Introduce test-specific environment variables

This commit adds two new functions to the integration tests utilities:

get_test_env_value(varname: str, default_value: str) -> str
get_test_env_value_int(varname: str, default_value: int) -> int

This allows to set and get test-specific environment variables easily.

Use case:
Say we have an integration test, in which we want to assign a value
for a variable WAIT_TIMEOUT externally from the environment, but we
don't want to create a new fixture for it, as this value would be used
only in this specific test. The expected environment variable name
would be assembled from the prefix `TEST_`, test name (i.e. the
directory name in which the test script is located) and the provided
suffix, e.g. in test named `bluechi-generic-test`, the expected
environment variable would be `TEST_BLUECHI_GENERIC_TEST_WAIT_TIMEOUT`

Thus, using
`WAIT_TIMEOUT = get_test_env_value_int("WAIT_TIMEOUT", 1000)`
in the test named `bluechi-generic-test` will set WAIT_TIMEOUT the
value of 1000, unless `TEST_BLUECHI_GENERIC_TEST_WAIT_TIMEOUT`
environment variable is set with an integer value, which in that case
would be assigned to `WAIT_TIMEOUT`

Signed-off-by: Mark Kemel <[email protected]>

tests/README.md

@@ -184,6 +184,20 @@ TIMEOUT_COLLECT_TEST_RESULTS=20
 
 These can be set either in the `environment` section of the tmt plan or using the `-e` option when running tmt, e.g. `-eTIMEOUT_TEST_SETUP=40`.
 
+### Test-specific timeouts
+
+In addition to the mentioned above timeouts, there's a mechanism allowing to set values in specific tests via environment variables, which can be used to adjust test-specific timeouts via the environment. The expected environment variable name would be assembled from the prefix `TEST_`, test name and a provided suffix. These test-specific timeouts can be set in the tmt plan as described [here](#changing-timeouts-for-integration-tests).
+
+#### Example
+
+Given a test named `bluechi-generic-test` (i.e. the test script located in the directory `bluechi-generic-test`), which uses a timeout `WAIT_TIMEOUT`, defining it as follows:
+
+```python
+WAIT_TIMEOUT = get_test_env_value_int("WAIT_TIMEOUT", 1000)
+```
+
+The variable would be assigned `WAIT_TIMEOUT = 1000`, unless environment variable `TEST_BLUECHI_GENERIC_TEST_WAIT_TIMEOUT` is set with an integer value, in which case this value would be passed to `WAIT_TIMEOUT`.
+
 ## Developing integration tests
 
 ### Code Style

tests/bluechi_test/fixtures.py

@@ -11,97 +11,84 @@
 import yaml
 from bluechi_test.config import BluechiAgentConfig, BluechiControllerConfig
 from bluechi_test.test import BluechiContainerTest, BluechiSSHTest, BluechiTest
-from bluechi_test.util import get_primary_ip
+from bluechi_test.util import get_env_value, get_primary_ip, safely_parse_int
 from podman import PodmanClient
 
 
-def _get_env_value(env_var: str, default_value: str) -> str:
-    value = os.getenv(env_var)
-    if value is None:
-        return default_value
-    return value
-
-
 @pytest.fixture(scope="session")
 def tmt_test_data_dir() -> str:
     """Return directory, where tmt saves data of the relevant test. If the TMT_TEST_DATA env variable is not set, then
     use current directory"""
-    return _get_env_value("TMT_TEST_DATA", os.getcwd())
+    return get_env_value("TMT_TEST_DATA", os.getcwd())
 
 
 @pytest.fixture(scope="function")
 def tmt_test_serial_number() -> str:
     """Return serial number of current test"""
-    return _get_env_value("TMT_TEST_SERIAL_NUMBER", "NA")
+    return get_env_value("TMT_TEST_SERIAL_NUMBER", "NA")
 
 
 @pytest.fixture(scope="session")
 def bluechi_image_name() -> str:
     """Returns the name of bluechi testing container images"""
-    return _get_env_value("BLUECHI_IMAGE_NAME", "bluechi-image")
+    return get_env_value("BLUECHI_IMAGE_NAME", "bluechi-image")
 
 
 @pytest.fixture(scope="session")
 def bluechi_ctrl_host_port() -> str:
     """Returns the port, which bluechi controller service is mapped to on a host"""
 
-    return _get_env_value("BLUECHI_CTRL_HOST_PORT", "8420")
+    return get_env_value("BLUECHI_CTRL_HOST_PORT", "8420")
 
 
 @pytest.fixture(scope="session")
 def bluechi_ctrl_svc_port() -> str:
     """Returns the port, which bluechi controller service is using inside a container"""
 
