Merge "Fix portability issue"

oslo_rootwrap/cmd.py

@@ -33,7 +33,6 @@
 from __future__ import print_function
 
 import logging
-import resource
 import sys
 
 from oslo_rootwrap import subprocess
@@ -41,6 +40,12 @@ from oslo_rootwrap import wrapper
 
 from six import moves
 
+try:
+    # This isn't available on all platforms (e.g. Windows).
+    import resource
+except ImportError:
+    resource = None
+
 RC_UNAUTHORIZED = 99
 RC_NOCOMMAND = 98
 RC_BADCONFIG = 97
@@ -85,21 +90,23 @@ def main(run_daemon=False):
         _exit_error(execname, "Incorrect configuration file: %s" % configfile,
                     RC_BADCONFIG, log=False)
 
-    # When use close_fds=True on Python 2.x, we spend significant time
-    # in closing fds up to current soft ulimit, which could be large.
-    # Lower our ulimit to a reasonable value to regain performance.
-    fd_limits = resource.getrlimit(resource.RLIMIT_NOFILE)
-    sensible_fd_limit = min(config.rlimit_nofile, fd_limits[0])
-    if (fd_limits[0] > sensible_fd_limit):
-        # Unfortunately this inherits to our children, so allow them to
-        # re-raise by passing through the hard limit unmodified
-        resource.setrlimit(
-            resource.RLIMIT_NOFILE, (sensible_fd_limit, fd_limits[1]))
-        # This is set on import to the hard ulimit. if its defined we
-        # already have imported it, so we need to update it to the new limit
-        if (hasattr(subprocess, 'MAXFD') and
-                subprocess.MAXFD > sensible_fd_limit):
-            subprocess.MAXFD = sensible_fd_limit
+    if resource:
+        # When use close_fds=True on Python 2.x, we spend significant time
+        # in closing fds up to current soft ulimit, which could be large.
+        # Lower our ulimit to a reasonable value to regain performance.
+        fd_limits = resource.getrlimit(resource.RLIMIT_NOFILE)
+        sensible_fd_limit = min(config.rlimit_nofile, fd_limits[0])
+        if (fd_limits[0] > sensible_fd_limit):
+            # Unfortunately this inherits to our children, so allow them to
+            # re-raise by passing through the hard limit unmodified
+            resource.setrlimit(
+                resource.RLIMIT_NOFILE, (sensible_fd_limit, fd_limits[1]))
+            # This is set on import to the hard ulimit. if its defined we
+            # already have imported it, so we need to update it to the new
+            # limit.
+            if (hasattr(subprocess, 'MAXFD') and
+                    subprocess.MAXFD > sensible_fd_limit):
+                subprocess.MAXFD = sensible_fd_limit
 
     if config.use_syslog:
         wrapper.setup_syslog(execname,