/tmp with noexec fix

Adds option to specify tmp folder prefix and also defines a
default tmp folder outside of /tmp.

There's also a new validation that makes sure that scripts
are executable.

Change-Id: Icc568d0750826b2da24e7fa3bfa6def0fb151209
Closes-Bug: #1796220

instack/main.py

@@ -69,6 +69,10 @@ def load_args(argv):
     parser.add_argument(
         '--no-cleanup', action='store_true',
         help=("Do not cleanup tmp directories"))
+    parser.add_argument(
+        '--tmp-folder', action='store', type=str,
+        default=os.path.join(os.path.expanduser('~'), '.instack/tmp'),
+        help=("Temporary folder prefix"))
     parser.add_argument(
         '-l', '--logfile', action='store',
         default=os.path.join(os.path.expanduser('~'), '.instack/instack.log'),
@@ -131,7 +135,14 @@ def cleanup(tmp_dir):
 def main(argv=sys.argv):
     args = load_args(argv[1:])
 
-    tmp_dir = tempfile.mkdtemp(prefix='instack.')
+    try:
+        os.makedirs(args.tmp_folder)
+    except OSError as e:
+        if e.errno != errno.EEXIST:
+            raise
+
+    tmp_dir = tempfile.mkdtemp(prefix=os.path.join(args.tmp_folder,
+                                                   'instack.'))
     try:
         os.makedirs(os.path.dirname(args.logfile))
     except OSError as e:
@@ -164,13 +175,13 @@ def main(argv=sys.argv):
                 if "name" in run:
                     LOG.info("Running %s" % run["name"])
                 em = runner.ElementRunner(
-                    run['element'], run['hook'], args.element_path,
+                    run['element'], run['hook'], tmp_dir, args.element_path,
                     run.get('blacklist', []), run.get('exclude-element', []),
                     args.dry_run, args.interactive, args.no_cleanup)
                 em.run()
         else:
             em = runner.ElementRunner(
-                args.element, args.hook, args.element_path,
+                args.element, args.hook, tmp_dir, args.element_path,
                 args.blacklist, args.exclude_element,
                 args.dry_run, args.interactive,
                 args.no_cleanup)

instack/runner.py

@@ -44,9 +44,9 @@ LOG = logging.getLogger()
 
 class ElementRunner(object):
 
-    def __init__(self, elements, hooks, element_paths=None, blacklist=None,
-                 exclude_elements=None, dry_run=False, interactive=False,
-                 no_cleanup=False):
+    def __init__(self, elements, hooks, tmp_folder, element_paths=None,
+                 blacklist=None, exclude_elements=None, dry_run=False,
+                 interactive=False, no_cleanup=False):
         """Element Runner initialization.
 
         :param elements: Element names to apply.
@@ -66,7 +66,8 @@ class ElementRunner(object):
         self.interactive = interactive
         self.no_cleanup = no_cleanup
         self.loaded_elements = {}
-        self.tmp_hook_dir = tempfile.mkdtemp()
+        self.tmp_hook_dir = tempfile.mkdtemp(prefix='hook',
+                                             dir=''.join(tmp_folder))
         self.environment_file = os.path.join(self.tmp_hook_dir,
                                              'environment.d',
                                              '00-dib-v2-env')
@@ -192,10 +193,14 @@ class ElementRunner(object):
                      "exist at %s" % (hook, hook_dir))
             return
 
-        for blacklisted_script in self.blacklist:
-            if blacklisted_script in os.listdir(hook_dir):
-                LOG.debug("    Blacklisting %s" % blacklisted_script)
-                os.unlink(os.path.join(hook_dir, blacklisted_script))
+        for script in os.listdir(hook_dir):
+            script_fullpath = os.path.join(hook_dir, script)
+            if script in self.blacklist:
+                LOG.debug("    Blacklisting %s" % script)
+                os.unlink(script_fullpath)
+
+            if not os.access(script_fullpath, os.X_OK):
+                LOG.debug("Script %s not executable" % script)
 
         command = [_DIB_RUN_PARTS, hook_dir]
         if self.dry_run:

instack/tests/test_runner.py

@@ -36,7 +36,7 @@ class TestRunner(testtools.TestCase):
                                          'generate_environment')
         self.mock_env = self.patcher.start()
         self.runner = runner.ElementRunner(['dep2', 'echo', 'os'], [],
-                                           self.element_paths)
+                                           '/tmp', self.element_paths)
         tmp_dir = tempfile.mkdtemp()
         self.runner.tmp_hook_dir = tmp_dir