There are applications which don't work over proxy. Last time I tried Software Center did not work. update-manager also has issues connecting to proxy though there is a workaround.
How do I find out where to change the proxy settings? As far as I know there are three ways to do it
- GNOME Proxy Settings
- Using
export http_proxyeither for that instance or putting it in bashrc file /etc/apt/apt.conffor APT applications
This is utterly confusing. I was helping a colleague in getting his update-manage to work over work proxy. I finally asked Michal Vogt and he reminded me that probably my colleague has not pressed "Apply system wide". I guess system-wide should be the default behaviour unless an app overrides it explicitly.
Next time if an app does not work over proxy, where should I look for? Is there a hint? This question is not only for me but also for many people whom I help. I cannot be sitting with them all the time. I need to tell them how to proceed.
Well I would say, if the application is tied closely to GNOME (or any of the libraries closely related to GNOME), then it will use GNOME proxy settings.
If it is something to do with the package management stuff, then it will search in apt.conf
And finally, if it is a CLI utility, the bash variables or a configuration file.
It's useful to check the app's documentation/manpage to know where does it look for the settings.