The shell (/bin/sh) command executed once the proxy starts. When browser exits, the proxy exits. An extra env var PROXY is available.
Here, we use a separate Chrome instance in Incognito mode, so that it can run (and be waited for) alongside the default one, and that it maintains no state across runs. To configure this browser open a normal window in it, settings will be preserved.
@volth: chromium is to open a plain HTTP (not HTTPS nor redirect to HTTPS!) website. upstream uses http://example.com but I have seen captive portals whose DNS server resolves "example.com" to 127.0.0.1
Declarations
Type
stringDefault
env XDG_CONFIG_HOME="$PREV_CONFIG_HOME" ${pkgs.chromium}/bin/chromium --user-data-dir=${XDG_DATA_HOME:-$HOME/.local/share}/chromium-captive --proxy-server="socks5://$PROXY" --host-resolver-rules="MAP * ~NOTFOUND , EXCLUDE localhost" --no-first-run --new-window --incognito -no-default-browser-check http://cache.nixos.org/