Merge remote-tracking branch 'origin/master'

.gitlab-ci.yml

@@ -54,6 +54,24 @@ build_backend-staticfiles:
     DOCKERFILE_PATH: "Dockerfile.staticfiles"
     IMAGE_NAME: "$CI_REGISTRY_IMAGE/backend-staticfiles"
 
+build_checker:
+  <<: *build-template
+  rules:
+    - if: '$CI_COMMIT_REF_NAME == "master"'
+  variables:
+    CONTEXT: "${CI_PROJECT_DIR}/services/checker"
+    DOCKERFILE_PATH: "Dockerfile"
+    IMAGE_NAME: "$CI_REGISTRY_IMAGE/checker"
+
+build_custom-python:
+  <<: *build-template
+  rules:
+    - if: '$CI_COMMIT_REF_NAME == "master"'
+  variables:
+    CONTEXT: "${CI_PROJECT_DIR}/services/checker"
+    DOCKERFILE_PATH: "Dockerfile.checker"
+    IMAGE_NAME: "$CI_REGISTRY_IMAGE/custom-python"
+
 build_docs:
   <<: *build-template
   rules:

compose.yaml

@@ -370,6 +370,23 @@ services:
     restart: unless-stopped
     shm_size: 4mb
 
+  checker:
+    image: gitlab.prodcontest.ru:5050/team-15/project/checker:latest
+    build:
+      context: ./services/checker
+      dockerfile: Dockerfile
+    restart: unless-stopped
+    ports:
+      - name: web
+        target: 8000
+        published: 8009
+        host_ip: 0.0.0.0
+        protocol: tcp
+    volumes:
+      - type: bind
+        source: /var/run/docker.sock
+        target: /var/run/docker.sock
+
   proxy:
     image: docker.io/nginx:1.27-alpine3.21
     configs:

infrastructure/backend/.env.template

@@ -18,3 +18,5 @@ MINIO_ENDPOINT=minio:9000
 MINIO_CUSTOM_ENDPOINT_URL=https://prod-team-15-minio-2pc0i3lc.final.prodcontest.ru
 MINIO_ACCESS_KEY=admin
 MINIO_SECRET_KEY=password
+
+CHECKER_API_ENDPOINT=http://checker:8000

services/backend/Dockerfile.staticfiles

@@ -24,4 +24,6 @@ FROM docker.io/nginx:latest
 
 COPY --from=builder /app/static /usr/share/nginx/html
 
+COPY ../checker/checker_requirements.txt .
+
 CMD ["nginx", "-g", "daemon off;"]

services/backend/api/v1/task/views.py

@@ -155,5 +155,5 @@ def get_submissions_history(request, competition_id: UUID, task_id: UUID):
 def get_task_attachments(request, competition_id: UUID, task_id: UUID):
     task = get_object_or_404(CompetitionTask, id=task_id)
     return status.OK, CompetitionTaskAttachment.objects.filter(
-        competition_id=competition_id, task=task, user=request.auth
+        task=task
-    )
+    ).all()

services/backend/apps/task/tasks.py

@@ -1,155 +1,50 @@
-import ast
+import requests
-import contextlib
+from celery import shared_task
-import hashlib
+from django.core.files.base import ContentFile
-import os
-import sys
-import tempfile
-from io import StringIO
 
-from apps.task.models import CompetitionTaskSubmission
+from django.conf import settings
-from config.celery import app
-
-ALLOWED_MODULES = {
-    "pandas",
-    "numpy",
-    "matplotlib",
-    "seaborn",
-    "scipy",
-    "sklearn",
-    "datetime",
-    "json",
-    "csv",
-    "math",
-    "statistics",
-    "statsmodels",
-}
 
 
-class SecurityException(Exception):
+@shared_task(bind=True, max_retries=3)
-    pass
+def analyze_data_task(self, submission_id):
+    from .models import CompetitionTaskSubmission
 
-
+    submission = CompetitionTaskSubmission.objects.get(id=submission_id)
-def validate_code(code_str):
     try:
-        tree = ast.parse(code_str)
+        code = submission.content.read().decode()
-    except SyntaxError as e:
+        files = [
-        raise SecurityException(f"Syntax error: {e!s}")
+            (f.name, f.file.open("rb"))
+            for f in submission.task.attachments.filter(public=True)
+        ]
 
