Reorganize unit test locations under tests/unittests (#1126)

This attempts to standardize unit test file location under test/unittests/
such that any source file located at cloudinit/path/to/file.py may have a
corresponding unit test file at test/unittests/path/to/test_file.py.

Noteworthy Comments:
====================
Four different duplicate test files existed:
test_{gpg,util,cc_mounts,cc_resolv_conf}.py
Each of these duplicate file pairs has been merged together. This is a
break in git history for these files.

The test suite appears to have a dependency on test order. Changing test
order causes some tests to fail. This should be rectified, but for now
some tests have been modified in
tests/unittests/config/test_set_passwords.py.

A helper class name starts with "Test" which causes pytest to try
executing it as a test case, which then throws warnings "due to Class
having __init__()".  Silence by changing the name of the class.

# helpers.py is imported in many test files, import paths change
cloudinit/tests/helpers.py -> tests/unittests/helpers.py

# Move directories:
cloudinit/distros/tests -> tests/unittests/distros
cloudinit/cmd/devel/tests -> tests/unittests/cmd/devel
cloudinit/cmd/tests -> tests/unittests/cmd/
cloudinit/sources/helpers/tests -> tests/unittests/sources/helpers
cloudinit/sources/tests -> tests/unittests/sources
cloudinit/net/tests -> tests/unittests/net
cloudinit/config/tests -> tests/unittests/config
cloudinit/analyze/tests/ -> tests/unittests/analyze/

# Standardize tests already in tests/unittests/
test_datasource -> sources
test_distros -> distros
test_vmware -> sources/vmware
test_handler -> config        # this contains cloudconfig module tests
test_runs -> runs

1 files changed, 65 insertions, 0 deletions

diff --git a/tests/unittests/test_conftest.py b/tests/unittests/test_conftest.py
new file mode 100644
index 00000000..2e02b7a7
--- /dev/null
+++ b/tests/unittests/test_conftest.py
@@ -0,0 +1,65 @@
+import pytest
+
+from cloudinit import subp
+from tests.unittests.helpers import CiTestCase
+
+
+class TestDisableSubpUsage:
+    """Test that the disable_subp_usage fixture behaves as expected."""
+
+    def test_using_subp_raises_assertion_error(self):
+        with pytest.raises(AssertionError):
+            subp.subp(["some", "args"])
+
+    def test_typeerrors_on_incorrect_usage(self):
+        with pytest.raises(TypeError):
+            # We are intentionally passing no value for a parameter, so:
+            #  pylint: disable=no-value-for-parameter
+            subp.subp()
+
+    @pytest.mark.allow_all_subp
+    def test_subp_usage_can_be_reenabled(self):
+        subp.subp(['whoami'])
+
+    @pytest.mark.allow_subp_for("whoami")
+    def test_subp_usage_can_be_conditionally_reenabled(self):
+        # The two parameters test each potential invocation with a single
+        # argument
+        with pytest.raises(AssertionError) as excinfo:
+            subp.subp(["some", "args"])
+        assert "allowed: whoami" in str(excinfo.value)
+        subp.subp(['whoami'])
+
+    @pytest.mark.allow_subp_for("whoami", "bash")
+    def test_subp_usage_can_be_conditionally_reenabled_for_multiple_cmds(self):
+        with pytest.raises(AssertionError) as excinfo:
+            subp.subp(["some", "args"])
+        assert "allowed: whoami,bash" in str(excinfo.value)
+        subp.subp(['bash', '-c', 'true'])
+        subp.subp(['whoami'])
+
+    @pytest.mark.allow_all_subp
+    @pytest.mark.allow_subp_for("bash")
+    def test_both_marks_raise_an_error(self):
+        with pytest.raises(AssertionError, match="marked both"):
+            subp.subp(["bash"])
+
+
+class TestDisableSubpUsageInTestSubclass(CiTestCase):
+    """Test that disable_subp_usage doesn't impact CiTestCase's subp logic."""
+
+    def test_using_subp_raises_exception(self):
+        with pytest.raises(Exception):
+            subp.subp(["some", "args"])
+
+    def test_typeerrors_on_incorrect_usage(self):
+        with pytest.raises(TypeError):
+            subp.subp()
+
+    def test_subp_usage_can_be_reenabled(self):
+        _old_allowed_subp = self.allow_subp
+        self.allowed_subp = True
+        try:
+            subp.subp(['bash', '-c', 'true'])
+        finally:
+            self.allowed_subp = _old_allowed_subp