Allow freeipa-tests to work with older paramiko versions

The integration testing framework used Paramiko SFTP files as
context managers. This feature is only available in Paramiko 1.10+.
Use an explicit context manager so that we don't rely on the feature.

freeipa.spec.in

@@ -304,7 +304,7 @@ Requires: python-nose
 Requires: python-paste
 Requires: python-coverage
 Requires: python-polib
-Requires: python-paramiko >= 1.10.1
+Requires: python-paramiko >= 1.7.7
 
 %description tests
 IPA is an integrated solution to provide centrally managed Identity (machine,
@@ -833,6 +833,9 @@ fi
 %endif # ONLY_CLIENT
 
 %changelog
+* Mon Aug 12 2013 Petr Viktorin <pviktori@redhat.com> - 3.3.90-1
+- Downgrade required version of python-paramiko for the tests subpackage
+
 * Thu Aug 8 2013 Martin Kosek <mkosek@redhat.com> - 3.2.99-13
 - Require slapi-nis 0.47.7 and sssd 1.11.0-0.1.beta2 required for core
   features of 3.3.0 release

ipatests/test_integration/host.py

@@ -23,6 +23,7 @@ import os
 import socket
 import threading
 import subprocess
+from contextlib import contextmanager
 import errno
 
 import paramiko
@@ -118,6 +119,21 @@ class RemoteCommand(object):
         return thread
 
 
+@contextmanager
+def sftp_open(sftp, filename, mode='r'):
+    """Context manager that provides a file-like object over a SFTP channel
+
+    This provides compatibility with older Paramiko versions.
+    (In Paramiko 1.10+, file objects from `sftp.open` are directly usable as
+    context managers).
+    """
+    file = sftp.open(filename, mode)
+    try:
+        yield file
+    finally:
+        file.close()
+
+
 class Host(object):
     """Representation of a remote IPA host"""
     def __init__(self, domain, hostname, role, index, ip=None):
@@ -314,13 +330,13 @@ class Host(object):
     def get_file_contents(self, filename):
         """Read the named remote file and return the contents as a string"""
         self.log.debug('READ %s', filename)
-        with self.sftp.open(filename) as f:
+        with sftp_open(self.sftp, filename) as f:
             return f.read()
 
     def put_file_contents(self, filename, contents):
         """Write the given string to the named remote file"""
         self.log.info('WRITE %s', filename)
-        with self.sftp.open(filename, 'w') as f:
+        with sftp_open(self.sftp, filename, 'w') as f:
             f.write(contents)
 
     def file_exists(self, filename):