Question
When I try to install dependencies via pip inside a container (or do something else that initializes a new thread) the error RuntimeError: can't start new thread is thrown.
To reproduce:
from threading import Thread
def threaded_print(arg):
print(arg)
thread = Thread(target=threaded_print, args=("Hello World",))
thread.start()
Answer
The container is missing a security option. For a docker-compose setup you need to append the following:
security_opt:
- seccomp:/etc/docker/seccomp-systemd.json
If you use docker directly you can solve this via:
docker run --security-opt seccomp=/path/to/seccomp/profile.json <image>