A Terminator plugin that runs the source ~/.bashrc command on all open terminals of the active window.
It adds a menu item and also a keyboard shortcut that is currently hardcoded to Alt+S.
To install it, simply copy the multisource.py file to ~/.config/terminator/plugins and then enable it through the preferences menu. If you don't have a plugins directory under terminator, create one first!
Tested with Ubuntu 14.04, Ubuntu 16.04, Ubuntu 18.04 and MX Linux 18.1.