Merge pull request #307 from thomas-mangin/T2226

util: T2226: convert all call to use vyos.util.{popen, cmd, run}

50 files changed, 350 insertions, 363 deletions

diff --git a/src/conf_mode/accel_l2tp.py b/src/conf_mode/accel_l2tp.py
index 77e1ee874..4ca5a858a 100755
--- a/src/conf_mode/accel_l2tp.py
+++ b/src/conf_mode/accel_l2tp.py
@@ -17,7 +17,7 @@
 import sys
 import os
 import re
-import subprocess
+import jinja2
 import socket
 import time
 
@@ -26,6 +26,8 @@ from jinja2 import FileSystemLoader, Environment
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 pidfile = r'/var/run/accel_l2tp.pid'
 l2tp_cnf_dir = r'/etc/accel-ppp/l2tp'
@@ -61,17 +63,10 @@ def chk_con():
                 break
 
 
-def accel_cmd(cmd=''):
-    if not cmd:
-        return None
-    try:
-        ret = subprocess.check_output(
-            ['/usr/bin/accel-cmd', '-p', '2004', cmd]).decode().strip()
-        return ret
-    except:
-        return 1
+def _accel_cmd(command):
+  return run(f'/usr/bin/accel-cmd -p 2004 {command}')
 
-###
+### 
 # inline helper functions end
 ###
 
@@ -375,21 +370,20 @@ def generate(c):
 def apply(c):
     if c == None:
         if os.path.exists(pidfile):
-            accel_cmd('shutdown hard')
+            _accel_cmd('shutdown hard')
             if os.path.exists(pidfile):
                 os.remove(pidfile)
         return None
 
     if not os.path.exists(pidfile):
-        ret = subprocess.call(
-            ['/usr/sbin/accel-pppd', '-c', l2tp_conf, '-p', pidfile, '-d'])
+        ret = run(f'/usr/sbin/accel-pppd -c {l2tp_conf} -p {pidfile} -d')
         chk_con()
         if ret != 0 and os.path.exists(pidfile):
             os.remove(pidfile)
             raise ConfigError('accel-pppd failed to start')
     else:
         # if gw ip changes, only restart doesn't work
-        accel_cmd('restart')
+        _accel_cmd('restart')
 
 
 if __name__ == '__main__':
diff --git a/src/conf_mode/arp.py b/src/conf_mode/arp.py
index aeca08432..3daa892d7 100755
--- a/src/conf_mode/arp.py
+++ b/src/conf_mode/arp.py
@@ -20,9 +20,9 @@ import sys
 import os
 import re
 import syslog as sl
-import subprocess
 
 from vyos.config import Config
+from vyos.util import run
 from vyos import ConfigError
 
 arp_cmd = '/usr/sbin/arp'
@@ -82,11 +82,12 @@ def generate(c):
 def apply(c):
   for ip_addr in c['remove']:
     sl.syslog(sl.LOG_NOTICE, "arp -d " + ip_addr)
-    subprocess.call([arp_cmd + ' -d ' + ip_addr + ' >/dev/null 2>&1'], shell=True)
+    run(f'{arp_cmd} -d {ip_addr} >/dev/null 2>&1')
 
   for ip_addr in c['update']:
     sl.syslog(sl.LOG_NOTICE, "arp -s " + ip_addr + " " + c['update'][ip_addr])
-    subprocess.call([arp_cmd + ' -s ' + ip_addr + ' ' + c['update'][ip_addr] ], shell=True)
+    updated = c['update'][ip_addr]
+    run(f'{arp_cmd} -s {ip_addr} {updated}')
 
 
 if __name__ == '__main__':
diff --git a/src/conf_mode/bcast_relay.py b/src/conf_mode/bcast_relay.py
index 96576ddd4..f6d90776c 100755
--- a/src/conf_mode/bcast_relay.py
+++ b/src/conf_mode/bcast_relay.py
@@ -24,6 +24,7 @@ from jinja2 import FileSystemLoader, Environment
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
 
 config_file = r'/etc/default/udp-broadcast-relay'
 
@@ -154,7 +155,7 @@ def generate(relay):
 
 def apply(relay):
     # first stop all running services
-    os.system('sudo systemctl stop udp-broadcast-relay@{1..99}')
+    run('sudo systemctl stop udp-broadcast-relay@{1..99}')
 
     if (relay is None) or relay['disabled']:
         return None
@@ -164,7 +165,7 @@ def apply(relay):
         # Don't start individual instance when it's disabled
         if r['disabled']:
             continue
-        os.system('sudo systemctl start udp-broadcast-relay@{0}'.format(r['id']))
+        run('sudo systemctl start udp-broadcast-relay@{0}'.format(r['id']))
 
     return None
 
diff --git a/src/conf_mode/dhcp_relay.py b/src/conf_mode/dhcp_relay.py
index 6f8d66e7b..1d6d4c6e3 100755
--- a/src/conf_mode/dhcp_relay.py
+++ b/src/conf_mode/dhcp_relay.py
@@ -22,6 +22,7 @@ from sys import exit
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
 
 config_file = r'/etc/default/isc-dhcp-relay'
 
@@ -112,10 +113,10 @@ def generate(relay):
 
 def apply(relay):
     if relay is not None:
-        os.system('sudo systemctl restart isc-dhcp-relay.service')
+        run('sudo systemctl restart isc-dhcp-relay.service')
     else:
         # DHCP relay support is removed in the commit
-        os.system('sudo systemctl stop isc-dhcp-relay.service')
+        run('sudo systemctl stop isc-dhcp-relay.service')
         os.unlink(config_file)
 
     return None
diff --git a/src/conf_mode/dhcp_server.py b/src/conf_mode/dhcp_server.py
index 3d75414f5..69aebe2f4 100755
--- a/src/conf_mode/dhcp_server.py
+++ b/src/conf_mode/dhcp_server.py
@@ -26,6 +26,8 @@ from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos.validate import is_subnet_connected
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/dhcp/dhcpd.conf'
 lease_file = r'/config/dhcpd.leases'
@@ -626,7 +628,7 @@ def generate(dhcp):
 def apply(dhcp):
     if (dhcp is None) or dhcp['disabled']:
         # DHCP server is removed in the commit
-        os.system('sudo systemctl stop isc-dhcpv4-server.service')
+        run('sudo systemctl stop isc-dhcpv4-server.service')
         if os.path.exists(config_file):
             os.unlink(config_file)
         if os.path.exists(daemon_config_file):
@@ -636,7 +638,7 @@ def apply(dhcp):
         if not os.path.exists(lease_file):
             os.mknod(lease_file)
 
