Run Chrome/Chromium with proxy settings on Linux

If you open the "Proxy Settings" window on Chrome and Chromium for Linux, a discouraging message shows up:

When running Chromium under a supported desktop environment, the system proxy settings will be used. However, either your system is not supported or there was a problem launching your system configuration.

But you can still configure via the command line. Please see man chromium for more information on flags and environment variables.

Fair enough: Chrome and Chromium cannot read environment parameters I set up for my proxy, so the solution lies in the command line. What follows is the generic option flag for when you invoke Chrome/Chromium from the terminal:

--proxy-server=<scheme>=<uri>[:<port>][;...] | <uri>[:<port>] | "direct://"

This tells Chrome/Chromium to use a custom proxy configuration. You can specify a custom proxy configuration in several ways. The most common one is providing a semi-colon-separated mapping of list scheme to url/port pairs. For example:

--proxy-server="http=minimal.proxy:80;https=super.proxy:3128"

Of course you want to bypass proxy for when you connect to localhost. Here comes another parameter (generic version):

--proxy-bypass-list=(<trailing_domain>|<ip-address>)[:<port>][;...]

This tells Chrome/Chromium to bypass any specified proxy for the given semi-colon-separated list of hosts. This flag works only if the previously seen --proxy-server option is set, of course. Example:

--proxy-bypass-list="192.168.56.100:8080;127.0.0.1:8080;*.google.com"

As you can see, wildcards are supported as well.

Sources

Chromium.org - Network Settings (link)