-    class ImportVisitor(ast.NodeVisitor):
+        response = requests.post(
-        def visit_Import(self, node):
+            f"{settings.CHECKER_API_ENDPOINT}/execute",
-            for alias in node.names:
+            files=[("files", (f.name, f)) for f in files]
-                module = alias.name.split(".")[0]
+            + [
-                if module not in ALLOWED_MODULES:
+                ("code", code),
-                    raise SecurityException(f"Disallowed import: {module}")
+                ("expected_hash", submission.task.correct_answer_hash),
+            ],
+            timeout=30,
+        )
+        response.raise_for_status()
+        result = response.json()
 
-        def visit_ImportFrom(self, node):
+        submission.stdout.save("output.txt", ContentFile(result["output"]))
-            if node.module:
+        submission.result = {
-                module = node.module.split(".")[0]
+            "correct": result["hash_match"],
-                if module not in ALLOWED_MODULES:
+            "result_hash": result["result_hash"],
-                    raise SecurityException(
+            "error": result.get("error"),
-                        f"Disallowed import from: {module}"
-                    )
-
-    class SecurityVisitor(ast.NodeVisitor):
-        def generic_visit(self, node):
-            if isinstance(node, (ast.Call, ast.Attribute)):
-                if "system" in getattr(node, "attr", ""):
-                    raise SecurityException("Dangerous system call detected")
-            super().generic_visit(node)
-
-    try:
-        ImportVisitor().visit(tree)
-        SecurityVisitor().visit(tree)
-    except SecurityException:
-        raise
-    except Exception as e:
-        raise SecurityException(f"Security check failed: {e!s}")
-
-
-def secure_exec(code_str, result_path, input_files=None):
-    original_dir = os.getcwd()
-    original_stdout = sys.stdout
-    sys.stdout = captured_stdout = StringIO()
-    result_content = None
-
-    if input_files is None:
-        input_files = []
-
-    with tempfile.TemporaryDirectory() as temp_dir:
-        try:
-            os.chdir(temp_dir)
-
-            for file in input_files:
-                file_path = os.path.join(temp_dir, file["bind_at"])
-                os.makedirs(os.path.dirname(file_path), exist_ok=True)
-                with open(file_path, "wb") as f:
-                    f.write(file["content"])
-
-            restricted_globals = {
-                "__builtins__": {
-                    "open": open,
-                    "print": print,
-                    "str": str,
-                    "int": int,
-                    "float": float,
-                    "bool": bool,
-                    "list": list,
-                    "dict": dict,
-                    "tuple": tuple,
-                    "set": set,
-                }
-            }
-
-            exec(code_str, restricted_globals)
-
-            if result_path == "stdout":
-                result_content = captured_stdout.getvalue().encode("utf-8")
-            else:
-                with open(result_path, "rb") as f:
-                    result_content = f.read()
-
-        except Exception as e:
-            raise RuntimeError(f"Execution error: {e!s}")
-        finally:
-            os.chdir(original_dir)
-            sys.stdout = original_stdout
-
-    return result_content
-
-
-@app.task(bind=True)
-def analyze_data_task(
-    self,
-    code_str,
-    result_path,
-    expected_file_link,
-    submission_id,
-    input_files=[],
-):
-    try:
-        validate_code(code_str)
-
-        result_content = secure_exec(code_str, result_path, input_files)
-
-        result_hash = hashlib.sha256(result_content).hexdigest()
-        expected_hash = hashlib.sha256(expected_bytes).hexdigest()
-
-        with contextlib.suppress(CompetitionTaskSubmission.DoesNotExist):
-            submission = CompetitionTaskSubmission.objects.get(
-                id=submission_id
-            )
-            submission.result = {"correct": True}
-
-        return {
-            "success": True,
-            "match": result_hash == expected_hash,
-            "result_hash": result_hash,
-            "expected_hash": expected_hash,
         }
+        submission.earned_points = (
+            submission.task.points if result["hash_match"] else 0
+        )
+        submission.status = CompetitionTaskSubmission.StatusChoices.CHECKED
 