-        os.system('sudo systemctl restart isc-dhcpv4-server.service')
+        run('sudo systemctl restart isc-dhcpv4-server.service')
 
     return None
 
diff --git a/src/conf_mode/dhcpv6_relay.py b/src/conf_mode/dhcpv6_relay.py
index d942daf37..a67deb6c7 100755
--- a/src/conf_mode/dhcpv6_relay.py
+++ b/src/conf_mode/dhcpv6_relay.py
@@ -23,6 +23,8 @@ from jinja2 import FileSystemLoader, Environment
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/default/isc-dhcpv6-relay'
 
@@ -98,10 +100,10 @@ def generate(relay):
 
 def apply(relay):
     if relay is not None:
-        os.system('sudo systemctl restart isc-dhcpv6-relay.service')
+        run('sudo systemctl restart isc-dhcpv6-relay.service')
     else:
         # DHCPv6 relay support is removed in the commit
-        os.system('sudo systemctl stop isc-dhcpv6-relay.service')
+        run('sudo systemctl stop isc-dhcpv6-relay.service')
         os.unlink(config_file)
 
     return None
diff --git a/src/conf_mode/dhcpv6_server.py b/src/conf_mode/dhcpv6_server.py
index 10b40baa4..003e80915 100755
--- a/src/conf_mode/dhcpv6_server.py
+++ b/src/conf_mode/dhcpv6_server.py
@@ -25,6 +25,8 @@ from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos.validate import is_subnet_connected
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/dhcp/dhcpdv6.conf'
 lease_file = r'/config/dhcpdv6.leases'
@@ -362,7 +364,7 @@ def generate(dhcpv6):
 def apply(dhcpv6):
     if (dhcpv6 is None) or dhcpv6['disabled']:
         # DHCP server is removed in the commit
-        os.system('sudo systemctl stop isc-dhcpv6-server.service')
+        run('sudo systemctl stop isc-dhcpv6-server.service')
         if os.path.exists(config_file):
             os.unlink(config_file)
         if os.path.exists(daemon_config_file):
@@ -372,7 +374,7 @@ def apply(dhcpv6):
         if not os.path.exists(lease_file):
             os.mknod(lease_file)
 
-        os.system('sudo systemctl restart isc-dhcpv6-server.service')
+        run('sudo systemctl restart isc-dhcpv6-server.service')
 
     return None
 
diff --git a/src/conf_mode/dns_forwarding.py b/src/conf_mode/dns_forwarding.py
index bbb69cdf7..5dc599425 100755
--- a/src/conf_mode/dns_forwarding.py
+++ b/src/conf_mode/dns_forwarding.py
@@ -26,6 +26,7 @@ from vyos.defaults import directories as vyos_data_dir
 from vyos.hostsd_client import Client as hostsd_client
 from vyos.util import wait_for_commit_lock
 from vyos import ConfigError
+from vyos.util import run
 
 parser = argparse.ArgumentParser()
 parser.add_argument("--dhclient", action="store_true",
@@ -166,11 +167,11 @@ def generate(dns):
 def apply(dns):
     if dns is None:
         # DNS forwarding is removed in the commit
-        os.system("systemctl stop pdns-recursor")
+        run("systemctl stop pdns-recursor")
         if os.path.isfile(config_file):
             os.unlink(config_file)
     else:
-        os.system("systemctl restart pdns-recursor")
+        run("systemctl restart pdns-recursor")
 
 if __name__ == '__main__':
     args = parser.parse_args()
diff --git a/src/conf_mode/dynamic_dns.py b/src/conf_mode/dynamic_dns.py
index 56ce4fedc..b9163f7b3 100755
--- a/src/conf_mode/dynamic_dns.py
+++ b/src/conf_mode/dynamic_dns.py
@@ -24,6 +24,8 @@ from stat import S_IRUSR, S_IWUSR
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/ddclient/ddclient.conf'
 cache_file = r'/var/cache/ddclient/ddclient.cache'
@@ -255,11 +257,11 @@ def apply(dyndns):
         os.unlink('/etc/ddclient.conf')
 
     if dyndns['deleted']:
-        os.system('/etc/init.d/ddclient stop')
+        run('/etc/init.d/ddclient stop')
         if os.path.exists(dyndns['pid_file']):
             os.unlink(dyndns['pid_file'])
     else:
-        os.system('/etc/init.d/ddclient restart')
+        run('/etc/init.d/ddclient restart')
 
     return None
 
diff --git a/src/conf_mode/firewall_options.py b/src/conf_mode/firewall_options.py
index 2be80cdbf..90f004bc4 100755
--- a/src/conf_mode/firewall_options.py
+++ b/src/conf_mode/firewall_options.py
@@ -21,6 +21,8 @@ import copy
 
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import run
+
 
 default_config_data = {
     'intf_opts': [],
@@ -85,19 +87,19 @@ def apply(tcp):
     target = 'VYOS_FW_OPTIONS'
 
     # always cleanup iptables
-    os.system('iptables --table mangle --delete FORWARD --jump {} >&/dev/null'.format(target))
-    os.system('iptables --table mangle --flush {} >&/dev/null'.format(target))
-    os.system('iptables --table mangle --delete-chain {} >&/dev/null'.format(target))
+    run('iptables --table mangle --delete FORWARD --jump {} >&/dev/null'.format(target))
+    run('iptables --table mangle --flush {} >&/dev/null'.format(target))
+    run('iptables --table mangle --delete-chain {} >&/dev/null'.format(target))
 
     # always cleanup ip6tables
-    os.system('ip6tables --table mangle --delete FORWARD --jump {} >&/dev/null'.format(target))
-    os.system('ip6tables --table mangle --flush {} >&/dev/null'.format(target))
-    os.system('ip6tables --table mangle --delete-chain {} >&/dev/null'.format(target))
+    run('ip6tables --table mangle --delete FORWARD --jump {} >&/dev/null'.format(target))
+    run('ip6tables --table mangle --flush {} >&/dev/null'.format(target))
+    run('ip6tables --table mangle --delete-chain {} >&/dev/null'.format(target))
 
     # Setup new iptables rules
     if tcp['new_chain4']:
-        os.system('iptables --table mangle --new-chain {} >&/dev/null'.format(target))
-        os.system('iptables --table mangle --append FORWARD --jump {} >&/dev/null'.format(target))
+        run('iptables --table mangle --new-chain {} >&/dev/null'.format(target))
+        run('iptables --table mangle --append FORWARD --jump {} >&/dev/null'.format(target))
 
         for opts in tcp['intf_opts']:
             intf = opts['intf']
@@ -109,13 +111,13 @@ def apply(tcp):
 
             # adjust TCP MSS per interface
             if mss:
-                os.system('iptables --table mangle --append {} --out-interface {} --protocol tcp ' \
+                run('iptables --table mangle --append {} --out-interface {} --protocol tcp ' \
                           '--tcp-flags SYN,RST SYN --jump TCPMSS --set-mss {} >&/dev/null'.format(target, intf, mss))
 
