Host-spawn: A better way to run host commands from inside your toolbox

Project Discussion
#1

In case it helps someone else, I’ve written an alternative implementation of flatpak-spawn --host that fixes a few of its shortcomings.

Example, spawning a shell:

toolbox$ flatpak-spawn --host sh
sh: cannot set terminal process group (-1): Inappropriate ioctl for device
sh: no job control in this shell
sh-5.1$ exit

toolbox$ host-spawn sh
sh-5.1$ exit

Example, running sudo:

toolbox$ flatpak-spawn --host sudo id
sudo: a terminal is required to read the password; either use the -S option to read from standard input or configure an askpass helper
^C^Csudo: a password is required

toolbox$ host-spawn sudo id
[sudo] password for sph:
uid=0(root) gid=0(root) groups=0(root) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

Also it’s got a neat feature that if you symlink it, it’ll always run a command on the host:

toolbox$ ls -l /usr/local/bin/rpm-ostree
lrwxrwxrwx 1 root root 25 Jul 24 11:40 /usr/local/bin/rpm-ostree -> /usr/local/bin/host-spawn

toolbox$ rpm-ostree status
State: idle
[...]
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#2

Very nice! Gave this a spin and works great so far. Was just looking at the flatpak-spawn limitations yesterday. :slight_smile:

Have you discussed with upstream about enhancing flatpak-spawn directly?

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#3

Yes, I’ve talked about this project existence on the relevant upstream issues.

The reason why it’s a reimplementation is because it was faster for me to explore the problem space in Go than learning GLib to hack on flatpak-spawn. But I’ve licensed host-spawn with a non-attribution license so that anyone is free to backport its logic upstream.

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#4

This is great!

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#5

Maybe we can get this into toolbx by default as it’s all Go code?

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#6

I use it with distrobox, so I’m open for it to be distributed with toolbx as long as it doesn’t mean moving the entire repository under toolbox.

1 Like