[PATCH net-next] 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>
---
 tools/testing/selftests/drivers/net/lib/py/env.py | 14 +++++++++++++-
 tools/testing/selftests/net/lib/py/__init__.py    |  7 +++++++
 tools/testing/selftests/net/lib/py/utils.py       | 14 ++++++++++++++
 3 files changed, 34 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 a5e800b8f103..ec53cf59e104 100644
--- a/tools/testing/selftests/drivers/net/lib/py/env.py
+++ b/tools/testing/selftests/drivers/net/lib/py/env.py
@@ -4,7 +4,7 @@ import os
 import time
 from pathlib import Path
 from lib.py import KsftSkipEx, KsftXfailEx
-from lib.py import cmd, ethtool, ip
+from lib.py import cmd, ethtool, ip, verbosity_ctl
 from lib.py import NetNS, NetdevSimDev
 from .remote import Remote
 
@@ -42,6 +42,12 @@ class NetDrvEnv:
 
         self.env = _load_env_file(src_path)
 
+        try:
+            verbosity_ctl(level=int(self.env.get('VERBOSE', 0)))
+        except ValueError as e:
+            print(f'Ignoring \'VERBOSE\'. Unknown value \'{self.env.get("VERBOSE")}\'')
+            verbosity_ctl(level=0)
+
         if 'NETIF' in self.env:
             self.dev = ip("link show dev " + self.env['NETIF'], json=True)[0]
         else:
@@ -92,6 +98,12 @@ class NetDrvEpEnv:
         self._ns = None
         self._ns_peer = None
 
+        try:
+            verbosity_ctl(level=int(self.env.get('VERBOSE', 0)))
+        except ValueError as e:
+            print(f'Ignoring \'VERBOSE\'. Unknown value \'{self.env.get("VERBOSE")}\'')
+            verbosity_ctl(level=0)
+
         if "NETIF" in self.env:
             if nsim_test is True:
                 raise KsftXfailEx("Test only works on netdevsim")
diff --git a/tools/testing/selftests/net/lib/py/__init__.py b/tools/testing/selftests/net/lib/py/__init__.py
index b6d498d125fe..1541079fadce 100644
--- a/tools/testing/selftests/net/lib/py/__init__.py
+++ b/tools/testing/selftests/net/lib/py/__init__.py
@@ -1,8 +1,15 @@
 # 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
+
+try:
+    verbosity_ctl(level=int(os.environ.get('VERBOSE', 0)))
+except ValueError as e:
+    print(f'Ignoring \'VERBOSE\'. Unknown value \'{os.environ.get("VERBOSE")}\'')
+    verbosity_ctl(level=0)
diff --git a/tools/testing/selftests/net/lib/py/utils.py b/tools/testing/selftests/net/lib/py/utils.py
index 72590c3f90f1..4a59958649be 100644
--- a/tools/testing/selftests/net/lib/py/utils.py
+++ b/tools/testing/selftests/net/lib/py/utils.py
@@ -9,6 +9,18 @@ import subprocess
 import time
 
 
+def verbosity_ctl(level=None):
+    global VERBOSITY_LEVEL
+    if level is not None:
+        VERBOSITY_LEVEL = level
+    return VERBOSITY_LEVEL
+
+
+def verbose(*objs, **kwargs):
+    if verbosity_ctl() >= 1:
+        print(*objs, **kwargs)
+
+
 class CmdExitFailure(Exception):
     pass
 
@@ -22,6 +34,8 @@ class cmd:
         self.stderr = None
         self.ret = None
 
+        verbose("#cmd|", comm)
+
         self.comm = comm
         if host:
             self.proc = host.cmd(comm)
-- 
2.43.0