     # Setup new ip6tables rules
     if tcp['new_chain6']:
-        os.system('ip6tables --table mangle --new-chain {} >&/dev/null'.format(target))
-        os.system('ip6tables --table mangle --append FORWARD --jump {} >&/dev/null'.format(target))
+        run('ip6tables --table mangle --new-chain {} >&/dev/null'.format(target))
+        run('ip6tables --table mangle --append FORWARD --jump {} >&/dev/null'.format(target))
 
         for opts in tcp['intf_opts']:
             intf = opts['intf']
@@ -127,8 +129,8 @@ def apply(tcp):
 
             # adjust TCP MSS per interface
             if mss:
-                os.system('ip6tables --table mangle --append {} --out-interface {} --protocol tcp ' \
-                          '--tcp-flags SYN,RST SYN --jump TCPMSS --set-mss {} >&/dev/null'.format(target, intf, mss))
+                run('ip6tables --table mangle --append {} --out-interface {} --protocol tcp '
+                    '--tcp-flags SYN,RST SYN --jump TCPMSS --set-mss {} >&/dev/null'.format(target, intf, mss))
 
     return None
 
diff --git a/src/conf_mode/flow_accounting_conf.py b/src/conf_mode/flow_accounting_conf.py
index b040c8b64..1008f3fae 100755
--- a/src/conf_mode/flow_accounting_conf.py
+++ b/src/conf_mode/flow_accounting_conf.py
@@ -16,7 +16,7 @@
 
 import os
 import re
-import subprocess
+import ipaddress
 
 from ipaddress import ip_address
 from jinja2 import FileSystemLoader, Environment
@@ -26,6 +26,8 @@ from vyos.ifconfig import Interface
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import cmd
+
 
 # default values
 default_sflow_server_port = 6343
@@ -80,11 +82,7 @@ def _iptables_get_nflog():
     for iptables_variant in ['iptables', 'ip6tables']:
         # run iptables, save output and split it by lines
         iptables_command = "sudo {0} -t {1} -S {2}".format(iptables_variant, iptables_nflog_table, iptables_nflog_chain)
-        process = subprocess.Popen(iptables_command, stdout=subprocess.PIPE, shell=True, universal_newlines=True)
-        stdout, stderr = process.communicate()
-        if not process.returncode == 0:
-            print("Failed to get flows list: command \"{}\" returned exit code: {}\nError: {}".format(command, process.returncode, stderr))
-            exit(1)
+        cmd(iptables_command, universal_newlines=True, message='Failed to get flows list')
         iptables_out = stdout.splitlines()
 
         # parse each line and add information to list
@@ -113,10 +111,17 @@ def _iptables_config(configured_ifaces):
     # compare current active list with configured one and delete excessive interfaces, add missed
     active_nflog_ifaces = []
     for rule in active_nflog_rules:
-        if rule['interface'] not in configured_ifaces:
-            iptable_commands.append("sudo {0} -t {1} -D {2}".format(rule['iptables_variant'], rule['table'], rule['rule_definition']))
+        iptables = rule['iptables_variant']
+        interface = rule['interface']
+        if interface not in configured_ifaces:
+            table = rule['table']
+            rule = rule['rule_definition']
+            iptable_commands.append(f'sudo {iptables} -t {table} -D {rule}')
         else:
-            active_nflog_ifaces.append({ 'iface': rule['interface'], 'iptables_variant': rule['iptables_variant'] })
+            active_nflog_ifaces.append({
+                'iface': interface,
+                'iptables_variant': iptables,
+            })
 
     # do not create new rules for already configured interfaces
     for iface in active_nflog_ifaces:
@@ -125,14 +130,14 @@ def _iptables_config(configured_ifaces):
 
     # create missed rules
     for iface_extended in configured_ifaces_extended:
-        rule_definition = "{0} -i {1} -m comment --comment FLOW_ACCOUNTING_RULE -j NFLOG --nflog-group 2 --nflog-size {2} --nflog-threshold 100".format(iptables_nflog_chain, iface_extended['iface'], default_captured_packet_size)
-        iptable_commands.append("sudo {0} -t {1} -I {2}".format(iface_extended['iptables_variant'], iptables_nflog_table, rule_definition))
+        iface = iface_extended['iface']
+        iptables = iface_extended['iptables_variant']
+        rule_definition = f'{iptables_nflog_chain} -i {iface} -m comment --comment FLOW_ACCOUNTING_RULE -j NFLOG --nflog-group 2 --nflog-size {default_captured_packet_size} --nflog-threshold 100'
+        iptable_commands.append(f'sudo {iptables} -t {iptables_nflog_table} -I {rule_definition}')
 
     # change iptables
     for command in iptable_commands:
-        return_code = subprocess.call(command.split(' '))
-        if not return_code == 0:
-            raise ConfigError("Failed to run command: {}\nExit code {}".format(command, return_code))
+        cmd(command, raising=ConfigError)
 
 
 def get_config():
@@ -351,9 +356,7 @@ def apply(config):
         command = '/usr/bin/sudo /bin/systemctl restart uacctd'
 
     # run command to start or stop flow-accounting
-    return_code = subprocess.call(command.split(' '))
-    if not return_code == 0:
-        raise ConfigError("Failed to start/stop flow-accounting: command {} returned exit code {}".format(command, return_code))
+    cmd(command, raising=ConfigError, message='Failed to start/stop flow-accounting')
 
     # configure iptables rules for defined interfaces
     if config['interfaces']:
diff --git a/src/conf_mode/host_name.py b/src/conf_mode/host_name.py
index 47cf232e9..690d1e030 100755
--- a/src/conf_mode/host_name.py
+++ b/src/conf_mode/host_name.py
@@ -25,7 +25,6 @@ import re
 import sys
 import copy
 import glob
-import subprocess
 import argparse
 import jinja2
 
@@ -34,6 +33,7 @@ import vyos.hostsd_client
 
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import cmd, run
 
 
 default_config_data = {
@@ -156,21 +156,22 @@ def apply(config):
 
     # rsyslog runs into a race condition at boot time with systemd
     # restart rsyslog only if the hostname changed.
-    hostname_old = subprocess.check_output(['hostnamectl', '--static']).decode().strip()
-
-    os.system("hostnamectl set-hostname --static {0}".format(hostname_new))
+    hostname_old = cmd('hostnamectl --static')
+    cmd(f'hostnamectl set-hostname --static {hostname_new}')
 
     # Restart services that use the hostname
     if hostname_new != hostname_old:
-        os.system("systemctl restart rsyslog.service")
+        run("systemctl restart rsyslog.service")
 
