ftests: Add cgset --copy-from test

Add a test that utilizes the cgset --copy-from flag.

-----------------------------------------------------------------
Test Results:
        Run Date:                          Mar 02 20:24:45
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                                    Time (sec)
        ---------------------------------------------------------
        setup                                        22.79
        023-cgset-copy_from.py                        1.13
        teardown                                      0.00
        ---------------------------------------------------------
        Total Run Time                               23.93

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

diff --git a/ftests/023-cgset-copy_from.py b/ftests/023-cgset-copy_from.py
new file mode 100755 (executable)
index 0000000..03c9b6d
--- /dev/null
+++ b/ftests/023-cgset-copy_from.py
@@ -0,0 +1,91 @@
+#!/usr/bin/env python3
+#
+# Advanced cgset functionality test - test the '--copy-from' option
+#
+# Copyright (c) 2021 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 = 'memory'
+SRC_CGNAME = '023cgsetsrc'
+DST_CGNAME = '023cgsetdst'
+
+SETTINGS = ['memory.limit_in_bytes',
+            'memory.soft_limit_in_bytes',
+            'memory.swappiness']
+VALUES = ['122880', '40960', '42']
+
+def prereqs(config):
+    result = consts.TEST_PASSED
+    cause = None
+
+    if CgroupVersion.get_version('memory') != CgroupVersion.CGROUP_V1:
+        result = consts.TEST_SKIPPED
+        cause = "This test requires the cgroup v1 memory controller"
+        return result, cause
+
+    return result, cause
+
+def setup(config):
+    Cgroup.create(config, CONTROLLER, SRC_CGNAME)
+    Cgroup.create(config, CONTROLLER, DST_CGNAME)
+    Cgroup.set(config, cgname=SRC_CGNAME, setting=SETTINGS, value=VALUES)
+
+def test(config):
+    result = consts.TEST_PASSED
+    cause = None
+
+    Cgroup.set(config, cgname=DST_CGNAME, copy_from=SRC_CGNAME)
+
+    for i, setting in enumerate(SETTINGS):
+        value = Cgroup.get(config, cgname=DST_CGNAME, setting=setting,
+                           print_headers=False, values_only=True)
+
+        if value != VALUES[i]:
+            result = consts.TEST_FAILED
+            cause = "Expected {} to be set to {}, but received {}".format(
+                    setting, VALUES[i], value)
+            return result, cause
+
+    return result, cause
+
+def teardown(config):
+    Cgroup.delete(config, CONTROLLER, SRC_CGNAME)
+    Cgroup.delete(config, CONTROLLER, DST_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))