vyos.util: increase usage of process_running() and remove duplicated code

OpenVPN, WIFI, SSTP all had the same boiler plate copied about checking if a
process associated with a pidfile is running or not. This has been migrated to
the common library function vyos.util.process_running().

5 files changed, 21 insertions, 46 deletions

diff --git a/python/vyos/util.py b/python/vyos/util.py
index 635b11ee5..67aa87a3a 100644
--- a/python/vyos/util.py
+++ b/python/vyos/util.py
@@ -84,6 +84,8 @@ def colon_separated_to_dict(data_string, uniquekeys=False):
 
 def process_running(pid_file):
     """ Checks if a process with PID in pid_file is running """
+    if not os.path.isfile(pid_file):
+        return False
     with open(pid_file, 'r') as f:
         pid = f.read().strip()
     return psutil.pid_exists(int(pid))
diff --git a/src/conf_mode/interfaces-openvpn.py b/src/conf_mode/interfaces-openvpn.py
index 17aa4697f..fb2d6e6d9 100755
--- a/src/conf_mode/interfaces-openvpn.py
+++ b/src/conf_mode/interfaces-openvpn.py
@@ -24,7 +24,6 @@ from stat import S_IRUSR,S_IRWXU,S_IRGRP,S_IXGRP,S_IROTH,S_IXOTH
 from grp import getgrnam
 from ipaddress import ip_address,ip_network,IPv4Interface
 from netifaces import interfaces
-from psutil import pid_exists
 from pwd import getpwnam
 from subprocess import Popen, PIPE
 from time import sleep
@@ -33,6 +32,7 @@ from shutil import rmtree
 from vyos import ConfigError
 from vyos.config import Config
 from vyos.ifconfig import VTunIf
+from vyos.util import process_running
 from vyos.validate import is_addr_assigned
 
 user = 'openvpn'
@@ -977,17 +977,12 @@ def generate(openvpn):
     return None
 
 def apply(openvpn):
-    pid = 0
     pidfile = '/var/run/openvpn/{}.pid'.format(openvpn['intf'])
-    if os.path.isfile(pidfile):
-        pid = 0
-        with open(pidfile, 'r') as f:
-            pid = int(f.read())
 
     # Always stop OpenVPN service. We can not send a SIGUSR1 for restart of the
     # service as the configuration is not re-read. Stop daemon only if it's
     # running - it could have died or killed by someone evil
-    if pid_exists(pid):
+    if process_running(pidfile):
         cmd = 'start-stop-daemon'
         cmd += ' --stop '
         cmd += ' --quiet'
diff --git a/src/conf_mode/interfaces-wireless.py b/src/conf_mode/interfaces-wireless.py
index 454ad96dc..82a80d247 100755
--- a/src/conf_mode/interfaces-wireless.py
+++ b/src/conf_mode/interfaces-wireless.py
@@ -25,15 +25,15 @@ from grp import getgrnam
 from re import findall
 
 from subprocess import Popen, PIPE
-from psutil import pid_exists
 from netifaces import interfaces
 from netaddr import *
 
-from vyos.ifconfig import WiFiIf
-from vyos.ifconfig_vlan import apply_vlan_config, verify_vlan_config
+from vyos import ConfigError
 from vyos.configdict import list_diff, vlan_to_dict
 from vyos.config import Config
-from vyos import ConfigError
+from vyos.ifconfig import WiFiIf
+from vyos.ifconfig_vlan import apply_vlan_config, verify_vlan_config
+from vyos.util import process_running
 
 user = 'root'
 group = 'vyattacfg'
@@ -1364,15 +1364,9 @@ def verify(wifi):
     return None
 
 def generate(wifi):
-    pid = 0
     # always stop hostapd service first before reconfiguring it
     pidfile = get_pid('hostapd', wifi['intf'])
-    if os.path.isfile(pidfile):
-        pid = 0
-        with open(pidfile, 'r') as f:
-            pid = int(f.read())
-
-    if pid_exists(pid):
+    if process_running(pidfile):
         cmd = 'start-stop-daemon'
         cmd += ' --stop '
         cmd += ' --quiet'
@@ -1382,12 +1376,7 @@ def generate(wifi):
 
     # always stop wpa_supplicant service first before reconfiguring it
     pidfile = get_pid('wpa_supplicant', wifi['intf'])
-    if os.path.isfile(pidfile):
-        pid = 0
-        with open(pidfile, 'r') as f:
-            pid = int(f.read())
-
-    if pid_exists(pid):
+    if process_running(pidfile):
         cmd = 'start-stop-daemon'
         cmd += ' --stop '
         cmd += ' --quiet'
diff --git a/src/conf_mode/vpn_sstp.py b/src/conf_mode/vpn_sstp.py
index 8e5c7587c..070437443 100755
--- a/src/conf_mode/vpn_sstp.py
+++ b/src/conf_mode/vpn_sstp.py
@@ -23,9 +23,9 @@ from subprocess import Popen, PIPE, check_output
 from socket import socket, AF_INET, SOCK_STREAM
 from copy import deepcopy
 from stat import S_IRUSR, S_IWUSR, S_IRGRP
-from psutil import pid_exists
 
 from vyos.config import Config
+from vyos.util import process_running
 from vyos import ConfigError
 
 pidfile = r'/var/run/accel_sstp.pid'
@@ -489,14 +489,8 @@ def generate(sstp):
     return sstp
 
 def apply(sstp):
-    pid = 0
-    if os.path.isfile(pidfile):
-        pid = 0
-        with open(pidfile, 'r') as f:
-            pid = int(f.read())
-
     if sstp is None:
-        if pid_exists(pid):
+        if process_running(pidfile):
             cmd = 'start-stop-daemon'
             cmd += ' --stop '
             cmd += ' --quiet'
@@ -509,7 +503,7 @@ def apply(sstp):
 
         return None
 
-    if not pid_exists(pid):
+    if not process_running(pidfile):
         if os.path.exists(pidfile):
             os.remove(pidfile)
 
diff --git a/src/op_mode/reset_openvpn.py b/src/op_mode/reset_openvpn.py
index 176cd51cf..4c29fbbba 100755
--- a/src/op_mode/reset_openvpn.py
+++ b/src/op_mode/reset_openvpn.py
@@ -17,10 +17,10 @@
 import sys
 import os
 
-from psutil import pid_exists
 from subprocess import Popen, PIPE
 from time import sleep
 from netifaces import interfaces
+from vyos.util import process_running
 
 def get_config_name(intf):
     cfg_file = r'/opt/vyatta/etc/openvpn/openvpn-{}.conf'.format(intf)
@@ -42,18 +42,13 @@ if __name__ == '__main__':
     interface = sys.argv[1]
     if os.path.isfile(get_config_name(interface)):
         pidfile = '/var/run/openvpn/{}.pid'.format(interface)
-        if os.path.isfile(pidfile):
-            pid = 0
-            with open(pidfile, 'r') as f:
-                pid = int(f.read())
-
-            if pid_exists(pid):
-                cmd = 'start-stop-daemon'
-                cmd += ' --stop'
-                cmd += ' --oknodo'
-                cmd += ' --quiet'
-                cmd += ' --pidfile ' + pidfile
-                subprocess_cmd(cmd)
+        if process_running(pidfile):
+            cmd = 'start-stop-daemon'
+            cmd += ' --stop'
+            cmd += ' --oknodo'
+            cmd += ' --quiet'
+            cmd += ' --pidfile ' + pidfile
+            subprocess_cmd(cmd)
 
         # When stopping OpenVPN we need to wait for the 'old' interface to
         # vanish from the Kernel, if it is not gone, OpenVPN will report: