Following API definition.

The select method  must return the file from shacache.
And the download method should return the file content instead of path.

slapos/libnetworkcache/__init__.py

@@ -18,6 +18,7 @@ import hashlib
 import httplib
 import json
 import os
+import tempfile
 from urllib import urlretrieve
 from urlparse import urlparse
 
@@ -136,16 +137,22 @@ class NetworkcacheClient(object):
 
     return json.loads(data)
 
-  def download(self, path, sha512sum):
+  def download(self, sha512sum):
     ''' Download the file.
     It uses http GET request method.
     '''
     sha_cache_url = os.path.join(self.shacache_url, sha512sum)
-    path, headers = urlretrieve(sha_cache_url, path)
-    return headers
+    path, headers = urlretrieve(sha_cache_url, tempfile.mktemp())
+    f = open(path)
+    try:
+      file_content = f.read()
+    finally:
+      f.close()
+
+    return file_content
 
   def select(self, directory_key=None):
-    '''Download a file from shacache by selecting the entry in shadir
+    ''' Download a file from shacache by selecting the entry in shadir
     Raise DirectoryNotFound if multiple files are found.
     '''
     path_info = self.shadir_path
@@ -165,14 +172,12 @@ class NetworkcacheClient(object):
 
     data_list = json.loads(data)
     if len(data_list) > 1:
-      raise MultipleFileFoundError('Too many entries for a given directory. ' \
+      raise DirectoryNotFound('Too many entries for a given directory. ' \
                'Directory: %s. Entries: %s.' % (directory_key, str(data_list)))
 
-    return data_list
-
-
-class MultipleFileFoundError(Exception):
-  pass
+    information_dict, signature = data_list[0]
+    sha512 = information_dict.get('sha512')
+    return self.download(sha512)
 
 
 class DirectoryNotFound(Exception):