#!/usr/bin/env python # # Copyright (C) 2020 GNS3 Technologies Inc. # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see . import asyncio import signal import os from fastapi import FastAPI from pydantic import ValidationError from watchfiles import awatch, Change from typing import List from sqlalchemy import event from sqlalchemy.engine import Engine from sqlalchemy.exc import SQLAlchemyError from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession from alembic import command, config from alembic.script import ScriptDirectory from alembic.runtime.migration import MigrationContext from gns3server.db.repositories.computes import ComputesRepository from gns3server.db.repositories.images import ImagesRepository from gns3server.utils.images import discover_images, check_valid_image_header, read_image_info, default_images_directory, InvalidImageError from gns3server import schemas from .models import Base from gns3server.config import Config import logging log = logging.getLogger(__name__) def run_upgrade(connection, cfg): cfg.attributes["connection"] = connection command.upgrade(cfg, "head") def run_stamp(connection, cfg): cfg.attributes["connection"] = connection command.stamp(cfg, 'head') def check_revision(connection, cfg): script = ScriptDirectory.from_config(cfg) head_rev = script.get_revision("head").revision context = MigrationContext.configure(connection) current_rev = context.get_current_revision() return current_rev, head_rev async def connect_to_db(app: FastAPI) -> None: db_path = os.path.join(Config.instance().config_dir, "gns3_controller.db") db_url = os.environ.get("GNS3_DATABASE_URI", f"sqlite+aiosqlite:///{db_path}") engine = create_async_engine(db_url, connect_args={"check_same_thread": False}, future=True) alembic_cfg = config.Config() alembic_cfg.set_main_option("script_location", "gns3server:db_migrations") #alembic_cfg.set_main_option('sqlalchemy.url', db_url) try: async with engine.connect() as conn: current_rev, head_rev = await conn.run_sync(check_revision, alembic_cfg) log.info(f"Current database revision is {current_rev}") if current_rev is None: await conn.run_sync(Base.metadata.create_all) await conn.run_sync(run_stamp, alembic_cfg) elif current_rev != head_rev: # upgrade the database if needed await conn.run_sync(run_upgrade, alembic_cfg) await conn.commit() app.state._db_engine = engine except SQLAlchemyError as e: log.fatal(f"Error while connecting to database '{db_url}: {e}") async def disconnect_from_db(app: FastAPI) -> None: # dispose of the connection pool used by the database engine if getattr(app.state, "_db_engine"): await app.state._db_engine.dispose() log.info(f"Disconnected from database") @event.listens_for(Engine, "connect") def set_sqlite_pragma(dbapi_connection, connection_record): # Enable SQL foreign key support for SQLite # https://docs.sqlalchemy.org/en/14/dialects/sqlite.html#foreign-key-support cursor = dbapi_connection.cursor() cursor.execute("PRAGMA foreign_keys=ON") cursor.close() async def get_computes(app: FastAPI) -> List[dict]: computes = [] async with AsyncSession(app.state._db_engine) as db_session: db_computes = await ComputesRepository(db_session).get_computes() for db_compute in db_computes: try: compute = schemas.Compute.from_orm(db_compute) except ValidationError as e: log.error(f"Could not load compute '{db_compute.compute_id}' from database: {e}") continue computes.append(compute) return computes def image_filter(change: Change, path: str) -> bool: if change == Change.added and os.path.isfile(path): if path.endswith(".tmp") or path.endswith(".md5sum") or path.startswith("."): return False if "/lib/" in path or "/lib64/" in path: # ignore custom IOU libraries return False header_magic_len = 7 with open(path, "rb") as f: image_header = f.read(header_magic_len) # read the first 7 bytes of the file if len(image_header) >= header_magic_len: try: check_valid_image_header(image_header) except InvalidImageError as e: log.debug(f"New image '{path}': {e}") return False else: log.debug(f"New image '{path}': size is too small to be valid") return False return True # FIXME: should we support image deletion? # elif change == Change.deleted: # return True return False async def monitor_images_on_filesystem(app: FastAPI): directories_to_monitor = [] for image_type in ("qemu", "ios", "iou"): image_dir = default_images_directory(image_type) if os.path.isdir(image_dir): log.debug(f"Monitoring for new images in '{image_dir}'") directories_to_monitor.append(image_dir) try: async for changes in awatch( *directories_to_monitor, watch_filter=image_filter, raise_interrupt=True ): async with AsyncSession(app.state._db_engine) as db_session: images_repository = ImagesRepository(db_session) for change in changes: change_type, image_path = change if change_type == Change.added: try: image = await read_image_info(image_path) except InvalidImageError as e: log.warning(str(e)) continue try: if await images_repository.get_image(image_path): continue await images_repository.add_image(**image) log.info(f"Discovered image '{image_path}' has been added to the database") except SQLAlchemyError as e: log.warning(f"Error while adding image '{image_path}' to the database: {e}") # if change_type == Change.deleted: # try: # if await images_repository.get_image(image_path): # success = await images_repository.delete_image(image_path) # if not success: # log.warning(f"Could not delete image '{image_path}' from the database") # else: # log.info(f"Image '{image_path}' has been deleted from the database") # except SQLAlchemyError as e: # log.warning(f"Error while deleting image '{image_path}' from the database: {e}") except KeyboardInterrupt: # send SIGTERM to the server PID so uvicorn can shutdown the process os.kill(os.getpid(), signal.SIGTERM) async def discover_images_on_filesystem(app: FastAPI): async with AsyncSession(app.state._db_engine) as db_session: images_repository = ImagesRepository(db_session) db_images = await images_repository.get_images() existing_image_paths = [] for db_image in db_images: try: image = schemas.Image.from_orm(db_image) existing_image_paths.append(image.path) except ValidationError as e: log.error(f"Could not load image '{db_image.filename}' from database: {e}") continue for image_type in ("qemu", "ios", "iou"): discovered_images = await discover_images(image_type, existing_image_paths) for image in discovered_images: log.info(f"Adding discovered image '{image['path']}' to the database") try: await images_repository.add_image(**image) except SQLAlchemyError as e: log.warning(f"Error while adding image '{image['path']}' to the database: {e}") # monitor if images have been manually added asyncio.create_task(monitor_images_on_filesystem(app))