[PATCH net-next v2] selftests: net: py: support verbose printing, display executed commands

[Mohsin Bashir <mohsin.bashr@gmail.com>]

Add verbosity support to show the commands executed while
running tests. Enable verbosity if either an environment
variable 'VERBOSE' is set to a non-zero number or it is defined
in a config file under driver tests as discussed here:
https://github.com/linux-netdev/nipa/wiki/Running-driver-tests.

Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
Changes in v2:
- change verbosity_ctl to set_verbosity
- remove redundency in the code

v1: https://lore.kernel.org/netdev/20240715030723.1768360-1-mohsin.bashr@gmail.com

 .../selftests/drivers/net/lib/py/env.py       |  6 ++++-
 .../testing/selftests/net/lib/py/__init__.py  |  4 +++
 tools/testing/selftests/net/lib/py/utils.py   | 26 +++++++++++++++++++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/drivers/net/lib/py/env.py b/tools/testing/selftests/drivers/net/lib/py/env.py
index 1ea9bb695e94..c7cf52d9b988 100644
--- a/tools/testing/selftests/drivers/net/lib/py/env.py
+++ b/tools/testing/selftests/drivers/net/lib/py/env.py
@@ -5,7 +5,7 @@ import time
 from pathlib import Path
 from lib.py import KsftSkipEx, KsftXfailEx
 from lib.py import ksft_setup
-from lib.py import cmd, ethtool, ip
+from lib.py import cmd, ethtool, ip, set_verbosity
 from lib.py import NetNS, NetdevSimDev
 from .remote import Remote
 
@@ -31,6 +31,10 @@ def _load_env_file(src_path):
             if len(pair) != 2:
                 raise Exception("Can't parse configuration line:", full_file)
             env[pair[0]] = pair[1]
+
+    env_level = env.get('VERBOSE')
+    set_verbosity(env_level)
+
     return ksft_setup(env)
 
 
diff --git a/tools/testing/selftests/net/lib/py/__init__.py b/tools/testing/selftests/net/lib/py/__init__.py
index b6d498d125fe..eb4860dea26a 100644
--- a/tools/testing/selftests/net/lib/py/__init__.py
+++ b/tools/testing/selftests/net/lib/py/__init__.py
@@ -1,8 +1,12 @@
 # SPDX-License-Identifier: GPL-2.0
 
+import os
 from .consts import KSRC
 from .ksft import *
 from .netns import NetNS
 from .nsim import *
 from .utils import *
 from .ynl import NlError, YnlFamily, EthtoolFamily, NetdevFamily, RtnlFamily
+
+env_level = os.environ.get('VERBOSE')
+set_verbosity(env_level)
diff --git a/tools/testing/selftests/net/lib/py/utils.py b/tools/testing/selftests/net/lib/py/utils.py
index 72590c3f90f1..d475f131a598 100644
--- a/tools/testing/selftests/net/lib/py/utils.py
+++ b/tools/testing/selftests/net/lib/py/utils.py
@@ -8,11 +8,35 @@ import socket
 import subprocess
 import time
 
+VERBOSITY_LEVEL = 0
+
 
 class CmdExitFailure(Exception):
     pass
 
 
+def set_verbosity(level=None):
+    global VERBOSITY_LEVEL
+
+    if level is not None:
+        try:
+            level = int(level)
+        except ValueError as e:
+            print(f'Ignoring \'VERBOSE\'. Unknown value \'{level}\'')
+            level = 0
+
+        VERBOSITY_LEVEL = level
+
+    return VERBOSITY_LEVEL
+
+
+def verbose(*objs, **kwargs):
+    global VERBOSITY_LEVEL
+
+    if VERBOSITY_LEVEL >= 1:
+        print(*objs, **kwargs)
+
+
 class cmd:
     def __init__(self, comm, shell=True, fail=True, ns=None, background=False, host=None, timeout=5):
         if ns:
@@ -22,6 +46,8 @@ class cmd:
         self.stderr = None
         self.ret = None
 
+        verbose("#cmd|", comm)
+
         self.comm = comm
         if host:
             self.proc = host.cmd(comm)
-- 
2.43.5