feat(cloud): Handle cloud testing errors

Cloud test framework can run into errors (like SSH connection drops)
which cause it to error out and not report test results. To handle these
kinds of errors the policy now checks the return code and stores
std_err.

Also updates the test already run check to not count states of zero
failures and non-zero errors; since this means the test framework
encountered an error external to the tests.

britney2/policies/cloud.py

@@ -155,6 +155,9 @@ class CloudPolicy(BasePolicy):
         """Check if tests were already run for the given package version.
         This takes which cloud we're testing into consideration.
 
+        If failures=0 and errors>0 then tests are considered to have not ran because
+        of previous test errors.
+
         :param package The name of the package to test
         :param version Version of the package
         :param series The Ubuntu codename for the series (e.g. jammy)
@@ -162,7 +165,11 @@ class CloudPolicy(BasePolicy):
         :param cloud The name of the cloud being tested (e.g. azure)
         """
         try:
-            return self.state[cloud][source_type][series][package]["version"] == version
+            package_state = self.state[cloud][source_type][series][package]
+            same_version = package_state["version"] == version
+            only_errors = package_state["failures"] == 0 and package_state["errors"] > 0
+
+            return same_version and not only_errors
         except KeyError:
             return False
 
@@ -258,6 +265,7 @@ class CloudPolicy(BasePolicy):
         """
         if self._check_if_tests_run(package, version, series, source_type, "azure"):
             self._set_previous_failure_and_error(package, version, series, source_type, "azure")
+            self.logger.info("Cloud Policy: already tested {}".format(package))
             return
 
         urn = self._retrieve_urn(series)
@@ -278,17 +286,26 @@ class CloudPolicy(BasePolicy):
             ]
         )
 
-        with open(PurePath(self.work_dir, self.TEST_LOG_FILE), "w") as file:
-            subprocess.run(
-                params,
-                cwd=self.work_dir,
-                stdout=file
+        result = None
+        try:
+            with open(PurePath(self.work_dir, self.TEST_LOG_FILE), "w") as file:
+                result = subprocess.run(
+                    params,
+                    cwd=self.work_dir,
+                    stdout=file,
+                    stderr=subprocess.PIPE,
+                    text=True
+                )
+                result.check_returncode()
+        except subprocess.CalledProcessError:
+            self._store_test_result(
+                self.errors, "azure", "testing_error", result.stderr
             )
-
-        results_file_paths = self._find_results_files(r"TEST-NetworkTests-[0-9]*.xml")
-        self._parse_xunit_test_results("Azure", results_file_paths)
-        self._store_extra_test_result_info(self, package)
-        self._mark_tests_run(package, version, series, source_type, "azure")
+        finally:
+            results_file_paths = self._find_results_files(r"TEST-NetworkTests-[0-9]*.xml")
+            self._parse_xunit_test_results("Azure", results_file_paths)
+            self._store_extra_test_result_info(self, package)
+            self._mark_tests_run(package, version, series, source_type, "azure")
 
     def _retrieve_urn(self, series):
         """Retrieves an URN from the configuration options based on series.