https://wiki.archlinux.org/index.php/proxy_settings#Proxy_settings_on_GNOME3
Proxy settings on GNOME3
Some programs like Chromium prefer to use the settings stored by gnome. These settings can be modified through the gnome-control-center front end and also through gsettings.
gsettings set org.gnome.system.proxy mode 'manual' gsettings set org.gnome.system.proxy.http host 'proxy.localdomain.com' gsettings set org.gnome.system.proxy.http port 8080 gsettings set org.gnome.system.proxy.ftp host 'proxy.localdomain.com' gsettings set org.gnome.system.proxy.ftp port 8080 gsettings set org.gnome.system.proxy.https host 'proxy.localdomain.com' gsettings set org.gnome.system.proxy.https port 8080 gsettings set org.gnome.system.proxy ignore-hosts "['localhost', '127.0.0.0/8', '10.0.0.0/8', '192.168.0.0/16', '172.16.0.0/12' , '*.localdomain.com' ]"
google的chrome使用gnome设置的代理, export出来的环境变量http_proxy/https_proxy/no_proxy等不识别。