The directory key can not be always the same.

So, a new method has been implemented in order to define the directory
key for each file which the buildout must download.

src/zc/buildout/networkcache.py

@@ -20,7 +20,8 @@ import re
 import urllib
 import urlparse
 from download import check_md5sum
-from slapos.libnetworkcache import NetworkcacheClient, UploadError
+from slapos.libnetworkcache import NetworkcacheClient, UploadError, \
+                                   MultipleFileFoundError, DirectoryNotFound
 
 
 _md5_re = re.compile(r'md5=([a-f0-9]+)')
@@ -33,18 +34,26 @@ def _get_md5_from_url(url):
   return None
 
 
+def get_directory_key(url):
+    """It must retorn the directory key based on the URL.
+
+    Basically check if the url belongs to pypi:
+      - if yes, the directory key will be pypi-buildout-urlmd5
+      - if not, the directory key will be slapos-buildout-urlmd5
+    """
+    urlmd5 = hashlib.md5(url).hexdigest()
+    if 'pypi' in url:
+      return 'pypi-buildout-%s' % urlmd5
+    return 'slapos-buildout-%s' % urlmd5
+
 def select_sha512sum_from_shadir(sha_dir, url, logger):
     """It must return the sha512sum if exists on selected directory. """
-    # On buildout.cfg the option sha-dir is the complete link including the
-    # directory key, so we must to extract it to use the libnetworkcache
-    # correctly.
-    directory_key = sha_dir.split('/')[-1]
-    sha_dir_without_directory_key = '/'.join(sha_dir.split('/')[:-1])
+    directory_key = get_directory_key(url)
 
     try:
-      nc = NetworkcacheClient(shadir=sha_dir_without_directory_key)
+      nc = NetworkcacheClient(shadir=sha_dir)
       data_list = nc.select(directory_key)
-    except (IOError, UploadError), e:
+    except (IOError, DirectoryNotFound, MultipleFileFoundError), e:
       logger.info('Could not retrieve the information from SHADIR. %s' % e)
       return None
 
@@ -98,20 +107,14 @@ def upload_network_cached(sha_cache, sha_dir, external_url, path, logger):
              'Upload cache ignored, shacache or shadir was not provided!')
         return False
 
-    # On buildout.cfg the option sha-dir is the complete link including the
-    # directory key, so we must to extract it to use the libnetworkcache
-    # correctly.
-    directory_key = sha_dir.split('/')[-1]
-    sha_dir_without_directory_key = '/'.join(sha_dir.split('/')[:-1])
-
-    f = open(path, 'r')
-    try:
-
+    directory_key = get_directory_key(external_url)
     kw = dict(file_name=os.path.basename(external_url),
               urlmd5=hashlib.md5(external_url).hexdigest())
 
+    f = open(path, 'r')
+    try:
         nc = NetworkcacheClient(shacache=sha_cache,
-                                shadir=sha_dir_without_directory_key)
+                                shadir=sha_dir)
         data = nc.upload(f, directory_key, **kw)
     except (IOError, UploadError), e:
         logger.info('Fail to upload file. %s' % \