     # If SNMP is running, restart it too
-    if os.system("pgrep snmpd > /dev/null") == 0:
-        os.system("systemctl restart snmpd.service")
+    ret = run("pgrep snmpd > /dev/null")
+    if ret == 0:
+        run("systemctl restart snmpd.service")
 
     # restart pdns if it is used
-    if os.system("/usr/bin/rec_control ping >/dev/null 2>&1") == 0:
-        os.system("/etc/init.d/pdns-recursor restart >/dev/null")
+    ret = run('/usr/bin/rec_control ping >/dev/null 2>&1')
+    if ret == 0:
+        run('/etc/init.d/pdns-recursor restart >/dev/null')
 
     return None
 
diff --git a/src/conf_mode/http-api.py b/src/conf_mode/http-api.py
index 0c2e029e9..91b8aa34b 100755
--- a/src/conf_mode/http-api.py
+++ b/src/conf_mode/http-api.py
@@ -18,13 +18,13 @@
 
 import sys
 import os
-import subprocess
 import json
 from copy import deepcopy
 
 import vyos.defaults
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import cmd, run
 
 config_file = '/etc/vyos/http-api.conf'
 
@@ -91,16 +91,12 @@ def generate(http_api):
 
 def apply(http_api):
     if http_api is not None:
-        os.system('sudo systemctl restart vyos-http-api.service')
+        run('sudo systemctl restart vyos-http-api.service')
     else:
-        os.system('sudo systemctl stop vyos-http-api.service')
+        run('sudo systemctl stop vyos-http-api.service')
 
     for dep in dependencies:
-        cmd = '{0}/{1}'.format(vyos_conf_scripts_dir, dep)
-        try:
-            subprocess.check_call(cmd, shell=True)
-        except subprocess.CalledProcessError as err:
-            raise ConfigError("{}.".format(err))
+        cmd(f'{vyos_conf_scripts_dir}/{dep}', raising=ConfigError)
 
 if __name__ == '__main__':
     try:
diff --git a/src/conf_mode/https.py b/src/conf_mode/https.py
index 83a5f3602..e46f1a4e7 100755
--- a/src/conf_mode/https.py
+++ b/src/conf_mode/https.py
@@ -26,6 +26,8 @@ import vyos.certbot_util
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = '/etc/nginx/sites-available/default'
 
@@ -144,9 +146,9 @@ def generate(https):
 
 def apply(https):
     if https is not None:
-        os.system('sudo systemctl restart nginx.service')
+        run('sudo systemctl restart nginx.service')
     else:
-        os.system('sudo systemctl stop nginx.service')
+        run('sudo systemctl stop nginx.service')
 
 if __name__ == '__main__':
     try:
diff --git a/src/conf_mode/igmp_proxy.py b/src/conf_mode/igmp_proxy.py
index aa46f2c4e..abe473530 100755
--- a/src/conf_mode/igmp_proxy.py
+++ b/src/conf_mode/igmp_proxy.py
@@ -24,6 +24,8 @@ from netifaces import interfaces
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/igmpproxy.conf'
 
@@ -129,11 +131,11 @@ def generate(igmp_proxy):
 def apply(igmp_proxy):
     if igmp_proxy is None or igmp_proxy['disable']:
          # IGMP Proxy support is removed in the commit
-         os.system('sudo systemctl stop igmpproxy.service')
+         run('sudo systemctl stop igmpproxy.service')
          if os.path.exists(config_file):
              os.unlink(config_file)
     else:
-        os.system('systemctl restart igmpproxy.service')
+        run('systemctl restart igmpproxy.service')
 
     return None
 
diff --git a/src/conf_mode/intel_qat.py b/src/conf_mode/intel_qat.py
index a1abd5e81..cc7d4a915 100755
--- a/src/conf_mode/intel_qat.py
+++ b/src/conf_mode/intel_qat.py
@@ -19,10 +19,10 @@
 import sys
 import os
 import re
-import subprocess
 
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import popen, run
 
 # Define for recovering
 gl_ipsec_conf = None
@@ -49,13 +49,10 @@ def get_config():
 
 # Control configured VPN service which can use QAT
 def vpn_control(action):
+  # XXX: Should these commands report failure
   if action == 'restore' and gl_ipsec_conf:
-    ret = subprocess.Popen(['sudo', 'ipsec', 'start'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-    (output, err) = ret.communicate()
-    return
-
-  ret = subprocess.Popen(['sudo', 'ipsec', action], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-  (output, err) = ret.communicate()
+    return run('sudo ipsec start')
+  return run(f'sudo ipsec {action}')
 
 def verify(c):
   # Check if QAT service installed
@@ -66,10 +63,9 @@ def verify(c):
     return
 
   # Check if QAT device exist
-  ret = subprocess.Popen(['sudo', 'lspci',  '-nn'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-  (output, err) = ret.communicate()
+  output, err = popen('sudo lspci -nn', decode='utf-8')
   if not err:
-    data = re.findall('(8086:19e2)|(8086:37c8)|(8086:0435)|(8086:6f54)', output.decode("utf-8"))
+    data = re.findall('(8086:19e2)|(8086:37c8)|(8086:0435)|(8086:6f54)', output)
     #If QAT devices found
     if not data:
       print("\t No QAT acceleration device found")
@@ -82,17 +78,13 @@ def apply(c):
 
   # Disable QAT service
   if c['qat_conf'] == None:
-    ret = subprocess.Popen(['sudo', '/etc/init.d/vyos-qat-utilities', 'stop'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-    (output, err) = ret.communicate()
+    run('sudo /etc/init.d/vyos-qat-utilities stop')
     if c['ipsec_conf']:
       vpn_control('start')
-
     return
 
   # Run qat init.d script
-  ret = subprocess.Popen(['sudo', '/etc/init.d/vyos-qat-utilities', 'start'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-  (output, err) = ret.communicate()
-
+  run('sudo /etc/init.d/vyos-qat-utilities start')
   if c['ipsec_conf']:
     # Recovery VPN service
     vpn_control('start')
diff --git a/src/conf_mode/interfaces-bonding.py b/src/conf_mode/interfaces-bonding.py
index cc119b91a..19f43f725 100755
--- a/src/conf_mode/interfaces-bonding.py
+++ b/src/conf_mode/interfaces-bonding.py
@@ -25,6 +25,8 @@ from vyos.ifconfig_vlan import apply_vlan_config, verify_vlan_config
 from vyos.configdict import list_diff, vlan_to_dict
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import run
+
 
 default_config_data = {
     'address': [],
@@ -90,7 +92,7 @@ def get_config():
     if not os.path.isfile('/sys/class/net/bonding_masters'):
         import syslog
         syslog.syslog(syslog.LOG_NOTICE, "loading bonding kernel module")
-        if os.system('modprobe bonding max_bonds=0 miimon=250') != 0:
+        if run('modprobe bonding max_bonds=0 miimon=250') != 0:
             syslog.syslog(syslog.LOG_NOTICE, "failed loading bonding kernel module")
             raise ConfigError("failed loading bonding kernel module")
 
diff --git a/src/conf_mode/interfaces-l2tpv3.py b/src/conf_mode/interfaces-l2tpv3.py
index af1d3f482..4b5fc8306 100755
--- a/src/conf_mode/interfaces-l2tpv3.py
+++ b/src/conf_mode/interfaces-l2tpv3.py
@@ -22,6 +22,7 @@ from copy import deepcopy
 from vyos.config import Config
 from vyos.ifconfig import L2TPv3If, Interface
 from vyos import ConfigError
+from vyos.util import run
 from netifaces import interfaces
 
 default_config_data = {
@@ -50,7 +51,7 @@ def check_kmod():
     modules = ['l2tp_eth', 'l2tp_netlink', 'l2tp_ip', 'l2tp_ip6']
     for module in modules:
         if not os.path.exists(f'/sys/module/{module}'):
-            if os.system(f'modprobe {module}') != 0:
+            if run(f'modprobe {module}') != 0:
                 raise ConfigError(f'Loading Kernel module {module} failed')
 
 def get_config():
diff --git a/src/conf_mode/interfaces-openvpn.py b/src/conf_mode/interfaces-openvpn.py
index faaee9ac0..1fe1143cd 100755
--- a/src/conf_mode/interfaces-openvpn.py
+++ b/src/conf_mode/interfaces-openvpn.py
@@ -25,14 +25,13 @@ from grp import getgrnam
 from ipaddress import ip_address,ip_network,IPv4Interface
 from netifaces import interfaces
 from pwd import getpwnam
-from subprocess import Popen, PIPE
 from time import sleep
 from shutil import rmtree
 
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos.ifconfig import VTunIf
-from vyos.util import process_running
+from vyos.util import process_running, cmd
 from vyos.validate import is_addr_assigned
 from vyos import ConfigError
 
@@ -96,9 +95,6 @@ default_config_data = {
     'gid': group,
 }
 
-def subprocess_cmd(command):
-    p = Popen(command, stdout=PIPE, shell=True)
-    p.communicate()
 
 def get_config_name(intf):
     cfg_file = r'/opt/vyatta/etc/openvpn/openvpn-{}.conf'.format(intf)
@@ -744,12 +740,12 @@ def apply(openvpn):
     # 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 process_running(pidfile):
-        cmd = 'start-stop-daemon'
-        cmd += ' --stop '
-        cmd += ' --quiet'
-        cmd += ' --oknodo'
-        cmd += ' --pidfile ' + pidfile
-        subprocess_cmd(cmd)
+        command = 'start-stop-daemon'
+        command += ' --stop '
+        command += ' --quiet'
+        command += ' --oknodo'
+        command += ' --pidfile ' + pidfile
+        cmd(command)
 
     # cleanup old PID file
     if os.path.isfile(pidfile):
@@ -780,19 +776,19 @@ def apply(openvpn):
 
     # No matching OpenVPN process running - maybe it got killed or none
     # existed - nevertheless, spawn new OpenVPN process
-    cmd = 'start-stop-daemon'
-    cmd += ' --start '
-    cmd += ' --quiet'
-    cmd += ' --oknodo'
-    cmd += ' --pidfile ' + pidfile
-    cmd += ' --exec /usr/sbin/openvpn'
+    command = 'start-stop-daemon'
+    command += ' --start '
+    command += ' --quiet'
+    command += ' --oknodo'
+    command += ' --pidfile ' + pidfile
+    command += ' --exec /usr/sbin/openvpn'
     # now pass arguments to openvpn binary
-    cmd += ' --'
-    cmd += ' --daemon openvpn-' + openvpn['intf']
-    cmd += ' --config ' + get_config_name(openvpn['intf'])
+    command += ' --'
+    command += ' --daemon openvpn-' + openvpn['intf']
+    command += ' --config ' + get_config_name(openvpn['intf'])
 
     # execute assembled command
-    subprocess_cmd(cmd)
+    cmd(command)
 
     # better late then sorry ... but we can only set interface alias after
     # OpenVPN has been launched and created the interface
diff --git a/src/conf_mode/interfaces-pppoe.py b/src/conf_mode/interfaces-pppoe.py
index a396af4ea..407547175 100755
--- a/src/conf_mode/interfaces-pppoe.py
+++ b/src/conf_mode/interfaces-pppoe.py
@@ -24,7 +24,7 @@ from netifaces import interfaces
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos.ifconfig import Interface
-from vyos.util import chown_file, chmod_x, subprocess_cmd
+from vyos.util import chown_file, chmod_x, cmd
 from vyos import ConfigError
 
 default_config_data = {
@@ -182,8 +182,7 @@ def generate(pppoe):
             os.mkdir(dirname)
 
     # Always hang-up PPPoE connection prior generating new configuration file
-    cmd = f'systemctl stop ppp@{intf}.service'
-    subprocess_cmd(cmd)
+    cmd(f'systemctl stop ppp@{intf}.service')
 
     if pppoe['deleted']:
         # Delete PPP configuration files
@@ -238,8 +237,7 @@ def apply(pppoe):
     if not pppoe['disable']:
         # "dial" PPPoE connection
         intf = pppoe['intf']
-        cmd = f'systemctl start ppp@{intf}.service'
-        subprocess_cmd(cmd)
+        cmd(f'systemctl start ppp@{intf}.service')
 
         # make logfile owned by root / vyattacfg
         chown_file(pppoe['logfile'], 'root', 'vyattacfg')
diff --git a/src/conf_mode/interfaces-wireguard.py b/src/conf_mode/interfaces-wireguard.py
index 5c0c07dc4..4fa0dd8c0 100755
--- a/src/conf_mode/interfaces-wireguard.py
+++ b/src/conf_mode/interfaces-wireguard.py
@@ -17,7 +17,6 @@
 import sys
 import os
 import re
-import subprocess
 
 from copy import deepcopy
 from netifaces import interfaces
@@ -25,27 +24,26 @@ from netifaces import interfaces
 from vyos import ConfigError
 from vyos.config import Config
 from vyos.configdict import list_diff
+from vyos.util import run
 from vyos.ifconfig import WireGuardIf
 
 kdir = r'/config/auth/wireguard'
 
 def _check_kmod():
     if not os.path.exists('/sys/module/wireguard'):
-        if os.system('modprobe wireguard') != 0:
+        if run('modprobe wireguard') != 0:
             raise ConfigError("modprobe wireguard failed")
 
