Add ringbuilder tests for --yes option

Also added a Timeout class to test.unit to wrap possible long-running
functions. For example, if there is some regression and the "--yes"
argument is no longer evaluated correctly and the test excepts some
keyboard input, it will be terminated after a few seconds to ensure
there is no long-running blocker on the gate.

Change-Id: I07b17d21d5af7fcc594ce5319ae2b6f7f58df4bb

test/unit/__init__.py

@@ -32,6 +32,7 @@ import eventlet
 from eventlet.green import socket
 from tempfile import mkdtemp
 from shutil import rmtree
+import signal
 import json
 
 
@@ -1061,3 +1062,20 @@ def mocked_http_conn(*args, **kwargs):
 
 def make_timestamp_iter():
     return iter(Timestamp(t) for t in itertools.count(int(time.time())))
+
+
+class Timeout(object):
+    def __init__(self, seconds):
+        self.seconds = seconds
+
+    def __enter__(self):
+        signal.signal(signal.SIGALRM, self._exit)
+        signal.alarm(self.seconds)
+
+    def __exit__(self, type, value, traceback):
+        signal.alarm(0)
+
+    def _exit(self, signum, frame):
+        class TimeoutException(Exception):
+            pass
+        raise TimeoutException

test/unit/cli/test_ringbuilder.py

@@ -29,6 +29,8 @@ from swift.cli.ringbuilder import EXIT_SUCCESS, EXIT_WARNING, EXIT_ERROR
 from swift.common import exceptions
 from swift.common.ring import RingBuilder
 
+from test.unit import Timeout
+
 
 class RunSwiftRingBuilderMixin(object):
 
@@ -1955,6 +1957,29 @@ class TestCommands(unittest.TestCase, RunSwiftRingBuilderMixin):
         argv = ["-safe", self.tmpfile]
         self.assertSystemExit(EXIT_SUCCESS, ringbuilder.main, argv)
 
+    def test_remove_all_devices(self):
+        # Would block without the 'yes' argument
+        self.create_sample_ring()
+        argv = ["", self.tmpfile, "remove", "--weight", "100", "--yes"]
+        with Timeout(5):
+            self.assertSystemExit(EXIT_SUCCESS, ringbuilder.main, argv)
+
+    def test_set_info_all_devices(self):
+        # Would block without the 'yes' argument
+        self.create_sample_ring()
+        argv = ["", self.tmpfile, "set_info", "--weight", "100",
+                "--change-meta", "something", "--yes"]
+        with Timeout(5):
+            self.assertSystemExit(EXIT_SUCCESS, ringbuilder.main, argv)
+
+    def test_set_weight_all_devices(self):
+        # Would block without the 'yes' argument
+        self.create_sample_ring()
+        argv = ["", self.tmpfile, "set_weight",
+                "--weight", "100", "200", "--yes"]
+        with Timeout(5):
+            self.assertSystemExit(EXIT_SUCCESS, ringbuilder.main, argv)
+
 
 class TestRebalanceCommand(unittest.TestCase, RunSwiftRingBuilderMixin):