slapos node prune: check running as root according to config

When config specifies root_check=true, check that user is root instead
of probably failing with error messages because some permissions would
be refused.

slapos/cli/prune.py

@@ -32,10 +32,11 @@ import glob
 import os
 import six.moves.configparser as configparser
 
+from slapos.cli.command import check_root_user
 from slapos.cli.config import ConfigCommand
 from slapos.grid.slapgrid import merged_options
 from slapos.grid.utils import setRunning, setFinished
-from slapos.util import rmtree
+from slapos.util import rmtree, string_to_boolean
 
 
 class PruneCommand(ConfigCommand):
@@ -61,6 +62,9 @@ class PruneCommand(ConfigCommand):
       self.app.log.error('No shared_part_list options in slapos config')
       sys.exit(-1)
 
+    if string_to_boolean(options.get('root_check', 'True').lower()):
+      check_root_user(self)
+
     pidfile_software = options.get('pidfile_software')
     if not args.dry_run and pidfile_software and os.path.exists(
         pidfile_software):

slapos/tests/test_cli.py

@@ -404,15 +404,18 @@ class TestCliNode(CliMixin):
     """
     app = slapos.cli.entry.SlapOSApp()
 
-    with patch('slapos.cli.prune.setRunning') as write_pid_file, \
+    with patch('slapos.cli.prune.check_root_user', return_value=True) as checked_root_user, \
+         patch('slapos.cli.prune.setRunning') as write_pid_file, \
          patch('slapos.cli.prune.merged_options', return_value={
             'shared_part_list': 'something',
+            'root_check': 'true',
             'pidfile_software': 'pidfile_software.pid',
          }), \
          patch('slapos.cli.prune.do_prune') as do_prune:
 
       app.run(('node', 'prune'))
 
+      checked_root_user.assert_called_once()
       write_pid_file.assert_called_once_with(
           logger=mock.ANY,
           pidfile='pidfile_software.pid')