http_proxy and https_proxy (and probably no_proxy) not supported out of the box

[HoneyryderChuck]

I don't know if this was by design, but it took me some figuring out on how to explicitly set proxy.

However, for portability, I'd automatically set proxy from the environment (the http{,s}_proxy env var), just like net/http does.

It's not that hard, as URI#find_proxy is all you need to accomplish this. This also has the benefit of supporting the no_proxy env var.

[britishtea]

While convenient, perhaps it's better to be explicit about this. See for example https://httpoxy.org.

[HoneyryderChuck]

It seems that this could be mitigated by the web server though, as most ruby deployments don't run as CGI (?). Still, this an available convenience from ruby standard library.

[HoneyryderChuck]

@britishtea see http://ruby-doc.org/stdlib-2.3.1/libdoc/uri/rdoc/URI/Generic.html#method-i-find_proxy it's already solved for ruby.

[brodock]

I would like to add some context here. Being able to set proxy based on environmental variables like the examples above, is critical when using code inside intranets or "big corps". There are many ways in which connecting to the outside world can be restricted in those environments and a proxy is a way to let whitelisted applications access the external world.

While I understand that a proxy can be a choice of the programmer when explicitly called by the chainable .via method, its also a choice of the system administrator, when defined by the env variables, and we shouldn't break this characteristic.

These three env variables are a default on Linux, and when set, are usually defined in /etc/environments, so its available system-wide, or on a per-application basis.

[tarcieri]

@brodock we're aware of the concept of egress proxies and the associated utility of this feature 😉

If you'd like to move this forward, I'd suggest opening a PR. It seems @HoneyryderChuck had this partially implemented at one point? HoneyryderChuck@4eeacc1

URI#find_proxy appears to do the heavy lifting already.