-    except SecurityException as e:
+    except requests.exceptions.RequestException as e:
-        return {"success": False, "error": f"Security violation: {e!s}"}
+        self.retry(countdown=2**self.request.retries)
-    except RuntimeError as e:
-        return {"success": False, "error": f"Execution error: {e!s}"}
     except Exception as e:
-        return {"success": False, "error": f"Unexpected error: {e!s}"}
+        submission.result = {"error": str(e)}
+        submission.status = CompetitionTaskSubmission.StatusChoices.CHECKED
+        submission.earned_points = 0
+    finally:
+        submission.save()

services/backend/config/settings.py

@@ -7,7 +7,9 @@ from pathlib import Path
 
 import django_stubs_ext
 import environ
+from health_check.plugins import plugin_dir
 from django.utils.translation import gettext_lazy as _
+from integrations.checker.healthcheck import CheckerHealthCheck
 
 BASE_DIR = Path(__file__).resolve().parent.parent
 
@@ -30,18 +32,12 @@ ALLOWED_HOSTS = env(
 
 # Integrations
 
-YANDEX_CLOUD_FOLDER_ID = env("YANDEX_CLOUD_FOLDER_ID", default=None)
+CHECKER_API_ENDPOINT = env("CHECKER_API_ENDPOINT", default=None)
-
-YANDEX_CLOUD_API_KEY = env("YANDEX_CLOUD_API_KEY", default=None)
-
-YANDEX_CLOUD_INTEGRATION_ENABLED = (
-    YANDEX_CLOUD_FOLDER_ID and YANDEX_CLOUD_API_KEY
-)
 
 
 # Register healthchecks
 
-# plugin_dir.register(SomeHealthCheckClass)
+plugin_dir.register(CheckerHealthCheck)
 
 
 # Caching

services/backend/integrations/checker/healthcheck.py

@@ -0,0 +1,22 @@
+from http import HTTPStatus as status
+
+import httpx
+from django.conf import settings
+from health_check.backends import BaseHealthCheckBackend
+
+
+class CheckerHealthCheck(BaseHealthCheckBackend):
+    critical_service = False
+
+    def check_status(self) -> None:
+        try:
+            response = httpx.get(
+                f"{settings.CHECKER_API_ENDPOINT}/ping", timeout=1
+            )
+            if response.status_code >= status.INTERNAL_SERVER_ERROR:
+                self.add_error("Checker service is unaccessible")
+        except httpx.HTTPError:
+            self.add_error("Checker service is unaccessible")
+
+    def identifier(self) -> str:
+        return self.__class__.__name__

services/checker/.gitignore

@@ -0,0 +1,170 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+.python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+Pipfile.lock
+
+# UV
+#   Similar to Pipfile.lock, it is generally recommended to include uv.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+uv.lock
+
+# poetry
+#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
+poetry.lock
+
+# pdm
+#   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
+#pdm.lock
+#   pdm stores project-wide configurations in .pdm.toml, but it is recommended to not include it
+#   in version control.
+#   https://pdm.fming.dev/latest/usage/project/#working-with-version-control
+.pdm.toml
+.pdm-python
+.pdm-build/
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# PyCharm
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+.idea/
+
+# PyPI configuration file
+.pypirc
+
+# Ruff files
+.ruff_cache

services/checker/Dockerfile

@@ -0,0 +1,42 @@
+# Stage 1: Install dependencies
+FROM docker.io/python:3.11-alpine3.20 AS builder
+
+COPY --from=ghcr.io/astral-sh/uv:0.4.30 /uv /uvx /bin/
+
+WORKDIR /app
+
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    PYTHONOPTIMIZE=2 \
+    UV_COMPILE_BYTECODE=1 \
+    UV_PROJECT_ENVIRONMENT=/opt/venv
+
+COPY pyproject.toml .
+
+RUN uv sync --no-dev --no-install-project --no-cache
+
+
+# Stage 2: Start the application
+FROM docker.io/python:3.11-alpine3.20
+
+WORKDIR /app
+
+COPY --from=builder /opt/venv /opt/venv
+
+COPY . .
+
+RUN adduser -D -g '' app && chown -R app:app ./
+
+USER app
+
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    PYTHONOPTIMIZE=2 \
+    PATH="/opt/venv/bin:$PATH"
+
+EXPOSE 8080
+
+HEALTHCHECK --interval=30s --timeout=5s --start-period=5s --start-interval=2s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://127.0.0.1:8000/ping || exit 1
+
+CMD uvicorn main:app --host 0.0.0.0 --port 8000

