vyos.util: extend process_named_running() signature with cmdline

process_named_running() was introduced in commit 16b2fc8fc4ca ("dns-forwarding:
T2298: fix path to control file") and thus remained more or less unchanged.

Smoketests use process_named_running() heavily and might spawn multiple
processes with the same name but ifferent options (e.g. dhcp6c or dhclient) and
it was yet not possible to properly filter on the "real-deal" like the process
bound to a given interface.

One can now optionally specify a string that is searched inside the command
line argument list of the process.

Example:

>>> process_named_running('dhcp6c', 'veth0')
['/usr/sbin/dhcp6c', '-D', '-k', '/run/dhcp6c/dhcp6c.veth0.sock', '-c',
 '/run/dhcp6c/dhcp6c.veth0.conf', '-p', '/run/dhcp6c/dhcp6c.veth0.pid', 'veth0']
4215

>>> process_named_running('dhcp6c', 'veth1')
['/usr/sbin/dhcp6c', '-D', '-k', '/run/dhcp6c/dhcp6c.veth1.sock', '-c',
 '/run/dhcp6c/dhcp6c.veth1.conf', '-p', '/run/dhcp6c/dhcp6c.veth1.pid', 'veth1']
4253

Where the debug list returned is the commandline searched.

1 files changed, 7 insertions, 4 deletions

diff --git a/python/vyos/util.py b/python/vyos/util.py
index d5330db13..61ce59324 100644
--- a/python/vyos/util.py
+++ b/python/vyos/util.py
@@ -463,14 +463,17 @@ def process_running(pid_file):
         pid = f.read().strip()
     return pid_exists(int(pid))
 
-def process_named_running(name):
+def process_named_running(name, cmdline: str=None):
     """ Checks if process with given name is running and returns its PID.
     If Process is not running, return None
     """
     from psutil import process_iter
-    for p in process_iter():
-        if name in p.name():
-            return p.pid
+    for p in process_iter(['name', 'pid', 'cmdline']):
+        if cmdline:
+            if p.info['name'] == name and cmdline in p.info['cmdline']:
+                return p.info['pid']
+        elif p.info['name'] == name:
+            return p.info['pid']
     return None
 
 def is_list_equal(first: list, second: list) -> bool: