Efforts to make ucloud a python package

ucloud/common/storage_handlers.py

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+import shutil
+import subprocess as sp
+import os
+import stat
+
+from abc import ABC
+from . import logger
+from os.path import join as join_path
+
+
+class ImageStorageHandler(ABC):
+    def __init__(self, image_base, vm_base):
+        self.image_base = image_base
+        self.vm_base = vm_base
+
+    def import_image(self, image_src, image_dest, protect=False):
+        """Put an image at the destination
+        :param src: An Image file
+        :param dest: A path where :param src: is to be put.
+        :param protect: If protect is true then the dest is protect (readonly etc)
+        The obj must exist on filesystem.
+        """
+
+        raise NotImplementedError()
+
+    def make_vm_image(self, image_path, path):
+        """Copy image from src to dest
+
+        :param src: A path
+        :param dest: A path
+
+        src and destination must be on same storage system i.e both on file system or both on CEPH etc.
+        """
+        raise NotImplementedError()
+
+    def resize_vm_image(self, path, size):
+        """Resize image located at :param path:
+        :param path: The file which is to be resized
+        :param size: Size must be in Megabytes
+        """
+        raise NotImplementedError()
+
+    def delete_vm_image(self, path):
+        raise NotImplementedError()
+
+    def execute_command(self, command, report=True):
+        command = list(map(str, command))
+        try:
+            output = sp.check_output(command, stderr=sp.PIPE)
+        except Exception as e:
+            if report:
+                print(e)
+                logger.exception(e)
+            return False
+        return True
+
+    def vm_path_string(self, path):
+        raise NotImplementedError()
+
+    def qemu_path_string(self, path):
+        raise NotImplementedError()
+
+    def is_vm_image_exists(self, path):
+        raise NotImplementedError()
+
+
+class FileSystemBasedImageStorageHandler(ImageStorageHandler):
+    def import_image(self, src, dest, protect=False):
+        dest = join_path(self.image_base, dest)
+        try:
+            shutil.copy(src, dest)
+            if protect:
+                os.chmod(dest, stat.S_IRUSR | stat.S_IRGRP | stat.S_IROTH)
+        except Exception as e:
+            logger.exception(e)
+            return False
+        return True
+
+    def make_vm_image(self, src, dest):
+        src = join_path(self.image_base, src)
+        dest = join_path(self.vm_base, dest)
+        try:
+            shutil.copy(src, dest)
+        except Exception as e:
+            logger.exception(e)
+            return False
+        return True
+
+    def resize_vm_image(self, path, size):
+        path = join_path(self.vm_base, path)
+        command = ["qemu-img", "resize", "-f", "raw", path, "{}M".format(size)]
+        if self.execute_command(command):
+            return True
+        else:
+            self.delete_vm_image(path)
+            return False
+
+    def delete_vm_image(self, path):
+        path = join_path(self.vm_base, path)
+        try:
+            os.remove(path)
+        except Exception as e:
+            logger.exception(e)
+            return False
+        return True
+
+    def vm_path_string(self, path):
+        return join_path(self.vm_base, path)
+
+    def qemu_path_string(self, path):
+        return self.vm_path_string(path)
+
+    def is_vm_image_exists(self, path):
+        path = join_path(self.vm_base, path)
+        command = ["ls", path]
+        return self.execute_command(command, report=False)
+
+
+class CEPHBasedImageStorageHandler(ImageStorageHandler):
+    def import_image(self, src, dest, protect=False):
+        dest = join_path(self.image_base, dest)
+        command = ["rbd", "import", src, dest]
+        if protect:
+            snap_create_command = ["rbd", "snap", "create", "{}@protected".format(dest)]
+            snap_protect_command = ["rbd", "snap", "protect", "{}@protected".format(dest)]
+
+            return self.execute_command(command) and self.execute_command(snap_create_command) and\
+                self.execute_command(snap_protect_command)
+
+        return self.execute_command(command)
+
+    def make_vm_image(self, src, dest):
+        src = join_path(self.image_base, src)
+        dest = join_path(self.vm_base, dest)
+
+        command = ["rbd", "clone", "{}@protected".format(src), dest]
+        return self.execute_command(command)
+
+    def resize_vm_image(self, path, size):
+        path = join_path(self.vm_base, path)
+        command = ["rbd", "resize", path, "--size", size]
+        return self.execute_command(command)
+
+    def delete_vm_image(self, path):
+        path = join_path(self.vm_base, path)
+        command = ["rbd", "rm", path]
+        return self.execute_command(command)
+
+    def vm_path_string(self, path):
+        return join_path(self.vm_base, path)
+
+    def qemu_path_string(self, path):
+        return "rbd:{}".format(self.vm_path_string(path))
+
+    def is_vm_image_exists(self, path):
+        path = join_path(self.vm_base, path)
+        command = ["rbd", "info", path]
+        return self.execute_command(command, report=False)