services/checker/Dockerfile.checker

@@ -0,0 +1,14 @@
+FROM docker.io/python:3.11-slim
+
+ENV PYTHONUNBUFFERED=1 \
+    PIP_NO_CACHE_DIR=1
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    build-essential \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY checker_requirements.txt .
+
+RUN pip install --no-cache-dir -r checker_requirements.txt
+
+CMD ["python"]

services/checker/README.md

@@ -0,0 +1,87 @@
+# DataRush Checker
+
+## Prerequisites
+
+Ensure you have the following installed on your system:
+
+- [Python](https://www.python.org/) (>=3.10,<3.12)
+- [uv](https://docs.astral.sh/uv/)
+- [Docker](https://www.docker.com/) (for containerized setup)
+
+## Basic setup
+
+### Installation
+
+#### Clone the project
+
+```bash
+git clone git@gitlab.prodcontest.ru:team-15/project.git
+```
+
+#### Go to the project directory
+
+```bash
+cd project/services/checker
+```
+
+#### Install dependencies
+
+##### For dev environment
+
+```bash
+uv sync --all-extras
+```
+
+##### For prod environment
+
+```bash
+uv sync --no-dev
+```
+
+#### Running
+
+##### Apply migrations
+
+```bash
+uv run python manage.py migrate
+```
+
+##### Start celery worker
+
+```bash
+celery -A config worker -l INFO
+```
+
+##### Start server
+
+In dev mode:
+
+```bash
+uv run python manage.py runserver
+```
+
+In prod mode:
+
+```bash
+uv run gunicorn config.wsgi
+```
+
+## Containerized setup
+
+### Clone the project
+
+```bash
+git clone git@gitlab.prodcontest.ru:team-15/project.git
+```
+
+### Go to the project directory
+
+```bash
+cd project/services/checker
+```
+
+### Build docker image
+
+```bash
+docker build -t datarush-checker .
+```

services/checker/checker_requirements.txt

@@ -0,0 +1,7 @@
+pandas==2.2.3
+numpy==2.2.3
+matplotlib==3.10.1
+scipy==1.15.2
+scikit-learn==1.6.1
+seaborn==0.13.2
+statsmodels==0.14.4

