Automated nbdkit count filter reports number of bytes read, write, zeroed, trimmed in debug log

Signed-off-by: Ganesh Hubale <ghubale@redhat.com>

Author: ganeshhubale

v2v/tests/cfg/nbdkit/nbdkit.cfg

@@ -81,6 +81,9 @@
             option_tar_limit = '0 100K 100G'
             option_tar_entry = '0 latest-rhel9.img fake-entry'
             checkpoint = 'test_tar_filter'
+          - count:
+            version_required = "[nbdkit-1.46,)"
+            checkpoint = 'test_count_filter'
       - plugin:
         variants:
           - file:

v2v/tests/src/nbdkit/nbdkit.py

@@ -809,6 +809,60 @@ def test_nbdkit_instance_name():
                         # Force kill if it's being stubborn
                         p.kill()
 
+    def test_count_filter():
+        from subprocess import Popen, TimeoutExpired
+
+        log_path = os.path.join(data_dir.get_tmp_dir(), "nbdkit_count_filter_debug.log")
+
+        try:
+            with open(log_path, "w") as log_file:
+                LOG.info("Starting nbdkit")
+                cmd = ["nbdkit", "-f", "-v", "memory", "10M", "--filter=count"]
+                # Start nbdkit as a background process, piping stderr and stdout to log file
+                p = Popen(cmd, stderr=log_file, stdout=log_file)
+
+            if p.poll() is not None:
+                test.fail(f"nbdkit failed to start! Check {log_path}")
+
+            # Allow nbdkit instances time to start listening
+            import time
+            time.sleep(1)
+
+            # Trigger activity with qemu-io
+            LOG.info("Writing data to nbdkit")
+            qemu_cmd = "qemu-io -f raw nbd://localhost -c \'write 0 1M\' -c \'read 0 1M\' -c \'write -z 1M 1M\' -c \'discard 0 1M\'"
+
+            result = process.run(qemu_cmd, shell=True)
+            if result.exit_status != 0:
+                test.fail("qemu-io failed")
+
+            # VALIDATION: Check the log file for the read, written, zeroed, trimmed  reports
+            with open(log_path, 'r') as f:
+                log_content = f.read()
+                # Look for the expected pattern
+                expected_patterns = [
+                    "count: pwrite count=1048576",
+                    "count: pread count=1048576",
+                    "count: pzero count=1048576",
+                    "count: trim count=1048576"
+                ]
+
+                for pattern in expected_patterns:
+                    if pattern not in log_content:
+                        test.fail(f"'{pattern}' was not found in debug logs!")
+                    LOG.info(f"Pattern {pattern} appears in the debug logs")
+        finally:
+            # Cleanup: Kill the processes
+            LOG.info("Cleanup: Kill the processes")
+            if p.poll() is None:
+                p.terminate()
+                try:
+                    # Wait up to 5 seconds for it to exit
+                    p.wait(timeout=5)
+                except TimeoutExpired:
+                    # Force kill if it's being stubborn
+                    p.kill()
+
     if version_required and not multiple_versions_compare(
             version_required):
         test.cancel("Testing requires version: %s" % version_required)
@@ -889,5 +943,7 @@ def test_nbdkit_instance_name():
         check_blocksize_constraints()
     elif checkpoint == 'test_nbdkit_instance_name':
         test_nbdkit_instance_name()
+    elif checkpoint == 'test_count_filter':
+        test_count_filter()
     else:
         test.error('Not found testcase: %s' % checkpoint)