A Python library to run untrusted code in secure, isolated Docker based sandboxes. It is used to automatically grade programming assignments on Stepik.org.
It allows to spawn a process inside one-time Docker container, send data
to stdin, and obtain its exit code and stdout/stderr output. It's very similar
to what the subprocess
module does but additionally you can specify a custom environment for the process
(a Docker image)
and limit the CPU, memory, disk, and network usage for the running process.
Run a simple Python script in a one-time Docker container using the
python:3.6.5-alpine image:
import epicbox
epicbox.configure(
profiles=[
epicbox.Profile('python', 'python:3.6.5-alpine')
]
)
files = [{'name': 'main.py', 'content': b'print(42)'}]
limits = {'cputime': 1, 'memory': 64}
result = epicbox.run('python', 'python3 main.py', files=files, limits=limits)The result value is:
{'exit_code': 0,
'stdout': b'42\n',
'stderr': b'',
'duration': 0.143358,
'timeout': False,
'oom_killed': False}The available limit options and default values:
DEFAULT_LIMITS = {
# CPU time in seconds, None for unlimited
'cputime': 1,
# Real time in seconds, None for unlimited
'realtime': 5,
# Memory in megabytes, None for unlimited
'memory': 64,
# limit the max processes the sandbox can have
# -1 or None for unlimited(default)
'processes': -1,
}
A more advanced usage example of epicbox is to compile a C++ program and then
run it multiple times on different input data. In this example epicbox will
run containers on a dedicated Docker Swarm
cluster instead of locally installed Docker engine:
import epicbox
PROFILES = {
'gcc_compile': {
'docker_image': 'stepik/epicbox-gcc:6.3.0',
'user': 'root',
},
'gcc_run': {
'docker_image': 'stepik/epicbox-gcc:6.3.0',
# It's safer to run untrusted code as a non-root user (even in a container)
'user': 'sandbox',
'read_only': True,
'network_disabled': False,
},
}
epicbox.configure(profiles=PROFILES, docker_url='tcp:https://1.2.3.4:2375')
untrusted_code = b"""
// C++ program
#include <iostream>
int main() {
int a, b;
std::cin >> a >> b;
std::cout << a + b << std::endl;
}
"""
# A working directory allows to preserve files created in a one-time container
# and access them from another one. Internally it is a temporary Docker volume.
with epicbox.working_directory() as workdir:
epicbox.run('gcc_compile', 'g++ -pipe -O2 -static -o main main.cpp',
files=[{'name': 'main.cpp', 'content': untrusted_code}],
workdir=workdir)
epicbox.run('gcc_run', './main', stdin='2 2',
limits={'cputime': 1, 'memory': 64},
workdir=workdir)
# {'exit_code': 0, 'stdout': b'4\n', 'stderr': b'', 'duration': 0.095318, 'timeout': False, 'oom_killed': False}
epicbox.run('gcc_run', './main', stdin='14 5',
limits={'cputime': 1, 'memory': 64},
workdir=workdir)
# {'exit_code': 0, 'stdout': b'19\n', 'stderr': b'', 'duration': 0.10285, 'timeout': False, 'oom_killed': False}epicbox can be installed by running pip install epicbox. It's tested on Python 3.4+ and
Docker 1.12+.
You can also check the epicbox-images repository that contains Docker images used to automatically grade programming assignments on Stepik.org.
Contributions are welcome, and they are greatly appreciated! More details can be found in CONTRIBUTING.