Wrong owner in /dev/pts

[Gavus]

Describe the bug
My /dev/pts/ inside a toolbox have the owner set as root. Outside of toolbox they are owned by my user.

Steps how to reproduce the behaviour

1. Enter a running toolbox with at least two sessions.
2. Start python3.
3. Enter: "import io; tty=io.TextIOWrapper(open("/dev/pts/x", "r+b", buffering=0))" (replace x with one of the session numbers).

Expected behaviour
No error.

Actual behaviour
"PermissionError: [Errno 13] Permission denied: '/dev/pts/x'.

Output of toolbox --version (v0.0.90+)
toolbox version 0.0.99.3

Toolbox package info (Github)
tag 0.0.99.3

Output of podman version
e.g.,

Version:            3.0.1
RemoteAPI Version: ?
Go Version:         ?
OS/Arch:            linux/amd64
``

**Info about your OS**
Debian 11 (bullseye)

**Additional context**
I noticed this problem when using the python debugger module pudb, wanting to display the tui in another terminal.

[Ramblurr]

This also prevents the use of emacsclient --tty:

$ emacsclient --tty
*ERROR*: Could not open file: /dev/pts/1
$ sudo chown ramblurr /dev/pts/1
$ emacsclient --tty
<emacs opens>

For my system:

toolbox --version
toolbox version 0.0.99.3

podman version
Client:       Podman Engine
Version:      4.3.1
API Version:  4.3.1
Go Version:   go1.19.2
Built:        Fri Nov 11 16:01:27 2022
OS/Arch:      linux/amd64

• OS: Fedora Silverblue 37
• podman package: podman-4.3.1-1.fc37.x86_64
• toolbox package: toolbox-0.0.99.3-7.fc37.x86_64

[swick]

This also prevents the mutter kvm test suit from running:

qemu-system-x86_64: -chardev file,id=console,path=/proc/self/fd/2

@debarshiray

[debarshiray]

I filed containers/crun#1158 for some clarifications and advice.

[debarshiray]

I filed containers/podman#17701 for some clarifications and advice.

That got renamed to containers/crun#1158

[debarshiray]

The original problem reported with Python does appear to be solved by PR containers/crun#1159 that's linked from the above podman/crun issue:

⬢[rishi@toolbox ~]$ tty
/dev/pts/0
⬢[rishi@toolbox ~]$ 
⬢[rishi@toolbox ~]$ ls -l /dev/pts
total 0
crw--w----. 1 rishi tty  136, 0 Mar  8 21:21 0
crw-rw-rw-. 1 root  root   5, 2 Mar  8 21:07 ptmx
⬢[rishi@toolbox ~]$ 
⬢[rishi@toolbox ~]$ python3
Python 3.10.8 (main, Nov 14 2022, 00:00:00) [GCC 12.2.1 20220819 (Red Hat 12.2.1-2)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import io; tty=io.TextIOWrapper(open("/dev/pts/0", "r+b", buffering=0))
>>> 

[debarshiray]

This also prevents the use of emacsclient --tty:

$ emacsclient --tty
*ERROR*: Could not open file: /dev/pts/1
$ sudo chown ramblurr /dev/pts/1
$ emacsclient --tty
<emacs opens>

I suspect that this is similar to the problem @dustymabe has been facing with gpg-agent and pinentry in #568

Even if you fix the user ownership of the pseudo-terminal device (ie., the output of tty(1)), running emacsclient --tty inside the container doesn't open Emacs in the same terminal. Instead it opens it on a different host terminal whose tty(1) accidentally happens to match the container's.

I use Emacs, but not in a server-client mode, so I am not entirely sure, but I think that the client should open in the same terminal where I typed emacsclient --tty. At least that's what happens on the host.

It's an accident because the pseudo-terminal devices inside the container aren't the same as on the host. They are totally different because the container has it's own devpts file system at /dev/pts within its mount and user namespaces.

[debarshiray]

This also prevents the mutter kvm test suit from running:

qemu-system-x86_64: -chardev file,id=console,path=/proc/self/fd/2

Does containers/crun#1159 help?

I can try to run the mutter test suite myself, but it will take some time. :)