# This file is part of cloud-init. See LICENSE file for license information.

"""NoCloud KVM Image Base Class."""

from cloudinit import subp

import os
import shutil
import tempfile

from ..images import Image
from .snapshot import NoCloudKVMSnapshot


class NoCloudKVMImage(Image):
    """NoCloud KVM backed image."""

    platform_name = "nocloud-kvm"

    def __init__(self, platform, config, orig_img_path):
        """Set up image.

        @param platform: platform object
        @param config: image configuration
        @param img_path: path to the image
        """
        self.modified = False
        self._workd = tempfile.mkdtemp(prefix='NoCloudKVMImage')
        self._orig_img_path = orig_img_path
        self._img_path = os.path.join(self._workd,
                                      os.path.basename(self._orig_img_path))

        subp.subp(['qemu-img', 'create', '-f', 'qcow2',
                   '-b', orig_img_path, self._img_path])

        super(NoCloudKVMImage, self).__init__(platform, config)

    def _execute(self, command, stdin=None, env=None):
        """Execute command in image, modifying image."""
        return self.mount_image_callback(command, stdin=stdin, env=env)

    def mount_image_callback(self, command, stdin=None, env=None):
        """Run mount-image-callback."""

        env_args = []
        if env:
            env_args = ['env'] + ["%s=%s" for k, v in env.items()]

        mic_chroot = ['sudo', 'mount-image-callback', '--system-mounts',
                      '--system-resolvconf', self._img_path,
                      '--', 'chroot', '_MOUNTPOINT_']
        try:
            out, err = subp.subp(mic_chroot + env_args + list(command),
                                 data=stdin, decode=False)
            return (out, err, 0)
        except subp.ProcessExecutionError as e:
            return (e.stdout, e.stderr, e.exit_code)

    def snapshot(self):
        """Create snapshot of image, block until done."""
        if not self._img_path:
            raise RuntimeError()

        return NoCloudKVMSnapshot(self.platform, self.properties, self.config,
                                  self.features, self._img_path)

    def destroy(self):
        """Unset path to signal image is no longer used.

        The removal of the images and all other items is handled by the
        framework. In some cases we want to keep the images, so let the
        framework decide whether to keep or destroy everything.
        """
        self._img_path = None
        shutil.rmtree(self._workd)

        super(NoCloudKVMImage, self).destroy()

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