From 5a6f95d29eb75cf7d7eea7026cf8b01402f6ede3 Mon Sep 17 00:00:00 2001
From: Jan Richter <jarichte@redhat.com>
Date: Thu, 11 Apr 2024 10:54:39 +0200
Subject: [PATCH] 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 AVOCADO_CLEAR_ENV to `TRUE` in test
`kwargs`.

Reference: #5889
Signed-off-by: Jan Richter <jarichte@redhat.com>
---
 avocado/core/__init__.py                      |  9 +++++++++
 avocado/plugins/runners/exec_test.py          | 12 ++++++++++--
 docs/source/guides/writer/chapters/basics.rst |  7 +++++++
 selftests/check.py                            |  2 +-
 selftests/functional/basic.py                 |  9 +++++++++
 5 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/avocado/core/__init__.py b/avocado/core/__init__.py
index 3120a35dbe..23d02e2b5b 100644
--- a/avocado/core/__init__.py
+++ b/avocado/core/__init__.py
@@ -178,6 +178,15 @@ def register_core_options():
         help_msg=help_msg,
     )
 
+    help_msg = "When this is enabled, avocado will disable all environment variables during exec testing"
+    stgs.register_option(
+        section="runner.exectest",
+        key="clear_env",
+        key_type=bool,
+        default=False,
+        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 "
diff --git a/avocado/plugins/runners/exec_test.py b/avocado/plugins/runners/exec_test.py
index e0fb949b76..37ff282030 100644
--- a/avocado/plugins/runners/exec_test.py
+++ b/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
@@ -119,7 +123,11 @@ 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", False)
+        if clear_env:
+            env = {}
+        else:
+            env = dict(os.environ)
         if runnable.kwargs:
             env.update(runnable.kwargs)
             for key, value in runnable.kwargs.items():
diff --git a/docs/source/guides/writer/chapters/basics.rst b/docs/source/guides/writer/chapters/basics.rst
index eeb479a7db..0f2d47e53d 100644
--- a/docs/source/guides/writer/chapters/basics.rst
+++ b/docs/source/guides/writer/chapters/basics.rst
@@ -99,3 +99,10 @@ disable those variables during the test runtime. To disable the 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 to `True`. When this variable is set, avocado will clear
+the entire environment during the test runtime and keeps only avocado env variables
+and variables from test's `kwargs`::
+
+  Runnable("exec-test", "examples/tests/sleeptest.sh", config={'runner.exectest.clear_env': True}, SLEEP_LENGTH=1)
diff --git a/selftests/check.py b/selftests/check.py
index 11c1800eb5..436044fc89 100755
--- a/selftests/check.py
+++ b/selftests/check.py
@@ -29,7 +29,7 @@
     "nrunner-requirement": 16,
     "unit": 668,
     "jobs": 11,
-    "functional-parallel": 302,
+    "functional-parallel": 303,
     "functional-serial": 4,
     "optional-plugins": 0,
     "optional-plugins-golang": 2,
diff --git a/selftests/functional/basic.py b/selftests/functional/basic.py
index 24a2070021..8beebb39b6 100644
--- a/selftests/functional/basic.py
+++ b/selftests/functional/basic.py
@@ -1112,6 +1112,15 @@ def test_env_var_disable(self):
                 "'returncode': 1", result, "The env variable was not disabled"
             )
 
+    @skipUnlessPathExists("/bin/sh")
+    def test_env_clear(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} -c '{{\"runner.exectest.clear_env\": true}}'"
+            )
+            result = res.stdout_text.split("\n")[-2]
+            self.assertIn("'returncode': 1", result, "The environment was not cleared.")
+
     def tearDown(self):
         self.pass_script.remove()
         self.fail_script.remove()