ipatests: fix modify_sssd_conf()

The method modify_sssd_conf() is copying a remote sssd.conf file
to the test controller then uses sssd python API to modify the
config file.
When the test controller does not have sssd-common package installed,
SSSDConfig() call fails because the API needs sssd schema in order
to properly parse the config file, and the schema files are provided
by sssd-common pkg.
The fix also downloads the files representing sssd schema and calls
SSSDConfig() with those files. Using the schema from the test machine
is ensuring that config is consistent with the schema (if the sssd
version differs between controller and test machine for instance).

Note: we currently don't see any issue in the nightly tests because
the test controller is installed with sssd-common package but if you
run the tests as specified in https://www.freeipa.org/page/Testing
with a controller missing sssd-common, you will see the issue.

Reviewed-By: Sergey Orlov <sorlov@redhat.com>

ipatests/pytest_ipa/integration/tasks.py

@@ -28,6 +28,7 @@ import textwrap
 import re
 import collections
 import itertools
+import shutil
 import tempfile
 import time
 from pipes import quote
@@ -820,7 +821,30 @@ def modify_sssd_conf(host, domain, mod_dict, provider='ipa',
         with open(temp_config_file, 'wb') as f:
             f.write(current_config)
 
-        sssd_config = SSSDConfig()
+        # In order to use SSSDConfig() locally we need to import the schema
+        # Create a tar file with /usr/share/sssd.api.conf and
+        # /usr/share/sssd/sssd.api.d
+        tmpname = create_temp_file(host)
+        host.run_command(
+            ['tar', 'cJvf', tmpname,
+             'sssd.api.conf',
+             'sssd.api.d'],
+            log_stdout=False, cwd="/usr/share/sssd")
+        # fetch tar file
+        tar_dir = tempfile.mkdtemp()
+        tarname = os.path.join(tar_dir, "sssd_schema.tar.xz")
+        with open(tarname, 'wb') as f:
+            f.write(host.get_file_contents(tmpname))
+        # delete from remote
+        host.run_command(['rm', '-f', tmpname])
+        # Unpack on the local side
+        ipautil.run([paths.TAR, 'xJvf', tarname], cwd=tar_dir)
+        os.unlink(tarname)
+
+        # Use the imported schema
+        sssd_config = SSSDConfig(
+            schemafile=os.path.join(tar_dir, "sssd.api.conf"),
+            schemaplugindir=os.path.join(tar_dir, "sssd.api.d"))
         sssd_config.import_config(temp_config_file)
         sssd_domain = sssd_config.get_domain(domain)
 
@@ -837,6 +861,7 @@ def modify_sssd_conf(host, domain, mod_dict, provider='ipa',
     finally:
         try:
             os.remove(temp_config_file)
+            shutil.rmtree(tar_dir)
         except OSError:
             pass