improve tarball loading and check md5 from repository

installsystems/image.py

@@ -17,6 +17,7 @@ import re
 import shutil
 import gzip
 import gzipstream #until python support gzip not seekable
+import cStringIO
 import installsystems.template as istemplate
 import installsystems.tools as istools
 from installsystems.printer import *
@@ -359,7 +360,12 @@ class PackageImage(Image):
         try:
             if fileobj is None:
                 fileobj = istools.uopen(self.path)
-                self._tarball = Tarball.open(fileobj=fileobj, mode='r:gz')
+            memfile = cStringIO.StringIO()
+            fileobj.seek(0)
+            (self.size, self.md5) = istools.copyfileobj(fileobj, memfile)
+            fileobj.close()
+            memfile.seek(0)
+            self._tarball = Tarball.open(fileobj=memfile, mode='r:gz')
         except Exception as e:
             raise Exception("Unable to open image %s: %s" % (path, e))
         self._metadata = self.read_metadata()

installsystems/repository.py

@@ -277,19 +277,23 @@ class Repository(object):
         r = self.db.ask("select md5 from image where name = ? and version = ? limit 1",
                         (name, version)).fetchone()
         if r is None:
-            raise Exception("Unable to find image %s version %s" % (name, version))
+            raise Exception("Unable to find image %s v%s" % (name, version))
         path = os.path.join(self.config.path, r[0])
         # getting the file
         arrow("Loading image %s v%s from repository %s" % (name,
                                                            version,
                                                            self.config.name))
         memfile = cStringIO.StringIO()
-        fo = istools.uopen(path)
-        (self.size, self.md5) = istools.copyfileobj(fo, memfile)
-        fo.close()
+        try:
+            fo = istools.uopen(path)
+            istools.copyfileobj(fo, memfile)
+            fo.close()
+        except Exception as e:
+            raise Exception("Loading image %s v%s failed: %s" % (name, version, e))
         memfile.seek(0)
         pkg = PackageImage(path, fileobj=memfile, md5name=True)
-        pkg.md5 = r[0]
+        if pkg.md5 != r[0]:
+            raise Exception("Image MD5 verification failure")
         return pkg
 
     def getmd5(self, name, version):