 
 def _migrate_default_keys():
-    if os.path.exists('{}/private.key'.format(kdir)) and not os.path.exists('{}/default/private.key'.format(kdir)):
+    if os.path.exists(f'{kdir}/private.key') and not os.path.exists(f'{kdir}/default/private.key'):
         old_umask = os.umask(0o027)
-        location = '{}/default'.format(kdir)
-        subprocess.call(['sudo mkdir -p ' + location], shell=True)
-        subprocess.call(['sudo chgrp vyattacfg ' + location], shell=True)
-        subprocess.call(['sudo chmod 750 ' + location], shell=True)
-        os.rename('{}/private.key'.format(kdir),
-                  '{}/private.key'.format(location))
-        os.rename('{}/public.key'.format(kdir),
-                  '{}/public.key'.format(location))
+        location = f'{kdir}/default'
+        run(f'sudo mkdir -p {location}')
+        run(f'sudo chgrp vyattacfg {location}')
+        run(f'sudo chmod 750 {location}')
+        os.rename(f'{kdir}/private.key', f'{location}/private.key')
+        os.rename(f'{kdir}/public.key', f'{location}/public.key')
         os.umask(old_umask)
 
 
@@ -208,8 +206,8 @@ def apply(c):
                 if re.search("DEVTYPE=wireguard", buf, re.I | re.M):
                     wg_intf = re.sub("INTERFACE=", "", re.search(
                         "INTERFACE=.*", buf, re.I | re.M).group(0))
-                    subprocess.call(
-                        ['ip l d dev ' + wg_intf + ' >/dev/null'], shell=True)
+                    # XXX: we are ignoring any errors here
+                    run(f'ip l d dev {wg_intf} >/dev/null')
         return None
 
     # init wg class
diff --git a/src/conf_mode/interfaces-wireless.py b/src/conf_mode/interfaces-wireless.py
index da8470f7e..188d0ee22 100755
--- a/src/conf_mode/interfaces-wireless.py
+++ b/src/conf_mode/interfaces-wireless.py
@@ -21,7 +21,6 @@ from re import findall
 from copy import deepcopy
 from jinja2 import FileSystemLoader, Environment
 
-from subprocess import Popen, PIPE
 from netifaces import interfaces
 from netaddr import EUI, mac_unix_expanded
 
@@ -30,7 +29,7 @@ from vyos.configdict import list_diff, vlan_to_dict
 from vyos.defaults import directories as vyos_data_dir
 from vyos.ifconfig import WiFiIf
 from vyos.ifconfig_vlan import apply_vlan_config, verify_vlan_config
-from vyos.util import process_running, chmod_x, chown_file
+from vyos.util import process_running, chmod_x, chown_file, run
 from vyos import ConfigError
 
 user = 'root'
@@ -152,9 +151,6 @@ def get_wpa_suppl_config_name(intf):
     cfg_file = cfg_dir + r'/{}.cfg'.format(intf)
     return cfg_file
 
-def subprocess_cmd(command):
-    p = Popen(command, stdout=PIPE, shell=True)
-    p.communicate()
 
 def get_config():
     wifi = deepcopy(default_config_data)
@@ -631,22 +627,22 @@ def generate(wifi):
     # always stop hostapd service first before reconfiguring it
     pidfile = get_pid('hostapd', wifi['intf'])
     if process_running(pidfile):
-        cmd = 'start-stop-daemon'
-        cmd += ' --stop '
-        cmd += ' --quiet'
-        cmd += ' --oknodo'
-        cmd += ' --pidfile ' + pidfile
-        subprocess_cmd(cmd)
+        command = 'start-stop-daemon'
+        command += ' --stop '
+        command += ' --quiet'
+        command += ' --oknodo'
+        command += ' --pidfile ' + pidfile
+        run(command)
 
     # always stop wpa_supplicant service first before reconfiguring it
     pidfile = get_pid('wpa_supplicant', wifi['intf'])
     if process_running(pidfile):
-        cmd = 'start-stop-daemon'
-        cmd += ' --stop '
-        cmd += ' --quiet'
-        cmd += ' --oknodo'
-        cmd += ' --pidfile ' + pidfile
-        subprocess_cmd(cmd)
+        command = 'start-stop-daemon'
+        command += ' --stop '
+        command += ' --quiet'
+        command += ' --oknodo'
+        command += ' --pidfile ' + pidfile
+        run(command)
 
     # Delete config files if interface is removed
     if wifi['deleted']:
@@ -807,37 +803,38 @@ def apply(wifi):
             # Physical interface is now configured. Proceed by starting hostapd or
             # wpa_supplicant daemon. When type is monitor we can just skip this.
             if wifi['op_mode'] == 'ap':
-                cmd  = 'start-stop-daemon'
-                cmd += ' --start '
-                cmd += ' --quiet'
-                cmd += ' --oknodo'
-                cmd += ' --pidfile ' + get_pid('hostapd', wifi['intf'])
-                cmd += ' --exec /usr/sbin/hostapd'
+                command = 'start-stop-daemon'
+                command += ' --start '
+                command += ' --quiet'
+                command += ' --oknodo'
+                command += ' --pidfile ' + get_pid('hostapd', wifi['intf'])
+                command += ' --exec /usr/sbin/hostapd'
                 # now pass arguments to hostapd binary
-                cmd += ' -- '
-                cmd += ' -B'
-                cmd += ' -P ' + get_pid('hostapd', wifi['intf'])
-                cmd += ' ' + get_conf_file('hostapd', wifi['intf'])
+                command += ' -- '
+                command += ' -B'
+                command += ' -P ' + get_pid('hostapd', wifi['intf'])
+                command += ' ' + get_conf_file('hostapd', wifi['intf'])
 
                 # execute assembled command
-                subprocess_cmd(cmd)
+                run(command)
 
             elif wifi['op_mode'] == 'station':
-                cmd  = 'start-stop-daemon'
-                cmd += ' --start '
-                cmd += ' --quiet'
-                cmd += ' --oknodo'
-                cmd += ' --pidfile ' + get_pid('hostapd', wifi['intf'])
-                cmd += ' --exec /sbin/wpa_supplicant'
+                command = 'start-stop-daemon'
+                command += ' --start '
+                command += ' --quiet'
+                command += ' --oknodo'
+                command += ' --pidfile ' + get_pid('hostapd', wifi['intf'])
+                command += ' --exec /sbin/wpa_supplicant'
                 # now pass arguments to hostapd binary
-                cmd += ' -- '
-                cmd += ' -s -B -D nl80211'
-                cmd += ' -P ' + get_pid('wpa_supplicant', wifi['intf'])
-                cmd += ' -i ' + wifi['intf']
-                cmd += ' -c ' + get_conf_file('wpa_supplicant', wifi['intf'])
+                command += ' -- '
+                command += ' -s -B -D nl80211'
+                command += ' -P ' + get_pid('wpa_supplicant', wifi['intf'])
+                command += ' -i ' + wifi['intf']
+                command += ' -c ' + \
+                    get_conf_file('wpa_supplicant', wifi['intf'])
 
