server/tasks/task_2_docker_runtime.py

"""Task 2: Dockerfile Runtime Errors — MEDIUM.

Agent fixes Dockerfiles that build successfully but fail at container
runtime: missing WORKDIR, CMD/ENTRYPOINT conflicts, permission issues,
and missing environment variables.
"""



from server.models import TaskDifficulty
from server.tasks.base import BaseTask


class DockerfileRuntimeTask(BaseTask):
    NAME = "Dockerfile Runtime Errors"
    DESCRIPTION = "Fix runtime/container execution issues in Dockerfiles"
    DIFFICULTY = TaskDifficulty.MEDIUM
    AVAILABLE_SECRETS = []

    SCENARIOS = [
        # Scenario 1: Missing WORKDIR — node module resolution fails at runtime
        {
            "id": "missing_workdir",
            "files": [
                {
                    "path": "Dockerfile",
                    "type": "dockerfile",
                    "content": (
                        "FROM node:18-alpine\n"
                        "COPY package*.json ./\n"
                        "RUN npm ci\n"
                        "COPY . .\n"
                        'CMD ["npm", "start"]'
                    ),
                },
                {
                    "path": "package.json",
                    "type": "other",
                    "content": '{"name": "app", "scripts": {"start": "node index.js"}}',
                },
            ],
            "error": {
                "phase": "docker_run",
                "message": "Error: Cannot find module '/package.json'",
                "exit_code": 1,
                "failed_step": "npm start",
            },
            "expected_fixes": [
                {
                    "file": "Dockerfile",
                    "type": "contains",
                    "expected": "WORKDIR /app",
                    "hint": "Set a working directory before COPY/RUN so files land in /app, not /",
                }
            ],
        },

        # Scenario 2: CMD and ENTRYPOINT both defined as full exec forms — conflict
        {
            "id": "cmd_entrypoint_conflict",
            "files": [
                {
                    "path": "Dockerfile",
                    "type": "dockerfile",
                    "content": (
                        "FROM python:3.11-slim\n"
                        "WORKDIR /app\n"
                        "COPY . .\n"
                        "RUN pip install -r requirements.txt\n"
                        'ENTRYPOINT ["python", "server.py"]\n'
                        'CMD ["python", "server.py"]'
                    ),
                },
                {
                    "path": "requirements.txt",
                    "type": "requirements",
                    "content": "flask==2.3.0",
                },
            ],
            "error": {
                "phase": "docker_run",
                "message": (
                    "container exits immediately; process started twice — "
                    "ENTRYPOINT and CMD both specify the full command"
                ),
                "exit_code": 1,
                "failed_step": "container start",
            },
            "expected_fixes": [
                {
                    "file": "Dockerfile",
                    "type": "not_contains",
                    "expected": 'CMD ["python", "server.py"]',
                    "hint": (
                        "When using ENTRYPOINT as a full command, CMD should provide "
                        "default arguments only, or be removed entirely"
                    ),
                }
            ],
        },

        # Scenario 3: Entrypoint script not executable
        {
            "id": "entrypoint_not_executable",
            "files": [
                {
                    "path": "Dockerfile",
                    "type": "dockerfile",
                    "content": (
                        "FROM python:3.11-slim\n"
                        "WORKDIR /app\n"
                        "COPY . .\n"
                        "RUN pip install -r requirements.txt\n"
                        'ENTRYPOINT ["./start.sh"]'
                    ),
                },
                {
                    "path": "requirements.txt",
                    "type": "requirements",
                    "content": "flask==2.3.0",
                },
                {
                    "path": "start.sh",
                    "type": "other",
                    "content": "#!/bin/bash\npython app.py",
                },
            ],
            "error": {
                "phase": "docker_run",
                "message": "exec ./start.sh: permission denied",
                "exit_code": 126,
                "failed_step": "ENTRYPOINT ./start.sh",
            },
            "expected_fixes": [
                {
                    "file": "Dockerfile",
                    "type": "contains",
                    "expected": "RUN chmod +x ./start.sh",
                    "hint": "The entrypoint script must be made executable with chmod +x before the ENTRYPOINT instruction",
                }
            ],
        },

        # Scenario 4: App crashes because a required ENV variable is missing
        {
            "id": "missing_required_env",
            "files": [
                {
                    "path": "Dockerfile",
                    "type": "dockerfile",
                    "content": (
                        "FROM python:3.11-slim\n"
                        "WORKDIR /app\n"
                        "COPY . .\n"
                        "RUN pip install -r requirements.txt\n"
                        "EXPOSE 8080\n"
                        'CMD ["python", "app.py"]'
                    ),
                },
                {
                    "path": "requirements.txt",
                    "type": "requirements",
                    "content": "flask==2.3.0\ngunicorn==21.2.0",
                },
            ],
            "error": {
                "phase": "docker_run",
                "message": (
                    "KeyError: 'DATABASE_URL'\n"
                    "Application requires DATABASE_URL environment variable to be set"
                ),
                "exit_code": 1,
                "failed_step": "python app.py",
            },
            "expected_fixes": [
                {
                    "file": "Dockerfile",
                    "type": "contains",
                    "expected": "ENV DATABASE_URL",
                    "hint": "Add an ENV instruction to set DATABASE_URL (use a default or placeholder value)",
                }
            ],
        },

        # Scenario 5: Non-root user can't bind to privileged port
        {
            "id": "non_root_privileged_port",
            "files": [
                {
                    "path": "Dockerfile",
                    "type": "dockerfile",
                    "content": (
                        "FROM python:3.11-slim\n"
                        "WORKDIR /app\n"
                        "COPY . .\n"
                        "RUN pip install -r requirements.txt\n"
                        "RUN useradd --create-home appuser\n"
                        "USER appuser\n"
                        "EXPOSE 80\n"
                        'CMD ["python", "app.py"]'
                    ),
                },
                {
                    "path": "requirements.txt",
                    "type": "requirements",
                    "content": "flask==2.3.0",
                },
            ],
            "error": {
                "phase": "docker_run",
                "message": (
                    "PermissionError: [Errno 13] Permission denied — "
                    "non-root user cannot bind to port 80"
                ),
                "exit_code": 1,
                "failed_step": "python app.py",
            },
            "expected_fixes": [
                {
                    "file": "Dockerfile",
                    "type": "contains",
                    "expected": "EXPOSE 8080",
                    "hint": "Non-root users cannot bind to ports below 1024 — use a higher port like 8080",
                }
            ],
        },
    ]