Interrupting `kathara exec` doesn't interrupt the command being exec'd

[Trigary]

Operating System

Ubuntu 24.04.3 LTS running on WSL2

Kathará Version

3.8.0

Bug Description

Interrupting (via Ctrl+C) kathara exec <device> <command> doesn't interrupt the <command> being executed. It continues running in the background.

Steps To Reproduce

On 192.168.1.2: run tcmpdump and observe the output.

In another terminal:

• Run kathara exec pc1 ping 192.168.1.2
• In the other terminal we can see the ICMP packets
• Interrupt the pinging by pressing Ctrl+C
• We receive back the prompt, the interruption was seemingly successful
• In the other terminal we can see that ICMP packets are still being received

Expected Behavior

When I press Ctrl+C while kathara exec pc1 ping 192.168.20.20 is running, I expect the pinging to stop.

Check Command Output

Current Manager is:             Docker (Kathara)
Manager version is:             28.5.1
Python version is:              3.12.3 (main, Aug 14 2025, 17:47:21) [GCC 13.3.0]
Kathara version is:             3.8.0
Operating System version is:    Linux-6.6.87.2-microsoft-standard-WSL2-x86_64
[Deploying devices]   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 1/1
[Deleting devices]   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 1/1
✓ Container run successfully.

[tcaiazzi]

Dear @Trigary,

Thanks for opening the issue!

You are right, we should interrupt the command when Ctrl+C is pressed.

We will consider this for the next release. If you’d like to contribute, PRs are always welcome!

Thanks.

[Skazza94]

Dear @Trigary,

I've investigated the issue and managed to reproduce it.

That said, the behavior is not related to Kathará itself but stems from Docker. There are several open issues in the official Docker repository reporting the same problem. The root cause is the lack of an official API to kill a process (see #9098).

While some workarounds exist, e.g., retrieving the PID via the stream API, the PID returned corresponds to the host process. This requires terminating the process from the host namespace, which is not cross-platform and does not work reliably on macOS and Windows, where Docker runs inside a VM or WSL.

As a result, we cannot address this issue on our side at the moment, since Docker itself does not provide a proper mechanism.

We will keep this issue open and implement a fix once the corresponding API is added and merged upstream in Docker.

[Trigary]

Thank you for looking into this issue! I didn't realize Docker doesn't support this.