                 # execute assembled command
-                subprocess_cmd(cmd)
+                run(command)
 
     return None
 
diff --git a/src/conf_mode/interfaces-wirelessmodem.py b/src/conf_mode/interfaces-wirelessmodem.py
index da33d54e4..5e10cfce7 100755
--- a/src/conf_mode/interfaces-wirelessmodem.py
+++ b/src/conf_mode/interfaces-wirelessmodem.py
@@ -23,7 +23,7 @@ from netifaces import interfaces
 
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
-from vyos.util import chown_file, chmod_x, subprocess_cmd
+from vyos.util import chown_file, chmod_x, cmd, run
 from vyos import ConfigError
 
 default_config_data = {
@@ -48,7 +48,7 @@ def check_kmod():
     modules = ['option', 'usb_wwan', 'usbserial']
     for module in modules:
         if not os.path.exists(f'/sys/module/{module}'):
-            if os.system(f'modprobe {module}') != 0:
+            if run(f'modprobe {module}') != 0:
                 raise ConfigError(f'Loading Kernel module {module} failed')
 
 def get_config():
@@ -156,8 +156,7 @@ def generate(wwan):
             os.mkdir(dirname)
 
     # Always hang-up WWAN connection prior generating new configuration file
-    cmd = f'systemctl stop ppp@{intf}.service'
-    subprocess_cmd(cmd)
+    cmd(f'systemctl stop ppp@{intf}.service')
 
     if wwan['deleted']:
         # Delete PPP configuration files
@@ -211,9 +210,7 @@ def apply(wwan):
     if not wwan['disable']:
         # "dial" WWAN connection
         intf = wwan['intf']
-        cmd = f'systemctl start ppp@{intf}.service'
-        subprocess_cmd(cmd)
-
+        cmd(f'systemctl start ppp@{intf}.service')
         # make logfile owned by root / vyattacfg
         chown_file(wwan['logfile'], 'root', 'vyattacfg')
 
diff --git a/src/conf_mode/ipsec-settings.py b/src/conf_mode/ipsec-settings.py
index 90b6b0d57..c2f5c8e07 100755
--- a/src/conf_mode/ipsec-settings.py
+++ b/src/conf_mode/ipsec-settings.py
@@ -24,6 +24,7 @@ from sys import exit
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
 
 ra_conn_name = "remote-access"
 charon_conf_file = "/etc/strongswan.d/charon.conf"
@@ -98,7 +99,7 @@ def get_config():
 
 ### Remove config from file by delimiter
 def remove_confs(delim_begin, delim_end, conf_file):
-    os.system("sed -i '/"+delim_begin+"/,/"+delim_end+"/d' "+conf_file)
+    run("sed -i '/"+delim_begin+"/,/"+delim_end+"/d' "+conf_file)
 
 
 ### Checking certificate storage and notice if certificate not in /config directory
@@ -111,7 +112,7 @@ def check_cert_file_store(cert_name, file_path, dts_path):
     else:
       ### Cpy file to /etc/ipsec.d/certs/ /etc/ipsec.d/cacerts/
       # todo make check
-      ret = os.system('cp -f '+file_path+' '+dts_path)
+      ret = run('cp -f '+file_path+' '+dts_path)
       if ret:
          raise ConfigError("L2TP VPN configuration error: Cannot copy "+file_path)
 
@@ -192,12 +193,12 @@ def generate(data):
         remove_confs(delim_ipsec_l2tp_begin, delim_ipsec_l2tp_end, ipsec_conf_flie)
 
 def restart_ipsec():
-    os.system('ipsec restart >&/dev/null')
+    run('ipsec restart >&/dev/null')
     # counter for apply swanctl config
     counter = 10
     while counter <= 10:
         if os.path.exists(charon_pidfile):
-            os.system('swanctl -q >&/dev/null')
+            run('swanctl -q >&/dev/null')
             break
         counter -=1
         sleep(1)
diff --git a/src/conf_mode/le_cert.py b/src/conf_mode/le_cert.py
index c657098e1..a4dbecbaa 100755
--- a/src/conf_mode/le_cert.py
+++ b/src/conf_mode/le_cert.py
@@ -18,11 +18,12 @@
 
 import sys
 import os
-import subprocess
 
 import vyos.defaults
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import cmd, run
+
 
 vyos_conf_scripts_dir = vyos.defaults.directories['conf_mode']
 
@@ -45,9 +46,9 @@ def request_certbot(cert):
 
     certbot_cmd = 'certbot certonly -n --nginx --agree-tos --no-eff-email --expand {0} {1}'.format(email_flag, domain_flag)
 
-    completed = subprocess.run(certbot_cmd, shell=True)
-
-    return completed.returncode
+    cmd(certbot_cmd,
+        raising=ConfigError,
+        message="The certbot request failed for the specified domains.")
 
 def get_config():
     conf = Config()
@@ -84,28 +85,21 @@ def generate(cert):
 
     # certbot will attempt to reload nginx, even with 'certonly';
     # start nginx if not active
-    ret = os.system('systemctl is-active --quiet nginx.ervice')
+    ret = run('systemctl is-active --quiet nginx.ervice')
     if ret:
-        os.system('sudo systemctl start nginx.service')
+        run('sudo systemctl start nginx.service')
 
-    ret = request_certbot(cert)
-    if ret:
-        raise ConfigError("The certbot request failed for the"
-                          " specified domains.")
+    request_certbot(cert)
 
 def apply(cert):
     if cert is not None:
-        os.system('sudo systemctl restart certbot.timer')
+        run('sudo systemctl restart certbot.timer')
     else:
-        os.system('sudo systemctl stop certbot.timer')
+        run('sudo systemctl stop certbot.timer')
         return None
 
     for dep in dependencies:
-        cmd = '{0}/{1}'.format(vyos_conf_scripts_dir, dep)
-        try:
-            subprocess.check_call(cmd, shell=True)
-        except subprocess.CalledProcessError as err:
-            raise ConfigError(str(err))
+        cmd(f'{vyos_conf_scripts_dir}/{dep}', raising=ConfigError)
 