services/checker/main.py

@@ -0,0 +1,289 @@
+from fastapi import FastAPI, HTTPException, status
+from pydantic import BaseModel, Field, HttpUrl, constr
+import aiohttp
+import asyncio
+import docker
+import hashlib
+import os
+import base64
+import tempfile
+import logging
+from urllib.parse import urlparse
+import re
+
+app = FastAPI()
+docker_client = docker.from_env()
+logger = logging.getLogger(__name__)
+logging.basicConfig(level=logging.INFO)
+
+
+DOCKER_IMAGE = "gitlab.python:3-slim"
+CONTAINER_TIMEOUT = 60
+MAX_FILE_SIZE = 4 * 1024 * 1024
+ALLOWED_FILENAME_CHARS = r"[^a-zA-Z0-9_\-.]"
+
+
+class FileDetails(BaseModel):
+    url: HttpUrl = Field(
+        ..., description="URL to download the file from (supports HTTP/HTTPS)"
+    )
+    bind_path: str = Field(
+        ...,
+        description="Container path to bind the file (absolute)",
+    )
+
+
+class ExecutionRequest(BaseModel):
+    code: str = Field(..., description="Base64 encoded Python code to execute")
+    answer_file_path: str = Field(
+        "stdout", description="Base64 encoded path to result file or 'stdout'"
+    )
+    expected_hash: str | None = Field(
+        None, description="Optional SHA-256 hash of expected output"
+    )
+    files: list[FileDetails] = Field(
+        [], description="List of files to mount in container"
+    )
+
+
+class ExecutionResponse(BaseModel):
+    success: bool = Field(..., description="Execution success status")
+    hash_match: bool | None = Field(
+        None, description="Output hash matches expected (if provided)"
+    )
+    output: str = Field(..., description="Captured stdout or file contents")
+    result_hash: str = Field(..., description="SHA-256 hash of output")
+    error: str = Field(..., description="Execution errors or stderr")
+
+
+class HealthCheckResponse(BaseModel):
+    status: str = Field(..., description="Service health status")
+    docker: str = Field(..., description="Docker daemon status")
+
+
+def decode_base64(encoded_str: str, field_name: str) -> str:
+    try:
+        return base64.b64decode(encoded_str).decode("utf-8")
+    except Exception as e:
+        logger.error(f"Base64 decode failed for {field_name}: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"Invalid Base64 in {field_name}",
+        )
+
+
+def sanitize_filename(url: str) -> str:
+    parsed = urlparse(url)
+    base_name = os.path.basename(parsed.path)
+
+    if not base_name:
+        base_name = "file"
+
+    clean = re.sub(ALLOWED_FILENAME_CHARS, "", base_name)[:255]
+    return clean or "file"
+
+
+async def download_file(
+    session: aiohttp.ClientSession, url: str, dest_path: str
+) -> None:
+    try:
+        async with session.get(
+            url, timeout=aiohttp.ClientTimeout(total=30)
+        ) as resp:
+            if resp.status != 200:
+                raise HTTPException(
+                    status_code=status.HTTP_400_BAD_REQUEST,
+                    detail=f"Failed to download {url} - Status {resp.status}",
+                )
+
+            content = b""
+            async for chunk in resp.content.iter_chunked(8192):
+                content += chunk
+                if len(content) > MAX_FILE_SIZE:
+                    raise HTTPException(
+                        status_code=status.HTTP_413_REQUEST_ENTITY_TOO_LARGE,
+                        detail="File size exceeds 4MB limit",
+                    )
+
+            with open(dest_path, "wb") as f:
+                f.write(content)
+            logger.info(f"Downloaded {url} to {dest_path}")
+
+    except aiohttp.ClientError as e:
+        logger.error(f"Download error for {url}: {str(e)}")
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"Download failed: {str(e)}",
+        )
+
+
+def run_container_safely(
+    tmp_dir: str,
+    command: list[str],
+    bound_files: dict[str, str],
+    timeout: int = CONTAINER_TIMEOUT,
+) -> dict:
+    container = None
+    try:
+        volumes = {tmp_dir: {"bind": "/execution", "mode": "rw"}}
+        for host_path, container_path in bound_files.items():
+            volumes[host_path] = {"bind": container_path, "mode": "ro"}
+
+        container = docker_client.containers.run(
+            image=DOCKER_IMAGE,
+            command=command,
+            volumes=volumes,
+            working_dir="/execution",
+            stdout=True,
+            stderr=True,
+            detach=True,
+            mem_limit="100m",
+            network_mode="none",
+            cpu_period=100000,
+            cpu_quota=50000,
+            user="root",
+            security_opt=["no-new-privileges"],
+        )
+
+        exit_code = container.wait(timeout=timeout)["StatusCode"]
+        stdout = container.logs(stdout=True, stderr=False).decode().strip()
+        stderr = container.logs(stdout=False, stderr=True).decode().strip()
+
+        return {"stdout": stdout, "stderr": stderr, "status": exit_code}
+
+    except docker.errors.DockerException as e:
+        logger.error(f"Docker error: {str(e)}")
+        return {
+            "stdout": "",
+            "stderr": f"Container error: {str(e)}",
+            "status": -1,
+        }
+    finally:
+        if container:
+            try:
+                container.remove(force=True)
+            except docker.errors.DockerException:
+                pass
+
+
+@app.post("/execute", response_model=ExecutionResponse)
+async def execute_code(request: ExecutionRequest) -> ExecutionResponse:
+    try:
+        code = decode_base64(request.code, "code")
+        answer_path = (
+            decode_base64(request.answer_file_path, "answer_file_path")
+            if request.answer_file_path != "stdout"
+            else "stdout"
+        )
+    except HTTPException as e:
+        return ExecutionResponse(
+            success=False,
+            output="",
+            result_hash="",
+            error=e.detail,
+            hash_match=None,
+        )
+
+    if answer_path != "stdout":
+        if os.path.isabs(answer_path) or not validate_file_path(answer_path):
+            return ExecutionResponse(
+                success=False,
+                output="",
+                result_hash="",
+                error="Invalid answer file path",
+                hash_match=None,
+            )
+
+    with tempfile.TemporaryDirectory() as tmp_dir:
+        bound_files = {}
+        if request.files:
+            async with aiohttp.ClientSession() as session:
+                download_tasks = []
+                for file in request.files:
+                    filename = sanitize_filename(str(file.url))
+                    dest_path = os.path.join(tmp_dir, filename)
+                    bound_files[dest_path] = file.bind_path
+                    download_tasks.append(
+                        download_file(session, str(file.url), dest_path)
+                    )
+
+                try:
+                    await asyncio.gather(*download_tasks)
+                except HTTPException as e:
+                    return ExecutionResponse(
+                        success=False,
+                        output="",
+                        result_hash="",
+                        error=e.detail,
+                        hash_match=None,
+                    )
+
+        code_path = os.path.join(tmp_dir, "submission.py")
+        with open(code_path, "w") as f:
+            f.write(code)
+        os.chmod(code_path, 0o444)
+
+        if answer_path == "stdout":
+            cmd = ["python", "submission.py"]
+        else:
+            cmd = [
+                "sh",
+                "-c",
+                f"python submission.py && cat {answer_path} || echo 'EXECUTION_FAILED'",
+            ]
+
+        try:
+            result = await asyncio.to_thread(
+                run_container_safely,
+                tmp_dir,
+                cmd,
+                bound_files,
+                CONTAINER_TIMEOUT,
+            )
+        except Exception as e:
+            logger.error(f"Container execution failed: {str(e)}")
+            return ExecutionResponse(
+                success=False,
+                output="",
+                result_hash="",
+                error=f"Execution failed: {str(e)}",
+                hash_match=None,
+            )
+
+        output = result["stdout"]
+        error = result["stderr"]
+        success = result["status"] == 0
+
+        if answer_path != "stdout" and not output:
+            error += "\nNo output captured - check answer file path"
+
+        result_hash = hashlib.sha256(output.encode()).hexdigest()
+
+        return ExecutionResponse(
+            success=success,
+            hash_match=(
+                result_hash == request.expected_hash
+                if request.expected_hash
+                else None
+            ),
+            output=output[:5000],
+            result_hash=result_hash,
+            error=error[:5000],
+        )
+
+
+@app.get("/health", response_model=HealthCheckResponse)
+async def health_check() -> HealthCheckResponse:
+    try:
+        docker_client.ping()
+        return HealthCheckResponse(status="healthy", docker="connected")
+    except docker.errors.DockerException:
+        return HealthCheckResponse(status="degraded", docker="unavailable")
+
+
+def validate_file_path(path: str) -> bool:
+    return (
+        not os.path.isabs(path)
+        and os.path.basename(path) == path
+        and all(c.isalnum() or c in {"_", "-", "."} for c in path)
+    )

