host-spawn

A reimplementation of flatpak-spawn --host.

Run commands on your host machine from inside your flatpak sandbox, toolbox or distrobox containers.

Improvements over the original

• Allocates a pty for the spawned process, fixing the following upstream issues: flatpak/flatpak#3697, flatpak/flatpak#3285 and flatpak/flatpak-xdg-utils#57
• Handles SIGWINCH (terminal size changes)
• Passes through $TERM environment variable
• Shims host binaries when symlinked, see section below

Creating shims for host binaries

If there's a process that only makes sense to be executed on the host system, you can create a symlink to it somewhere in your $PATH and it'll always be executed through host-spawn.

Example of creating a shim for the flatpak command:

# Inside your container

$ flatpak --version
zsh: command not found: flatpak
$ ln -s /usr/local/bin/host-spawn /usr/local/bin/flatpak
# Now the flatpak command will always be executed on the host
$ flatpak --version
Flatpak 1.12.7

References

• https://github.com/owtaylor/PurpleEgg/blob/master/common/host-command.c
• https://github.com/gnunn1/tilix/blob/master/source/gx/tilix/terminal/terminal.d