Uses oslo.imageutils

Commit 035668 had the QemuImgInfo class moved to Oslo.
This class was copied from Nova to Cinder and diverged since then.
The two projects will be able to use identical classes by importing imageutils.

Change-Id: If1962680906b3736d3f16f306b077483b122f878

nova/openstack/common/imageutils.py

@@ -0,0 +1,144 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2010 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# All Rights Reserved.
+# Copyright (c) 2010 Citrix Systems, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""
+Helper methods to deal with images.
+"""
+
+import re
+
+from nova.openstack.common.gettextutils import _  # noqa
+from nova.openstack.common import strutils
+
+
+class QemuImgInfo(object):
+    BACKING_FILE_RE = re.compile((r"^(.*?)\s*\(actual\s+path\s*:"
+                                  r"\s+(.*?)\)\s*$"), re.I)
+    TOP_LEVEL_RE = re.compile(r"^([\w\d\s\_\-]+):(.*)$")
+    SIZE_RE = re.compile(r"\(\s*(\d+)\s+bytes\s*\)", re.I)
+
+    def __init__(self, cmd_output=None):
+        details = self._parse(cmd_output or '')
+        self.image = details.get('image')
+        self.backing_file = details.get('backing_file')
+        self.file_format = details.get('file_format')
+        self.virtual_size = details.get('virtual_size')
+        self.cluster_size = details.get('cluster_size')
+        self.disk_size = details.get('disk_size')
+        self.snapshots = details.get('snapshot_list', [])
+        self.encryption = details.get('encryption')
+
+    def __str__(self):
+        lines = [
+            'image: %s' % self.image,
+            'file_format: %s' % self.file_format,
+            'virtual_size: %s' % self.virtual_size,
+            'disk_size: %s' % self.disk_size,
+            'cluster_size: %s' % self.cluster_size,
+            'backing_file: %s' % self.backing_file,
+        ]
+        if self.snapshots:
+            lines.append("snapshots: %s" % self.snapshots)
+        return "\n".join(lines)
+
+    def _canonicalize(self, field):
+        # Standardize on underscores/lc/no dash and no spaces
+        # since qemu seems to have mixed outputs here... and
+        # this format allows for better integration with python
+        # - ie for usage in kwargs and such...
+        field = field.lower().strip()
+        for c in (" ", "-"):
+            field = field.replace(c, '_')
+        return field
+
+    def _extract_bytes(self, details):
+        # Replace it with the byte amount
+        real_size = self.SIZE_RE.search(details)
+        if real_size:
+            details = real_size.group(1)
+        try:
+            details = strutils.to_bytes(details)
+        except TypeError:
+            pass
+        return details
+
+    def _extract_details(self, root_cmd, root_details, lines_after):
+        real_details = root_details
+        if root_cmd == 'backing_file':
+            # Replace it with the real backing file
+            backing_match = self.BACKING_FILE_RE.match(root_details)
+            if backing_match:
+                real_details = backing_match.group(2).strip()
+        elif root_cmd in ['virtual_size', 'cluster_size', 'disk_size']:
+            # Replace it with the byte amount (if we can convert it)
+            real_details = self._extract_bytes(root_details)
+        elif root_cmd == 'file_format':
+            real_details = real_details.strip().lower()
+        elif root_cmd == 'snapshot_list':
+            # Next line should be a header, starting with 'ID'
+            if not lines_after or not lines_after[0].startswith("ID"):
+                msg = _("Snapshot list encountered but no header found!")
+                raise ValueError(msg)
+            del lines_after[0]
+            real_details = []
+            # This is the sprintf pattern we will try to match
+            # "%-10s%-20s%7s%20s%15s"
+            # ID TAG VM SIZE DATE VM CLOCK (current header)
+            while lines_after:
+                line = lines_after[0]
+                line_pieces = line.split()
+                if len(line_pieces) != 6:
+                    break
+                # Check against this pattern in the final position
+                # "%02d:%02d:%02d.%03d"
+                date_pieces = line_pieces[5].split(":")
+                if len(date_pieces) != 3:
+                    break
+                real_details.append({
+                    'id': line_pieces[0],
+                    'tag': line_pieces[1],
+                    'vm_size': line_pieces[2],
+                    'date': line_pieces[3],
+                    'vm_clock': line_pieces[4] + " " + line_pieces[5],
+                })
+                del lines_after[0]
+        return real_details
+
+    def _parse(self, cmd_output):
+        # Analysis done of qemu-img.c to figure out what is going on here
+        # Find all points start with some chars and then a ':' then a newline
+        # and then handle the results of those 'top level' items in a separate
+        # function.
+        #
+        # TODO(harlowja): newer versions might have a json output format
+        #                 we should switch to that whenever possible.
+        #                 see: http://bit.ly/XLJXDX
+        contents = {}
+        lines = [x for x in cmd_output.splitlines() if x.strip()]
+        while lines:
+            line = lines.pop(0)
+            top_level = self.TOP_LEVEL_RE.match(line)
+            if top_level:
+                root = self._canonicalize(top_level.group(1))
+                if not root:
+                    continue
+                root_details = top_level.group(2).strip()
+                details = self._extract_details(root, root_details, lines)
+                contents[root] = details
+        return contents

openstack-common.conf

@@ -12,6 +12,7 @@ module=fileutils
 module=fixture
 module=flakes
 module=gettextutils
+module=imageutils
 module=importutils
 module=install_venv_common
 module=jsonutils