Add unit test checking no hanging procs present

This patch adds a simple unit test checking that if a tarantool server
failed to start within a certain amount of seconds, test-tun raises a
comprehensible exception and kills the server process.

Follows up #256
Follows up #276

Author: ylobankov

.luacheckrc

@@ -27,6 +27,7 @@ include_files = {
 exclude_files = {
     "lib/tarantool-python",
     "test/test-tarantool/*.test.lua",
+    "test/unittest/*.test.lua",
     "lib/luatest/**",
     "lib/checks/**",
 }

Makefile

@@ -15,7 +15,7 @@ luacheck:
 	luacheck --config .luacheckrc .
 
 test_integration:
-	PYTHONPATH=$(PROJECT_DIR) $(PYTHON) test/test-run.py --force $(TEST_RUN_EXTRA_PARAMS)
+	PYTHONPATH=$(PROJECT_DIR) $(PYTHON) test/test-run.py --force --exclude unittest $(TEST_RUN_EXTRA_PARAMS)
 
 test_unittest:
 	$(PYTHON) -m unittest discover test/unittest/

test/unittest/box-cc0544b6afd1.lua

@@ -0,0 +1,7 @@
+#!/usr/bin/env tarantool
+
+box.cfg {
+    listen = os.getenv('LISTEN'),
+}
+
+require('console').listen(os.getenv('ADMIN'))

test/unittest/hang.result

@@ -0,0 +1,6 @@
+test_run = require('test_run').new()
+
+-- This test should hang: we are unable to bootstrap the replica, because it is
+-- unable to join the master because of lack of granting user permissions.
+test_run:cmd('create server replica with rpl_master=default, script="unittest/replica-7f4d4895ff58.lua"')
+test_run:cmd('start server replica')

test/unittest/hang.test.lua

@@ -0,0 +1,8 @@
+#!/usr/bin/env tarantool
+
+box.cfg {
+    listen = os.getenv('LISTEN'),
+    replication = os.getenv('MASTER'),
+}
+
+require('console').listen(os.getenv('ADMIN'))

test/unittest/replica-7f4d4895ff58.lua

@@ -0,0 +1,6 @@
+[default]
+core = tarantool
+description = unit tests
+script = box-cc0544b6afd1.lua
+use_unix_sockets = True
+use_unix_sockets_iproto = True

test/unittest/suite.ini

@@ -0,0 +1,47 @@
+import os
+import subprocess
+import sys
+import unittest
+
+
+class TestTarantoolServer(unittest.TestCase):
+    def test_tarantool_server_not_hanging(self):
+        env = os.environ.copy()
+        env['SERVER_START_TIMEOUT'] = '5'
+
+        cmd = [sys.executable, 'test/test-run.py', 'unittest/hang.test.lua']
+
+        # File names intentionally have hashes to find exactly these processes
+        # using 'ps' command.
+        box_instance = 'box-cc0544b6afd1'
+        replica_instance = 'replica-7f4d4895ff58'
+
+        err_msg_1 = ('[Instance "%s"] Failed to start tarantool '
+                     'instance "%s"' % (box_instance, replica_instance))
+        err_msg_2 = ('[Instance "%s"] Failed to start within %s seconds'
+                     % (replica_instance, env['SERVER_START_TIMEOUT']))
+
+        try:
+            subprocess.check_output(cmd, env=env, universal_newlines=True)
+            self.fail("Command `%s` did not return non-zero exit code"
+                      % ' '.join(cmd))
+        except subprocess.CalledProcessError as exc:
+            err_obj = exc
+
+        self.assertIn(err_msg_1, err_obj.output)
+        self.assertIn(err_msg_2, err_obj.output)
+
+        ps_lines = subprocess.check_output(
+            ['ps', '-o', 'command'], universal_newlines=True
+        ).splitlines()
+        proc_lines = [line.strip() for line in ps_lines
+                      if 'tarantool %s.lua' % box_instance in line or
+                      'tarantool %s.lua' % replica_instance in line]
+
+        self.assertFalse(
+            proc_lines, 'There are some hanging tarantool processes!'
+        )
+
+
+if __name__ == '__main__':
+    unittest.main()