joinChannels:bridge/bridge.go:77] slack.myslack: joining bot-test-2 (ID: bot-test-2slack.myslack)
[0001] DEBUG slack:        [populateChannels:bridge/slack/users_channels.go:273] Not refreshing channel list as it was done less than 10s seconds ago.
[0001]  INFO main:         [main:matterbridge.go:68] Gateway(s) started succesfully. Now relaying messages

With proxy configured:

% https_proxy=http://local.dev:3020 ./matterbridge-1.26.0-darwin-arm64 --debug
[0000]  INFO main:         [setupLogger:matterbridge.go:104] Enabling debug logging.
[0000]  INFO main:         [main:matterbridge.go:44] Running version 1.26.0 6dafebc7
[0000]  INFO router:       [Start:gateway/router.go:66] Parsing gateway mygateway
[0000]  INFO router:       [Start:gateway/router.go:75] Starting bridge: slack.myslack 
[0000]  INFO slack:        [Connect:bridge/slack/slack.go:110] Connecting using token
[0000]  INFO slack:        [joinChannels:bridge/bridge.go:77] slack.myslack: joining bot-test (ID: bot-testslack.myslack)
[0000] DEBUG slack:        [handleSlack:bridge/slack/handlers.go:23] Choosing token based receiving
[0000] DEBUG slack:        [handleSlackClient:bridge/slack/handlers.go:53] == Receiving event &slack.ConnectingEvent{Attempt:1, ConnectionCount:0}
[0000] DEBUG slack:        [handleSlackClient:bridge/slack/handlers.go:53] == Receiving event &slack.ConnectionErrorEvent{Attempt:1, Backoff:100000000, ErrorObj:(*url.Error)(0x14000248870)}
[0000] ERROR slack:        [handleSlackClient:bridge/slack/handlers.go:101] Connection failed "Post \"https://slack.com/api/rtm.connect\": unexpected EOF" &url.Error{Op:"Post", URL:"https://slack.com/api/rtm.connect", Err:(*errors.errorString)(0x1400010e070)}
[0000] ERROR slack:        [populateChannels:bridge/slack/users_channels.go:300] Could not retrieve channels: &url.Error{Op:"Post", URL:"https://slack.com/api/conversations.list", Err:(*errors.errorString)(0x1400010e070)}
[0000] FATAL main:         [main:matterbridge.go:66] Starting gateway failed: Bridge slack.myslack failed to join channel: could not join channel: &errors.errorString{s:"channel bot-test not found"}

local.dev is in my hosts file pointing to 127.0.0.1. Running the proxy server locally on port 3020, and I see no request coming in from MatterBridge. The failure is very quick.

I've also tried setting http_proxy, HTTP_PROXY, and HTTPS_PROXY, all with the same failure.
Does anyone have experience running MatterBridge through a proxy properly? TIA

[nabeards]

As a follow-up, I also have this in my settings for Slack:
SkipTLSVerify=true

[nabeards]

It definitely seems that SkipTLSVerify is ignored when using tokens with Slack.