DataSourceOracle: refactor to use only OPC v1 endpoint (#493)

The /opc/v1/ metadata endpoints[0] are universally available in Oracle
Cloud Infrastructure and the OpenStack endpoints are considered
deprecated, so we can refactor the data source to use the OPC endpoints
exclusively.  This simplifies the datasource code substantially, and
enables use of OPC-specific attributes in future.

[0] https://docs.cloud.oracle.com/en-us/iaas/Content/Compute/Tasks/gettingmetadata.htm

1 files changed, 102 insertions, 14 deletions

diff --git a/conftest.py b/conftest.py
index faf13804..76e9000a 100644
--- a/conftest.py
+++ b/conftest.py
@@ -1,24 +1,64 @@
+import os
 from unittest import mock
 
 import pytest
+import httpretty as _httpretty
 
-from cloudinit import subp
+from cloudinit import helpers, subp
 
 
-def _closest_marker_args_or(request, marker_name: str, default):
-    """Get the args for the closest ``marker_name`` or return ``default``"""
-    try:
-        marker = request.node.get_closest_marker(marker_name)
-    except AttributeError:
-        # Older versions of pytest don't have the new API
-        marker = request.node.get_marker(marker_name)
-    if marker is not None:
-        return marker.args
-    return default
+class _FixtureUtils:
+    """A namespace for fixture helper functions, used by fixture_utils.
+
+    These helper functions are all defined as staticmethods so they are
+    effectively functions; they are defined in a class only to give us a
+    namespace so calling them can look like
+    ``fixture_utils.fixture_util_function()`` in test code.
+    """
+
+    @staticmethod
+    def closest_marker_args_or(request, marker_name: str, default):
+        """Get the args for closest ``marker_name`` or return ``default``
+
+        :param request:
+            A pytest request, as passed to a fixture.
+        :param marker_name:
+            The name of the marker to look for
+        :param default:
+            The value to return if ``marker_name`` is not found.
+
+        :return:
+            The args for the closest ``marker_name`` marker, or ``default``
+            if no such marker is found.
+        """
+        try:
+            marker = request.node.get_closest_marker(marker_name)
+        except AttributeError:
+            # Older versions of pytest don't have the new API
+            marker = request.node.get_marker(marker_name)
+        if marker is not None:
+            return marker.args
+        return default
+
+    @staticmethod
+    def closest_marker_first_arg_or(request, marker_name: str, default):
+        """Get the first arg for closest ``marker_name`` or return ``default``
+
+        This is a convenience wrapper around closest_marker_args_or, see there
+        for full details.
+        """
+        result = _FixtureUtils.closest_marker_args_or(
+            request, marker_name, [default]
+        )
+        if not result:
+            raise TypeError(
+                "Missing expected argument to {} marker".format(marker_name)
+            )
+        return result[0]
 
 
 @pytest.yield_fixture(autouse=True)
-def disable_subp_usage(request):
+def disable_subp_usage(request, fixture_utils):
     """
     Across all (pytest) tests, ensure that subp.subp is not invoked.
 
@@ -53,10 +93,14 @@ def disable_subp_usage(request):
     tests, CiTestCase's allowed_subp does take precedence (and we have
     TestDisableSubpUsageInTestSubclass to confirm that).
     """
-    allow_subp_for = _closest_marker_args_or(request, "allow_subp_for", None)
+    allow_subp_for = fixture_utils.closest_marker_args_or(
+        request, "allow_subp_for", None
+    )
     # Because the mark doesn't take arguments, `allow_all_subp` will be set to
     # [] if the marker is present, so explicit None checks are required
-    allow_all_subp = _closest_marker_args_or(request, "allow_all_subp", None)
+    allow_all_subp = fixture_utils.closest_marker_args_or(
+        request, "allow_all_subp", None
+    )
 
     if allow_all_subp is not None and allow_subp_for is None:
         # Only allow_all_subp specified, don't mock subp.subp
@@ -93,3 +137,47 @@ def disable_subp_usage(request):
     with mock.patch("cloudinit.subp.subp", autospec=True) as m_subp:
         m_subp.side_effect = side_effect
         yield
+
+
+@pytest.fixture(scope="session")
+def fixture_utils():
+    """Return a namespace containing fixture utility functions.
+
+    See :py:class:`_FixtureUtils` for further details."""
+    return _FixtureUtils
+
+
+@pytest.yield_fixture
+def httpretty():
+    """
+    Enable HTTPretty for duration of the testcase, resetting before and after.
+
+    This will also ensure allow_net_connect is set to False, and temporarily
+    unset http_proxy in os.environ if present (to work around
+    https://github.com/gabrielfalcao/HTTPretty/issues/122).
+    """
+    restore_proxy = os.environ.pop("http_proxy", None)
+    _httpretty.HTTPretty.allow_net_connect = False
+    _httpretty.reset()
+    _httpretty.enable()
+
+    yield _httpretty
+
+    _httpretty.disable()
+    _httpretty.reset()
+    if restore_proxy is not None:
+        os.environ["http_proxy"] = restore_proxy
+
+
+@pytest.fixture
+def paths(tmpdir):
+    """
+    Return a helpers.Paths object configured to use a tmpdir.
+
+    (This uses the builtin tmpdir fixture.)
+    """
+    dirs = {
+        "cloud_dir": tmpdir.mkdir("cloud_dir").strpath,
+        "run_dir": tmpdir.mkdir("run_dir").strpath,
+    }
+    return helpers.Paths(dirs)