Replace lockfile by oslo_concurrency

This drops lockfile in favor of oslo_concurrency in order to unify
Horizon with the rest of the OpenStack projects.

Change-Id: I245fa3ca3926c279cb760f1d4530c511b140a8ea

horizon/utils/secret_key.py

@@ -17,7 +17,7 @@ import os
 import random
 import string
 
-import lockfile
+from oslo_concurrency import lockutils
 
 
 class FilePermissionError(Exception):
@@ -48,7 +48,9 @@ def generate_or_read_from_file(key_file='.secret_key', key_length=64):
     environment).  Also checks if file permissions are set correctly and
     throws an exception if not.
     """
-    lock = lockfile.FileLock(key_file)
+    abspath = os.path.abspath(key_file)
+    lock = lockutils.external_lock(key_file + ".lock",
+                                   lock_path=os.path.dirname(abspath))
     with lock:
         if not os.path.exists(key_file):
             key = generate_key(key_length)

requirements.txt

@@ -19,10 +19,8 @@ eventlet>=0.15.2
 httplib2>=0.7.5
 iso8601>=0.1.9
 kombu>=2.5.0
-# Horizon Utility Requirements
-# for SECURE_KEY generation
-lockfile>=0.8
 netaddr>=0.7.12
+oslo.concurrency>=1.4.1  # Apache-2.0
 oslo.config>=1.6.0  # Apache-2.0
 oslo.i18n>=1.0.0  # Apache-2.0
 oslo.serialization>=1.2.0               # Apache-2.0