Add tests for scenarii around hardlinks

Author: ovalenti

tests/test_file_open.py

@@ -274,3 +274,99 @@ def test_unmonitored_mounted_dir(
     )
 
     server.wait_events([event])
+
+
+def test_open_via_hardlink(monitored_dir, server):
+    """
+    Tests opening a file through a hardlink path when the original exists.
+    The event should report the hardlink path as host_path.
+
+    Args:
+        monitored_dir: Temporary directory path for creating test files.
+        server: The server instance to communicate with.
+    """
+    process = Process.from_proc()
+
+    # Create original file
+    original = os.path.join(monitored_dir, 'original.txt')
+    with open(original, 'w') as f:
+        f.write('test content')
+
+    # Create hardlink
+    hardlink = os.path.join(monitored_dir, 'hardlink.txt')
+    os.link(original, hardlink)
+
+    # Open through hardlink
+    with open(hardlink, 'r') as f:
+        f.read()
+
+    events = [
+        Event(
+            process=process,
+            event_type=EventType.CREATION,
+            file=original,
+            host_path=original,
+        ),
+        Event(
+            process=process,
+            event_type=EventType.CREATION,
+            file=hardlink,
+            host_path=hardlink,
+        ),
+        Event(
+            process=process,
+            event_type=EventType.OPEN,
+            file=hardlink,
+            host_path=hardlink,
+        ),
+    ]
+
+    server.wait_events(events)
+
+
+def test_open_via_original_with_hardlink(monitored_dir, server):
+    """
+    Tests opening a file through its original path when a hardlink exists.
+    Both paths should be tracked for the same inode.
+
+    Args:
+        monitored_dir: Temporary directory path for creating test files.
+        server: The server instance to communicate with.
+    """
+    process = Process.from_proc()
+
+    # Create original file
+    original = os.path.join(monitored_dir, 'original.txt')
+    with open(original, 'w') as f:
+        f.write('test content')
+
+    # Create hardlink
+    hardlink = os.path.join(monitored_dir, 'hardlink.txt')
+    os.link(original, hardlink)
+
+    # Open through original path
+    with open(original, 'r') as f:
+        f.read()
+
+    events = [
+        Event(
+            process=process,
+            event_type=EventType.CREATION,
+            file=original,
+            host_path=original,
+        ),
+        Event(
+            process=process,
+            event_type=EventType.CREATION,
+            file=hardlink,
+            host_path=hardlink,
+        ),
+        Event(
+            process=process,
+            event_type=EventType.OPEN,
+            file=original,
+            host_path=original,
+        ),
+    ]
+
+    server.wait_events(events)

tests/test_path_chmod.py

@@ -336,3 +336,52 @@ def test_unmonitored_mounted_dir(
     )
 
     server.wait_events([event])
+
+
+def test_chmod_hardlink(monitored_dir, server):
+    """
+    Tests chmod on a file with hardlinks. The chmod affects the inode,
+    but the event should report the specific path being used.
+
+    Args:
+        monitored_dir: Temporary directory path for creating test files.
+        server: The server instance to communicate with.
+    """
+    process = Process.from_proc()
+    mode = 0o600
+
+    # Create original file
+    original = os.path.join(monitored_dir, 'original.txt')
+    with open(original, 'w') as f:
+        f.write('test content')
+
+    # Create hardlink
+    hardlink = os.path.join(monitored_dir, 'hardlink.txt')
+    os.link(original, hardlink)
+
+    # chmod through hardlink path
+    os.chmod(hardlink, mode)
+
+    events = [
+        Event(
+            process=process,
+            event_type=EventType.CREATION,
+            file=original,
+            host_path=original,
+        ),
+        Event(
+            process=process,
+            event_type=EventType.CREATION,
+            file=hardlink,
+            host_path=hardlink,
+        ),
+        Event(
+            process=process,
+            event_type=EventType.PERMISSION,
+            file=hardlink,
+            host_path=hardlink,
+            mode=mode,
+        ),
+    ]
+
+    server.wait_events(events)

tests/test_path_chown.py

@@ -263,3 +263,72 @@ def test_no_change(
     ]
 
     server.wait_events(events)
+
+
+def test_chown_hardlink(test_container, server):
+    """
+    Tests chown on a file with hardlinks. The chown affects the inode,
+    but the event should report the specific path being used.
+
+    Args:
+        test_container: A container for running commands in.
+        server: The server instance to communicate with.
+    """
+    # File Under Test
+    original = '/container-dir/original.txt'
+    hardlink = '/container-dir/hardlink.txt'
+
+    touch_cmd = f'touch {original}'
+    link_cmd = f'ln {original} {hardlink}'
+    chown_cmd = f'chown {TEST_UID}:{TEST_GID} {hardlink}'
+
+    # Create file and hardlink
+    test_container.exec_run(touch_cmd)
+    test_container.exec_run(link_cmd)
+
+    # chown through hardlink path
+    test_container.exec_run(chown_cmd)
+
+    touch = Process.in_container(
+        exe_path='/usr/bin/touch',
+        args=touch_cmd,
+        name='touch',
+        container_id=test_container.id[:12],
+    )
+    ln = Process.in_container(
+        exe_path='/usr/bin/ln',
+        args=link_cmd,
+        name='ln',
+        container_id=test_container.id[:12],
+    )
+    chown = Process.in_container(
+        exe_path='/usr/bin/chown',
+        args=chown_cmd,
+        name='chown',
+        container_id=test_container.id[:12],
+    )
+
+    events = [
+        Event(
+            process=touch,
+            event_type=EventType.CREATION,
+            file=original,
+            host_path='',
+        ),
+        Event(
+            process=ln,
+            event_type=EventType.CREATION,
+            file=hardlink,
+            host_path='',
+        ),
+        Event(
+            process=chown,
+            event_type=EventType.OWNERSHIP,
+            file=hardlink,
+            host_path='',
+            owner_uid=TEST_UID,
+            owner_gid=TEST_GID,
+        ),
+    ]
+
+    server.wait_events(events)