gns3-server/gns3server/db/repositories/images.py

#!/usr/bin/env python
#
# Copyright (C) 2021 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 <http://www.gnu.org/licenses/>.

import os

from typing import Optional, List, cast
from sqlalchemy import select, delete, update
from sqlalchemy.engine import CursorResult
from sqlalchemy.ext.asyncio import AsyncSession

from .base import BaseRepository

import gns3server.db.models as models

import logging

log = logging.getLogger(__name__)


class ImagesRepository(BaseRepository):
    def __init__(self, db_session: AsyncSession) -> None:

        super().__init__(db_session)

    async def get_image(self, image_path: str) -> Optional[models.Image]:
        """
        Get an image by its path.
        """

        image_dir, image_name = os.path.split(image_path)
        if image_dir:
            query = select(models.Image).where(
                models.Image.filename == image_name, models.Image.path.endswith(image_path)
            )
        else:
            query = select(models.Image).where(models.Image.filename == image_name)
        result = await self._db_session.execute(query)
        return result.scalars().one_or_none()

    async def get_image_by_checksum(self, checksum: str, image_dir: Optional[str] = None) -> Optional[models.Image]:
        """
        Get an image by its checksum.
        """

        if image_dir:
            query = select(models.Image).where(
                models.Image.checksum == checksum, models.Image.path.startswith(image_dir)
            )
            result = await self._db_session.execute(query)
            return result.scalars().one_or_none()
        else:
            query = select(models.Image).where(models.Image.checksum == checksum)
            result = await self._db_session.execute(query)
            return result.scalars().first()

    async def get_images(self, image_type=None) -> List[models.Image]:
        """
        Get all images.
        """

        if image_type:
            query = select(models.Image).where(models.Image.image_type == image_type)
        else:
            query = select(models.Image)
        result = await self._db_session.execute(query)
        return list(result.scalars().all())

    async def get_image_templates(self, image_id: int) -> List[models.Template]:
        """
        Get all templates that an image belongs to.
        """

        query = select(models.Template).join(models.Template.images).filter(models.Image.image_id == image_id)

        result = await self._db_session.execute(query)
        return list(result.scalars().all())

    async def add_image(self, image_name, image_type, image_size, path, checksum, checksum_algorithm) -> models.Image:
        """
        Create a new image.
        """

        db_image = models.Image(
            image_id=None,
            filename=image_name,
            image_type=image_type,
            image_size=image_size,
            path=path,
            checksum=checksum,
            checksum_algorithm=checksum_algorithm,
        )

        self._db_session.add(db_image)
        await self._db_session.commit()
        await self._db_session.refresh(db_image)
        return db_image

    async def update_image(self, image_path: str, checksum: str, checksum_algorithm: str) -> Optional[models.Image]:
        """
        Update an image.
        """

        query = (
            update(models.Image)
            .where(models.Image.path == image_path)
            .values(checksum=checksum, checksum_algorithm=checksum_algorithm)
        )

        await self._db_session.execute(query)
        await self._db_session.commit()
        image_db = await self.get_image(image_path)
        if image_db:
            await self._db_session.refresh(image_db)  # force refresh of updated_at value
        return image_db

    async def delete_image(self, image_path: str) -> bool:
        """
        Delete an image.
        """

        image_dir, image_name = os.path.split(image_path)
        if image_dir:
            query = (
                delete(models.Image)
                .where(models.Image.filename == image_name, models.Image.path.endswith(image_path))
                .execution_options(synchronize_session=False)
            )
        else:
            query = delete(models.Image).where(models.Image.filename == image_name)
        result = await self._db_session.execute(query)
        await self._db_session.commit()
        return cast(CursorResult, result).rowcount > 0

    async def prune_images(self, skip_images: Optional[list[str]] = None) -> int:
        """
        Prune images not attached to any template.
        """

        query = select(models.Image).filter(~models.Image.templates.any())
        result = await self._db_session.execute(query)
        images = result.scalars().all()
        images_deleted = 0
        for image in images:
            if skip_images and image.filename in skip_images:
                log.debug(f"Skipping image '{image.path}' for pruning")
                continue
            try:
                log.debug(f"Deleting image '{image.path}'")
                os.remove(image.path)
            except OSError:
                log.warning(f"Could not delete image file {image.path}")
            if await self.delete_image(image.path):
                images_deleted += 1
        log.info(f"{images_deleted} image(s) have been deleted")
        return images_deleted