create module tmpdir based on remote_tmp (#39833)

* create module tmpdir based on remote_tmp

* Source remote_tmp from controller if possible

* Fixed sanity test and not use lambda

* Added expansion of env vars to the remote tmp

* Fixed sanity issues

* Added note around shell remote_tmp option

* Changed fallback tmp dir to ~/.ansible/tmp to make shell defaults

test/units/module_utils/basic/test_tmpdir.py

@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+# Copyright (c) 2018 Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division)
+__metaclass__ = type
+
+import os
+import shutil
+import tempfile
+
+import pytest
+
+from ansible.compat.tests.mock import patch
+
+
+class TestAnsibleModuleTmpDir:
+
+    DATA = (
+        (
+            {
+                "_ansible_tmpdir": "/path/to/dir",
+                "_ansible_remote_tmp": "/path/tmpdir",
+                "_ansible_keep_remote_files": False,
+            },
+            "/path/to/dir"
+        ),
+        (
+            {
+                "_ansible_tmpdir": None,
+                "_ansible_remote_tmp": "/path/tmpdir",
+                "_ansible_keep_remote_files": False
+            },
+            "/path/tmpdir/ansible-moduletmp-42-"
+        ),
+        (
+            {
+                "_ansible_tmpdir": None,
+                "_ansible_remote_tmp": "$HOME/.test",
+                "_ansible_keep_remote_files": False
+            },
+            os.path.join(os.environ['HOME'], ".test/ansible-moduletmp-42-")
+        ),
+    )
+
+    # pylint bug: https://github.com/PyCQA/pylint/issues/511
+    # pylint: disable=undefined-variable
+    @pytest.mark.parametrize('stdin, expected', ((s, e) for s, e in DATA),
+                             indirect=['stdin'])
+    def test_tmpdir_property(self, am, monkeypatch, expected):
+        def mock_mkdtemp(prefix, dir):
+            return os.path.join(dir, prefix)
+        monkeypatch.setattr(tempfile, 'mkdtemp', mock_mkdtemp)
+        monkeypatch.setattr(shutil, 'rmtree', lambda x: None)
+
+        with patch('time.time', return_value=42):
+            actual_tmpdir = am.tmpdir
+        assert actual_tmpdir == expected
+
+        # verify subsequent calls always produces the same tmpdir
+        assert am.tmpdir == actual_tmpdir