Disable command run under root user

Running openstack command with python-tripleoclient under
root user is not supported and should not be allowed. Added
check for user and exit if it is root (EUID=0) to openstack
undercloud install command.

Each command can be disabled for root by adding
utils.ensure_run_as_normal_user() into it's body.

Change-Id: I685c639e02790483d1607c7eac038f8b9b8dc99e
Closes-Bug: rhbz#1239088

tripleoclient/exceptions.py

@@ -39,3 +39,8 @@ class NotFound(Exception):
 class DeploymentError(Exception):
     """Deployment failed"""
     pass
+
+
+class RootUserExecution(Exception):
+    """Command was executed by a root user"""
+    pass

tripleoclient/tests/test_utils.py

@@ -413,3 +413,17 @@ class TestCheckNodesCount(TestCase):
 
         self.assertRaises(ValueError, utils.check_nodes_count,
                           self.baremetal, self.stack, dict(), self.defaults)
+
+
+class TestEnsureRunAsNormalUser(TestCase):
+
+    @mock.patch('os.geteuid')
+    def test_ensure_run_as_normal_user(self, os_geteuid_mock):
+        os_geteuid_mock.return_value = 1000
+        self.assertEqual(utils.ensure_run_as_normal_user(), None)
+
+    @mock.patch('os.geteuid')
+    def test_ensure_run_as_normal_user_root(self, os_geteuid_mock):
+        os_geteuid_mock.return_value = 0
+        self.assertRaises(exceptions.RootUserExecution,
+                          utils.ensure_run_as_normal_user)

tripleoclient/utils.py

@@ -518,3 +518,11 @@ def check_nodes_count(baremetal_client, stack, parameters, defaults):
                 ironic_nodes_count, count))
     else:
         return True
+
+
+def ensure_run_as_normal_user():
+    """Check if the command runs under normal user (EUID!=0)"""
+    if os.geteuid() == 0:
+        raise exceptions.RootUserExecution(
+            'This command cannot run under root user.'
+            ' Switch to a normal user.')

tripleoclient/v1/undercloud.py

@@ -19,6 +19,7 @@ import logging
 import subprocess
 
 from cliff import command
+from tripleoclient import utils
 
 
 class InstallPlugin(command.Command):
@@ -30,6 +31,8 @@ class InstallPlugin(command.Command):
     def take_action(self, parsed_args):
         self.log.debug("take_action(%s)" % parsed_args)
 
+        utils.ensure_run_as_normal_user()
+
         subprocess.check_call("instack-install-undercloud")
 
         return