ftests: Add a test for unmappable settings

-----------------------------------------------------------------
Test Results:
        Run Date:                          Feb 02 17:47:50
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                         Time (sec)
        ---------------------------------------
        setup                              0.00
        042-cgxget-unmappable.py           0.19
        teardown                           0.00
        ---------------------------------------
        Total Run Time                     0.19

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>

diff --git a/ftests/042-cgxget-unmappable.py b/ftests/042-cgxget-unmappable.py
new file mode 100755 (executable)
index 0000000..0c48247
--- /dev/null
+++ b/ftests/042-cgxget-unmappable.py
@@ -0,0 +1,79 @@
+#!/usr/bin/env python3
+#
+# Cgxget test with no mappable settings
+#
+# Copyright (c) 2022 Oracle and/or its affiliates.
+# Author: Tom Hromatka <tom.hromatka@oracle.com>
+#
+
+#
+# This library is free software; you can redistribute it and/or modify it
+# under the terms of version 2.1 of the GNU Lesser General Public License as
+# published by the Free Software Foundation.
+#
+# This library is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+# for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this library; if not, see <http://www.gnu.org/licenses>.
+#
+
+from cgroup import Cgroup, CgroupVersion
+import consts
+import ftests
+import os
+import sys
+
+CONTROLLER = 'cpu'
+CGNAME = '042cgxget'
+SETTING = 'cpu.stat'
+
+def prereqs(config):
+    result = consts.TEST_PASSED
+    cause = None
+
+    return result, cause
+
+def setup(config):
+    Cgroup.create(config, CONTROLLER, CGNAME)
+
+def test(config):
+    result = consts.TEST_PASSED
+    cause = None
+
+    if CgroupVersion.get_version(CONTROLLER) == CgroupVersion.CGROUP_V1:
+        # request the opposite version of what this system is running
+        requested_ver = CgroupVersion.CGROUP_V2
+    else:
+        requested_ver = CgroupVersion.CGROUP_V1
+
+    out = Cgroup.xget(config, cgname=CGNAME, setting=SETTING,
+                      version=requested_ver, print_headers=False,
+                      ignore_unmappable=True)
+    if len(out):
+        result = consts.TEST_FAILED
+        cause = "Expected cgxget to return nothing.  Received {}".format(out)
+
+    return result, cause
+
+def teardown(config):
+    Cgroup.delete(config, CONTROLLER, CGNAME)
+
+def main(config):
+    [result, cause] = prereqs(config)
+    if result != consts.TEST_PASSED:
+        return [result, cause]
+
+    setup(config)
+    [result, cause] = test(config)
+    teardown(config)
+
+    return [result, cause]
+
+if __name__ == '__main__':
+    config = ftests.parse_args()
+    # this test was invoked directly.  run only it
+    config.args.num = int(os.path.basename(__file__).split('-')[0])
+    sys.exit(ftests.main(config))