Introduce setup and teardown fixture

With this change, multiple test modules triggered from testcases/mount
can be run as individual tests complying to pytest standards.
Also any number of new tests can be added efficiently on the mount.

Old approach:
-  All the different tests are called from test_mount.py:
   https://github.com/samba-in-kubernetes/sit-test-cases/blob/main/testcases/mount/test_mount.py
-  Test_mount.py creates a mount, the required tests are called and then test_mount.py cleans the mount.

New approach :
-  This PR complies with the proposal to use fixtures in order to remove all the load on one single
   module:
   samba-in-kubernetes#25 (comment)
   samba-in-kubernetes#25 (comment)
-  The tests are no more called from test_mount.py.
-  Setting up of mount and tearing down of mount is taken care by setup and teardown fixture
   which is defined in testcases/mount/conftest.py

   More information about fixtures:
   https://docs.pytest.org/en/6.2.x/fixture.html
-  With this change, test files remain the same, but the initiator function starts with keyword test
   and the each test module starts with keyword 'test'

   That way the tests are called by pytest.
   Usage of setup and teardown fixture becomes easily possible.
   We no more need to to call the test function explictly.

   This also helps with easy debugging and better understanding of the code, as the tests will be
   failed at individual mount/IO test.

   In this case, pytest clearly points which test among test_mount_io.py, test_mount_dbm.py
   and test_mount_stress.py are failing.
   Can be very useful
   - when more and more tests are added
   - when we want to parse test results in sit-environment project

Fixes: samba-in-kubernetes#30
Signed-off-by: Shwetha K Acharya <Shwetha.K.Acharya@ibm.com>

testcases/mount/conftest.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+
+import pytest
+import os
+import shutil
+import testhelper
+import typing
+from pathlib import Path
+
+test_info_file = os.getenv("TEST_INFO_FILE")
+test_info = testhelper.read_yaml(test_info_file)
+
+
+@pytest.fixture
+def setup_mount(
+    first_ipaddr: str, share_name: str
+) -> typing.Generator[Path, None, None]:
+    flag_mounted: bool = False
+    tmp_root = testhelper.get_tmp_root()
+    mount_point = testhelper.get_tmp_mount_point(tmp_root)
+    try:
+        mount_params = testhelper.get_mount_parameters(
+            testhelper.read_yaml(test_info_file), share_name
+        )
+        mount_params["host"] = first_ipaddr
+
+        # mount cifs share
+        testhelper.cifs_mount(mount_params, mount_point)
+        flag_mounted = True
+        test_dir = mount_point / "mount_test"
+        test_dir.mkdir()
+    except Exception as e:
+        raise Exception(f"Setup failed: {str(e)}")
+
+    # Yield the setup result
+    yield test_dir
+
+    # Perform teardown after the test has run
+    try:
+        if flag_mounted and test_dir:
+            shutil.rmtree(test_dir, ignore_errors=True)
+            testhelper.cifs_umount(mount_point)
+        mount_point.rmdir()
+        tmp_root.rmdir()
+    except Exception as e:
+        raise Exception(f"Teardown failed: {str(e)}")
+
+
+def generate_mount_check() -> typing.List[typing.Tuple[str, str]]:
+    first_ipaddr = test_info["public_interfaces"][0]
+    exported_sharenames = test_info.get("exported_sharenames", [])
+    arr = []
+    for share_name in exported_sharenames:
+        arr.append((first_ipaddr, share_name))
+    return arr

testcases/mount/mount_dbm.py → testcases/mount/test_mount_dbm.py

@@ -1,13 +1,15 @@
 #!/usr/bin/env python3
 # Test various database operations via SMB mount-point.
 
+import pytest
 import dbm
 import hashlib
 import pickle
 import shutil
 import typing
 import random
 from pathlib import Path
+from .conftest import generate_mount_check
 
 
 class Record:
@@ -89,8 +91,9 @@ def _check_dbm_consistency(base: Path, nrecs: int) -> None:
         db.destroy()
 
 
-def check_dbm_consistency(rootdir: Path) -> None:
-    base = rootdir / "dbm-consistency"
+@pytest.mark.parametrize("first_ipaddr,share_name", generate_mount_check())
+def test_dbm_consistency(setup_mount: Path) -> None:
+    base = setup_mount / "dbm-consistency"
     base.mkdir(parents=True, exist_ok=True)
     try:
         _check_dbm_consistency(base, 10)

testcases/mount/mount_io.py → testcases/mount/test_mount_io.py

@@ -2,12 +2,14 @@
 
 # Test various file-system I/O operations via local SMB mount-point.
 
+import pytest
 import datetime
 import shutil
 import typing
 import testhelper
 import random
 from pathlib import Path
+from .conftest import generate_mount_check
 
 
 class DataPath:
@@ -99,11 +101,11 @@ def _run_checks(dsets: typing.List[DataPath]) -> None:
         dset.verify_noent()
 
 
-def _check_io_consistency(rootdir: Path) -> None:
+def _check_io_consistency(test_dir: Path) -> None:
     base = None
     try:
         print("\n")
-        base = rootdir / "test_io_consistency"
+        base = test_dir / "test_io_consistency"
         base.mkdir(parents=True)
         # Case-1: single 4K file
         _run_checks(_make_datasets(base, 4096, 1))
@@ -127,6 +129,7 @@ def _reset_random_seed() -> None:
     random.seed(seed)
 
 
-def check_io_consistency(rootdir: Path) -> None:
+@pytest.mark.parametrize("first_ipaddr,share_name", generate_mount_check())
+def test_check_io_consistency(setup_mount: Path) -> None:
     _reset_random_seed()
-    _check_io_consistency(rootdir)
+    _check_io_consistency(setup_mount)

testcases/mount/mount_stress.py → testcases/mount/test_mount_stress.py

@@ -1,6 +1,8 @@
+import pytest
 import threading
 import testhelper
 from pathlib import Path
+from .conftest import generate_mount_check
 
 
 def _perform_file_operations(
@@ -43,14 +45,17 @@ def _stress_test(
     print("Stress test complete.")
 
 
-def check_mnt_stress(root_dir: Path) -> None:
-    _stress_test(root_dir, num_clients=5, num_operations=20, file_size=2**22)
+@pytest.mark.parametrize("first_ipaddr,share_name", generate_mount_check())
+def test_check_mnt_stress(setup_mount: Path) -> None:
     _stress_test(
-        root_dir, num_clients=10, num_operations=30, file_size=2**23
+        setup_mount, num_clients=5, num_operations=20, file_size=2**22
     )
     _stress_test(
-        root_dir, num_clients=20, num_operations=40, file_size=2**24
+        setup_mount, num_clients=10, num_operations=30, file_size=2**23
     )
     _stress_test(
-        root_dir, num_clients=15, num_operations=25, file_size=2**25
+        setup_mount, num_clients=20, num_operations=40, file_size=2**24
+    )
+    _stress_test(
+        setup_mount, num_clients=15, num_operations=25, file_size=2**25
     )