Slack Hook proxy configuration no longer supported by slack-ruby-client

[captainfalcon23]

• [X ] I have read and understood docs/Issues.md.

Describe the bug
We discovered that our slack hooks from Oxidized broke some time back in January, noting at that time [0.31.0 – 2024-11-29] change log shows:

Updated slackdiff.rb to use slack_ruby_client instead of slack-api (@Punicaa)
Updated slackdiff.rb to use new files.getUploadURLExternal slack file upload API instead of deprecated files.upload (@varesa)

As per the current documentation and old behaviour, the slack hook exposed a "proxy" configuration item. In our case, we must set an explicit proxy to reach slack. See https://github.com/ytti/oxidized/blob/master/docs/Hooks.md#hook-type-slackdiff:~:text=A%20proxy%20can%20optionally%20be%20specified%20if%20needed%20to%20reach%20the%20Slack%20API%20endpoint.

Noting also, after the slack upload method has changed, it takes 3 calls to upload a file to slack:

1. https://slack.com/api/files.getUploadURLExternal
2. https://files.slack.com/upload/v1
3. < finalize upload - didn't get to this part, don't have the specific URL handy >

What we identified is, when we set the proxy configuration to use a HTTPS proxy, we get an error like:

E, [2025-06-06T03:46:39.623018 #32] ERROR -- : Hook slack (#<SlackDiff:0x00007f8ef4b92c58>) failed (#<Faraday::SSLError wrapped=#<OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 peeraddr=10.255.254.1:8888 state=error: unexpected eof while reading>>) for event :post_store

This is likely because it is trying to talk HTTP to HTTPS proxy.

When we set the proxy configuration to use HTTP proxy, it completes the first step to slack.com, then gets stuck on files.slack.com - My guess here is because it's not using the proxy configuration and there's no outbound route to the internet in our case (hence explicit proxy is needed).

When we make an adjustment and expose and set "http_proxy" and "https_proxy" OS variables and DO NOT set the oxidized hook proxy, everything magically works!

This makes sense as per: https://github.com/slack-ruby/slack-ruby-client#:~:text=You%20can%20also%20control%20what%20proxy%20options%20are%20used%20by%20modifying%20the%20http_proxy%20environment%20variable%20per%20Net%3A%3AHTTP%27s%20documentation.

Expected behavior
The proxy setting in oxidized hook config should flow all the way through to the utilized gem.

Running environment (please complete the following information):
Latest version 0.33.0 on official docker image.

[robertcheramy]

When we make an adjustment and expose and set "http_proxy" and "https_proxy" OS variables and DO NOT set the oxidized hook proxy, everything magically works!

Can you share the the adjustment or - better - submit a PR?

@Punicaa or @varesa - can you help on this?

[varesa]

Looking at https://github.com/ytti/oxidized/blob/master/lib/oxidized/hook/slackdiff.rb#L14-L36 I can see that the first API request uses the "slack client" while the other two are done using plain Net::HTTP with no regard to the proxy configuration. EDIT: And that's my fault too 😄

So the fix, if we don't want to change the interface from config to env variables, would be to do something like https://ruby-doc.org/stdlib-2.4.3/libdoc/net/http/rdoc/Net/HTTP.html#class-Net::HTTP-label-Proxies to pass the proxy config onto the Net::HTTP (or see if the slack library now implements the other two methods too?)

I don't have easy access to a slack bot token for the moment, so it's not easy for me to test such a chance :-/

[captainfalcon23]

When we make an adjustment and expose and set "http_proxy" and "https_proxy" OS variables and DO NOT set the oxidized hook proxy, everything magically works!

Can you share the the adjustment or - better - submit a PR?

@Punicaa or @varesa - can you help on this?

The adjustment was setting the proxy as the OS level eg export http_proxy=my.proxy.com

I’m not a ruby dev so unfortunately I cannot help with a PR.

[varesa]

I'm not a Ruby dev either - or at least the slack API change was the first time I touched Ruby and this now being the second time.

In any case, an attempt to fix the issue: #3587

[robertcheramy]

Fixed by PR #3587 .
Thank you @varesa 👍