Add acloud test build target.

Bug: 110430047
Test: m acloud_test && acloud_test
./run_tests.sh
Change-Id: I1d18db2a4363271a1422e3516ee603547b8942e0
diff --git a/acloud_test.py b/acloud_test.py
new file mode 100644
index 0000000..fb8bf05
--- /dev/null
+++ b/acloud_test.py
@@ -0,0 +1,72 @@
+#!/usr/bin/python
+#
+# Copyright 2018 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Main entry point for all of acloud's unittest."""
+
+from importlib import import_module
+import os
+import sys
+import unittest
+
+
+def GetTestModules():
+    """Return list of testable modules.
+
+    We need to find all the test files (*_test.py) and get their relative
+    path (internal/lib/utils_test.py) and translate it to an import path and
+    strip the py ext (internal.lib.utils_test).
+
+    Returns:
+        List of strings (the testable module import path).
+    """
+    testable_modules = []
+    base_path = os.path.dirname(os.path.realpath(__file__))
+
+    # Get list of all python files that end in _test.py (except for __file__).
+    for dirpath, _, files in os.walk(base_path):
+        for f in files:
+            if f.endswith("_test.py") and f != os.path.basename(__file__):
+                # Now transform it into a relative import path.
+                full_file_path = os.path.join(dirpath, f)
+                rel_file_path = os.path.relpath(full_file_path, base_path)
+                rel_file_path, _ = os.path.splitext(rel_file_path)
+                rel_file_path = rel_file_path.replace(os.sep, ".")
+                testable_modules.append(rel_file_path)
+
+    return testable_modules
+
+
+def main(_):
+    """Main unittest entry.
+
+    Args:
+        argv: A list of system arguments. (unused)
+
+    Returns:
+        0 if success. None-zero if fails.
+    """
+    test_modules = GetTestModules()
+    for mod in test_modules:
+        import_module(mod)
+
+    loader = unittest.defaultTestLoader
+    test_suite = loader.loadTestsFromNames(test_modules)
+    runner = unittest.TextTestRunner(verbosity=2)
+    result = runner.run(test_suite)
+    sys.exit(not result.wasSuccessful())
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])