:help i_CTRL-H

 or CTRL-H  Delete the character before the cursor (see i_backspacing                                                       about joining lines).

From a security point of view, it’s better to create a dedicated network for each of your containers, as apps won’t be able to communicate with each others directly.

You can even not setup networking at all and use UNIX sockets instead. However, back-end apps will need to support that.

What about DroidFS?