1 files changed, 81 insertions, 0 deletions
diff --git a/morphlib/mountableimage.py b/morphlib/mountableimage.py
new file mode 100644
index 00000000..3d29a516
--- /dev/null
+++ b/morphlib/mountableimage.py
@@ -0,0 +1,81 @@
+# Copyright (C) 2012-2013  Codethink Limited
+#
+# 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; version 2 of the License.
+#
+# 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, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import cliapp
+import os
+import tempfile
+import gzip
+
+import morphlib
+
+
+class MountableImage(object): # pragma: no cover
+
+    '''Mountable image (deals with decompression).
+
+    Note, this is a read-only mount in the sense that the decompressed
+    image is not then recompressed after, instead any changes are discarded.
+
+    '''
+    def __init__(self, app, artifact_path):
+        self.app = app
+        self.artifact_path = artifact_path
+
+    def setup(self, path):
+        self.app.status(msg='Preparing image %(path)s', path=path, chatty=True)
+        self.app.status(msg='  Decompressing...', chatty=True)
+        (tempfd, self.temp_path) = \
+            tempfile.mkstemp(dir=self.app.settings['tempdir'])
+
+        try:
+            with os.fdopen(tempfd, "wb") as outfh:
+                infh = gzip.open(path, "rb")
+                morphlib.util.copyfileobj(infh, outfh)
+                infh.close()
+        except:
+            os.unlink(self.temp_path)
+            raise
+        self.app.status(msg='  Mounting image at %(path)s',
+                        path=self.temp_path, chatty=True)
+        part = morphlib.fsutils.setup_device_mapping(self.app.runcmd,
+                                                     self.temp_path)
+        mount_point = tempfile.mkdtemp(dir=self.app.settings['tempdir'])
+        morphlib.fsutils.mount(self.app.runcmd, part, mount_point)
+        self.mount_point = mount_point
+        return mount_point
+
+    def cleanup(self, path, mount_point):
+        self.app.status(msg='Clearing down image at %(path)s', path=path,
+                        chatty=True)
+        try:
+            morphlib.fsutils.unmount(self.app.runcmd, mount_point)
+        except:
+            pass
+        try:
+            morphlib.fsutils.undo_device_mapping(self.app.runcmd, path)
+        except:
+            pass
+        try:
+            os.rmdir(mount_point)
+            os.unlink(path)
+        except:
+            pass
+
+    def __enter__(self):
+        return self.setup(self.artifact_path)
+
+    def __exit__(self, exctype, excvalue, exctraceback):
+        self.cleanup(self.temp_path, self.mount_point)