exec-test clear testing environment

This commit adds more control over the environment variables in
exec-tests for users. It brings a way how to clear the test environment
during the test runtime so it won't affect the test script. Only thing
which user needs to do is to set the runner.exectest.clear_env to
`system` or `all` in tests config.

Reference: avocado-framework#5889
Signed-off-by: Jan Richter <[email protected]>

avocado/core/__init__.py

@@ -178,6 +178,20 @@ def register_core_options():
         help_msg=help_msg,
     )
 
+    help_msg = (
+        "If and how to clear test environment. Two possible options, "
+        "`system` and `all`. "
+        "`system` = no variables set, besides avocados default and kwargs. "
+        "`all` = only kwargs are set."
+    )
+    stgs.register_option(
+        section="runner.exectest",
+        key="clear_env",
+        key_type=str,
+        default=None,
+        help_msg=help_msg,
+    )
+
     help_msg = (
         "By default Avocado runners will use the {uri} of a test as "
         "its identifier. Use a custom f-string identifier in order to "

avocado/plugins/runners/exec_test.py

@@ -33,7 +33,11 @@ class ExecTestRunner(BaseRunner):
     name = "exec-test"
     description = "Runner for standalone executables treated as tests"
 
-    CONFIGURATION_USED = ["run.keep_tmp", "runner.exectest.exitcodes.skip"]
+    CONFIGURATION_USED = [
+        "run.keep_tmp",
+        "runner.exectest.exitcodes.skip",
+        "runner.exectest.clear_env",
+    ]
 
     def _process_final_status(
         self, process, runnable, stdout=None, stderr=None
@@ -119,15 +123,23 @@ def _is_uri_a_file_on_cwd(uri):
         return False
 
     def _get_env(self, runnable):
-        env = dict(os.environ)
+        clear_env = runnable.config.get("runner.exectest.clear_env", None)
+        if clear_env not in ["all", "system", None]:
+            raise ValueError(
+                f"The `runner.exectest.clear_env` value {clear_env} is not supported."
+            )
+        if clear_env in ["all", "system"]:
+            env = {}
+        else:
+            env = dict(os.environ)
         if runnable.kwargs:
             env.update(runnable.kwargs)
             for key, value in runnable.kwargs.items():
                 if value is None:
                     del env[key]
 
         # set default Avocado environment variables if running on a valid Task
-        if runnable.uri is not None:
+        if runnable.uri is not None and clear_env != "all":
             avocado_test_env_variables = self._get_env_variables(runnable)
             # save environment variables for further cleanup
             runnable.kwargs.update(avocado_test_env_variables)

docs/source/guides/writer/chapters/basics.rst

@@ -99,3 +99,12 @@ disable those variables during the test runtime. To disable a test variable,
 you need to set it in test ``kwargs`` to ``None``  like this::
 
   Runnable("exec-test", "examples/tests/sleeptest.sh", SLEEP_LENGTH=None)
+
+If you need to clear the whole environment before your test, then you can set
+``runner.exectest.clear_env`` config variable. This variable has two options.
+``system`` and ``all``. If you use ``system`` option the testing environment
+will have only Avocado default variables and variables from test ``kwargs``.
+If you use ``all`` option, the testing environment will have only variables
+from test ``kwargs``::
+
+  Runnable("exec-test", "examples/tests/sleeptest.sh", config={'runner.exectest.clear_env': system}, SLEEP_LENGTH=1)

selftests/check.py

@@ -29,7 +29,7 @@
     "nrunner-requirement": 24,
     "unit": 669,
     "jobs": 11,
-    "functional-parallel": 304,
+    "functional-parallel": 306,
     "functional-serial": 6,
     "optional-plugins": 0,
     "optional-plugins-golang": 2,

selftests/functional/basic.py

@@ -104,6 +104,12 @@ def test(self):
 fi
 """
 
+EXEC_DEFAULT_ENV_VARIABLE_TEST = """#!/bin/bash
+if [[ -n "${AVOCADO_VERSION}" ]]; then
+    exit 1
+fi
+"""
+
 
 def probe_binary(binary):
     try:
@@ -1002,6 +1008,24 @@ def setUp(self):
         )
         self.fail_script.save()
 
+    def _test_env(self, configuration, expected_rc, test_file):
+        with script.TemporaryScript("exec_env_var.sh", test_file) as tst:
+            res = process.run(
+                f"env TEST_ENV=test avocado-runner-exec-test runnable-run -k exec-test -u {tst}",
+            )
+            result = res.stdout_text.split("\n")[-2]
+            self.assertIn(
+                "'returncode': 1",
+                result,
+                "Script unexpectedly passed with environment variable set.",
+            )
+
+            res = process.run(
+                f"env TEST_ENV=test avocado-runner-exec-test runnable-run -k exec-test -u {tst} {configuration}"
+            )
+            result = res.stdout_text.split("\n")[-2]
+            self.assertIn(f"'returncode': {expected_rc}", result)
+
     def test_exec_test_pass(self):
         cmd_line = (
             f"{AVOCADO} run --job-results-dir {self.tmpdir.name} "
@@ -1101,24 +1125,21 @@ def test_non_absolute_path(self):
 
     @skipUnlessPathExists("/bin/bash")
     def test_env_var_disable(self):
-        with script.TemporaryScript("exec_env_var.sh", EXEC_ENV_VARIABLE_TEST) as tst:
-            res = process.run(
-                f"env TEST_ENV=test avocado-runner-exec-test runnable-run -k exec-test -u {tst}",
-            )
-            result = res.stdout_text.split("\n")[-2]
-            self.assertIn(
-                "'returncode': 1",
-                result,
-                "Script unexpectedly passed with environment variable set",
-            )
+        self._test_env("TEST_ENV=json:null", 0, EXEC_ENV_VARIABLE_TEST)
 
-            res = process.run(
-                f"env TEST_ENV=test avocado-runner-exec-test runnable-run -k exec-test -u {tst} TEST_ENV=json:null",
-            )
-            result = res.stdout_text.split("\n")[-2]
-            self.assertIn(
-                "'returncode': 0", result, "The env variable was not disabled."
-            )
+    @skipUnlessPathExists("/bin/sh")
+    def test_env_clear_system(self):
+        self._test_env(
+            '-c \'{"runner.exectest.clear_env": "system"}\'', 0, EXEC_ENV_VARIABLE_TEST
+        )
+
+    @skipUnlessPathExists("/bin/sh")
+    def test_env_clear_all(self):
+        self._test_env(
+            '-c \'{"runner.exectest.clear_env": "all"}\'',
+            0,
+            EXEC_DEFAULT_ENV_VARIABLE_TEST,
+        )
 
     def tearDown(self):
         self.pass_script.remove()