services/checker/pyproject.toml

@@ -0,0 +1,13 @@
+[project]
+name = "checker"
+version = "0.1.0"
+readme = "README.md"
+requires-python = ">=3.11"
+dependencies = [
+    "aiohttp>=3.11.13",
+    "docker>=7.1.0",
+    "fastapi>=0.115.11",
+    "python-multipart>=0.0.20",
+    "regex>=2024.11.6",
+    "uvicorn>=0.34.0",
+]

services/checker/scripts/check

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+GREEN='\033[1;32m'
+NC='\033[0m'
+
+uvx ruff format .
+uvx ruff check . --fix
+printf "${GREEN}Linters/formatters runned${NC}\n"

services/frontend/src/pages/CompetitionSession/index.tsx

@@ -45,6 +45,7 @@ const CompetitionSession = () => {
   }
 
   const handleSubmit = () => {
+    console.log(currentTask, competitionId, answer)
     if (!currentTask || !competitionId || !answer.trim()) return;
     submitMutation.mutate();
   };

services/frontend/src/shared/api/session.ts

@@ -20,11 +20,10 @@ export const submitTaskSolution = async (
   solution: string | File
 ) => {
   const endpoint = `/competitions/${competitionId}/tasks/${taskId}/submit`;
-  
   if (typeof solution === 'string') {
     return await userFetch(endpoint, {
       method: 'POST',
-      body: { answer: solution }
+      body: { content: solution }
     });
   } else {
     const formData = new FormData();