-    return _get_env_value("BLUECHI_CTRL_SVC_PORT", "8420")
+    return get_env_value("BLUECHI_CTRL_SVC_PORT", "8420")
 
 
 @pytest.fixture(scope="session")
 def machines_ssh_user() -> str:
     """Returns the user for connecting to the available hosts via SSH"""
 
-    return _get_env_value("SSH_USER", "root")
+    return get_env_value("SSH_USER", "root")
 
 
 @pytest.fixture(scope="session")
 def machines_ssh_password() -> str:
     """Returns the password for connecting to the available hosts via SSH"""
 
-    return _get_env_value("SSH_PASSWORD", "")
-
-
-def _safely_parse_int(input: str, default: int) -> int:
-    if input.isdigit():
-        return int(input)
-    return default
+    return get_env_value("SSH_PASSWORD", "")
 
 
 @pytest.fixture(scope="session")
 def timeout_test_setup() -> int:
     """Returns the timeout for setting up the test setup"""
 
-    return _safely_parse_int(_get_env_value("TIMEOUT_TEST_SETUP", ""), 20)
+    return safely_parse_int(get_env_value("TIMEOUT_TEST_SETUP", ""), 20)
 
 
 @pytest.fixture(scope="session")
 def timeout_test_run() -> int:
     """Returns the timeout for executing the actual test"""
 
-    return _safely_parse_int(_get_env_value("TIMEOUT_TEST_RUN", ""), 45)
+    return safely_parse_int(get_env_value("TIMEOUT_TEST_RUN", ""), 45)
 
 
 @pytest.fixture(scope="session")
 def timeout_collecting_test_results() -> int:
     """Returns the timeout for collecting all test results"""
 
-    return _safely_parse_int(_get_env_value("TIMEOUT_COLLECT_TEST_RESULTS", ""), 20)
+    return safely_parse_int(get_env_value("TIMEOUT_COLLECT_TEST_RESULTS", ""), 20)
 
 
 def _read_topology() -> Dict[str, Any]:
     """
     Returns the parsed YAML for the tmt guest topology:
     https://tmt.readthedocs.io/en/stable/spec/plans.html#guest-topology-format
     """
-    tmt_yaml_file = _get_env_value("TMT_TOPOLOGY_YAML", "")
+    tmt_yaml_file = get_env_value("TMT_TOPOLOGY_YAML", "")
     if tmt_yaml_file is None or tmt_yaml_file == "":
         return get_primary_ip()
 
@@ -170,14 +157,14 @@ def is_multihost_run(available_hosts: Dict[str, List[Tuple[str, str]]]) -> bool:
 def run_with_valgrind() -> bool:
     """Returns 1 if bluechi should be run with valgrind for memory management testing"""
 
-    return _get_env_value("WITH_VALGRIND", 0) == "1"
+    return get_env_value("WITH_VALGRIND", 0) == "1"
 
 
 @pytest.fixture(scope="session")
 def run_with_coverage() -> bool:
     """Returns 1 if code coverage should be collected"""
 
-    return _get_env_value("WITH_COVERAGE", 0) == "1"
+    return get_env_value("WITH_COVERAGE", 0) == "1"
 
 
 @pytest.fixture(scope="session")

tests/bluechi_test/util.py

@@ -3,7 +3,9 @@
 #
 # SPDX-License-Identifier: LGPL-2.1-or-later
 
+import inspect
 import logging
+import os
 import random
 import re
 import signal
@@ -84,3 +86,33 @@ def __enter__(self):
 
     def __exit__(self, type, value, traceback):
         signal.alarm(0)
+
+
+def get_env_value(env_var: str, default_value: str) -> str:
+    value = os.getenv(env_var)
+    if value is None:
+        return default_value
+    return value
+
+
+def safely_parse_int(input: str, default: int) -> int:
+    if input.isdigit():
+        return int(input)
+    return default
+
+
+def _get_test_env_value(varname: str, test_file: str, default_value: str) -> str:
+    test_name = os.path.basename(os.path.dirname(test_file))
+    envvar = f"TEST_{test_name.upper().replace('-', '_')}_{varname.upper()}"
+    return get_env_value(envvar, default_value)
+
+
+def get_test_env_value(varname: str, default_value: str) -> str:
+    test_file = inspect.stack()[1].filename
+    return _get_test_env_value(varname, test_file, default_value)
+
+
+def get_test_env_value_int(varname: str, default_value: int) -> int:
+    test_file = inspect.stack()[1].filename
+    value = _get_test_env_value(varname, test_file, "")
+    return safely_parse_int(value, default_value)