tests/systemd - Add more helpers for cgroup delegation

Add more helpers to work with systemd cgroup delegation, this patch
adds:
- remove_scope_slice_conf() to remove the cgconfig file created and
  remove the scope cgroup and slice cgroups.
- write_config_with_pid() to write a cgconfig file with the systemd
  configurations.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>

diff --git a/tests/ftests/systemd.py b/tests/ftests/systemd.py
index e2388c9d231e7e7da2413ade492a7ff4ed53c5c3..826f3c4032c9ed900bc83cf306b2374e9bee47b8 100644 (file)
--- a/tests/ftests/systemd.py
+++ b/tests/ftests/systemd.py
@@ -7,6 +7,8 @@
 #
 
 from run import Run, RunError
+from cgroup import Cgroup
+import os
 
 
 class Systemd(object):
@@ -27,3 +29,48 @@ class Systemd(object):
                 # until we figure out something better :(
                 return True
             raise re
+
+    # This function creates a task and writes its pid into systemd
+    # configuration file, that gets passed to the cgconfigparser tool to
+    # create systemd slice/scope.
+    @staticmethod
+    def write_config_with_pid(config, config_fname, _slice, scope, setdefault="yes"):
+        pid = config.process.create_process(config)
+        config_file = '''systemd {{
+            slice = {};
+            scope = {};
+            setdefault = {};
+            pid = {};
+        }}'''.format(_slice, scope, setdefault, pid)
+
+        f = open(config_fname, 'w')
+        f.write(config_file)
+        f.close()
+
+        return pid
+
+    # Stopping the systemd scope, will kill the default task in the scope
+    # and remove scope cgroup but will not remove the slice, that needs to
+    # removed manually.
+    @staticmethod
+    def remove_scope_slice_conf(config, _slice, scope, controller, config_fname=None):
+        if config_fname:
+            os.remove(config_fname)
+
+        try:
+            if config.args.container:
+                config.container.run(['systemctl', 'stop', '{}'.format(scope)],
+                                     shell_bool=True)
+            else:
+                Run.run(['sudo', 'systemctl', 'stop', '{}'.format(scope)], shell_bool=True)
+        except RunError as re:
+            if 'scope not loaded' in re.stderr:
+                raise re
+
+        # In case the error occurs before the creation of slice/scope and
+        # we may very well be on the teardown path, ignore the exception
+        try:
+            Cgroup.delete(config, controller, cgname=_slice, ignore_systemd=True)
+        except RunError as re:
+            if 'No such file or directory' not in re.stderr:
+                raise re