 if __name__ == '__main__':
     try:
diff --git a/src/conf_mode/lldp.py b/src/conf_mode/lldp.py
index 4e3dfc0b6..c090bba83 100755
--- a/src/conf_mode/lldp.py
+++ b/src/conf_mode/lldp.py
@@ -26,6 +26,8 @@ from vyos.validate import is_addr_assigned,is_loopback_addr
 from vyos.defaults import directories as vyos_data_dir
 from vyos.version import get_version_data
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = "/etc/default/lldpd"
 vyos_config_file = "/etc/lldpd.d/01-vyos.conf"
@@ -239,10 +241,10 @@ def generate(lldp):
 def apply(lldp):
     if lldp:
         # start/restart lldp service
-        os.system('sudo systemctl restart lldpd.service')
+        run('sudo systemctl restart lldpd.service')
     else:
         # LLDP service has been terminated
-        os.system('sudo systemctl stop lldpd.service')
+        run('sudo systemctl stop lldpd.service')
         os.unlink(config_file)
         os.unlink(vyos_config_file)
 
diff --git a/src/conf_mode/mdns_repeater.py b/src/conf_mode/mdns_repeater.py
index f738cc6a6..2bccd9153 100755
--- a/src/conf_mode/mdns_repeater.py
+++ b/src/conf_mode/mdns_repeater.py
@@ -24,6 +24,8 @@ from netifaces import ifaddresses, AF_INET
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/default/mdns-repeater'
 
@@ -94,11 +96,11 @@ def generate(mdns):
 
 def apply(mdns):
     if (mdns is None) or mdns['disabled']:
-        os.system('sudo systemctl stop mdns-repeater')
+        run('sudo systemctl stop mdns-repeater')
         if os.path.exists(config_file):
             os.unlink(config_file)
     else:
-        os.system('sudo systemctl restart mdns-repeater')
+        run('sudo systemctl restart mdns-repeater')
 
     return None
 
diff --git a/src/conf_mode/ntp.py b/src/conf_mode/ntp.py
index 0f635556b..998022a8c 100755
--- a/src/conf_mode/ntp.py
+++ b/src/conf_mode/ntp.py
@@ -24,6 +24,8 @@ from sys import exit
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/ntp.conf'
 
@@ -112,10 +114,10 @@ def generate(ntp):
 
 def apply(ntp):
     if ntp is not None:
-        os.system('sudo systemctl restart ntp.service')
+        run('sudo systemctl restart ntp.service')
     else:
         # NTP support is removed in the commit
-        os.system('sudo systemctl stop ntp.service')
+        run('sudo systemctl stop ntp.service')
         os.unlink(config_file)
 
     return None
diff --git a/src/conf_mode/protocols_bfd.py b/src/conf_mode/protocols_bfd.py
index 9940c80c5..52a9e54c2 100755
--- a/src/conf_mode/protocols_bfd.py
+++ b/src/conf_mode/protocols_bfd.py
@@ -24,6 +24,8 @@ from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos.validate import is_ipv6_link_local, is_ipv6
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/tmp/bfd.frr'
 
@@ -205,7 +207,16 @@ def apply(bfd):
     if bfd is None:
         return None
 
+<<<<<<< HEAD
     os.system(f'vtysh -d bfdd -f {config_file}')
+=======
+    tmpl = jinja2.Template(config_tmpl)
+    config_text = tmpl.render(bfd)
+    with open(config_file, 'w') as f:
+        f.write(config_text)
+
+    run("sudo vtysh -d bfdd -f " + config_file)
+>>>>>>> util: T2226: covert most calls from os.system to util
     if os.path.exists(config_file):
         os.remove(config_file)
 
diff --git a/src/conf_mode/protocols_igmp.py b/src/conf_mode/protocols_igmp.py
index 0148b5dac..6e819a15a 100755
--- a/src/conf_mode/protocols_igmp.py
+++ b/src/conf_mode/protocols_igmp.py
@@ -23,6 +23,8 @@ from sys import exit
 from vyos import ConfigError
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
+from vyos.util import run
+
 
 config_file = r'/tmp/igmp.frr'
 
@@ -103,7 +105,7 @@ def apply(igmp):
         return None
 
     if os.path.exists(config_file):
-        os.system("sudo vtysh -d pimd -f " + config_file)
+        run("sudo vtysh -d pimd -f " + config_file)
         os.remove(config_file)
 
     return None
diff --git a/src/conf_mode/protocols_mpls.py b/src/conf_mode/protocols_mpls.py
index 514fe5efb..6e5d08397 100755
--- a/src/conf_mode/protocols_mpls.py
+++ b/src/conf_mode/protocols_mpls.py
@@ -21,11 +21,13 @@ from jinja2 import FileSystemLoader, Environment
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/tmp/ldpd.frr'
 
 def sysctl(name, value):
-    os.system('sysctl -wq {}={}'.format(name, value))
+    run('sysctl -wq {}={}'.format(name, value))
 
 def get_config():
     conf = Config()
@@ -160,7 +162,7 @@ def apply(mpls):
     operate_mpls_on_intfc(diactive_ifaces, 0)
 
     if os.path.exists(config_file):
-        os.system("sudo vtysh -d ldpd -f " + config_file)
+        run("sudo vtysh -d ldpd -f " + config_file)
         os.remove(config_file)
 
     return None
diff --git a/src/conf_mode/protocols_pim.py b/src/conf_mode/protocols_pim.py
index 7b360d62c..0e22d3a6b 100755
--- a/src/conf_mode/protocols_pim.py
+++ b/src/conf_mode/protocols_pim.py
@@ -23,6 +23,8 @@ from sys import exit
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/tmp/pimd.frr'
 
@@ -130,7 +132,11 @@ def apply(pim):
         return None
 
     if os.path.exists(config_file):
+<<<<<<< HEAD
         os.system("vtysh -d pimd -f " + config_file)
+=======
+        run("sudo vtysh -d pimd -f " + config_file)
+>>>>>>> util: T2226: covert most calls from os.system to util
         os.remove(config_file)
 
     return None
diff --git a/src/conf_mode/salt-minion.py b/src/conf_mode/salt-minion.py
index bc1767454..bd1d44bc8 100755
--- a/src/conf_mode/salt-minion.py
+++ b/src/conf_mode/salt-minion.py
@@ -26,6 +26,8 @@ from urllib3 import PoolManager
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/salt/minion'
 
@@ -124,10 +126,10 @@ def generate(salt):
 
 def apply(salt):
     if salt is not None:
-        os.system("sudo systemctl restart salt-minion")
+        run("sudo systemctl restart salt-minion")
     else:
         # Salt access is removed in the commit
-        os.system("sudo systemctl stop salt-minion")
+        run("sudo systemctl stop salt-minion")
         os.unlink(config_file)
 
     return None
diff --git a/src/conf_mode/service-ipoe.py b/src/conf_mode/service-ipoe.py
index dd9616a62..5bd4aea2e 100755
--- a/src/conf_mode/service-ipoe.py
+++ b/src/conf_mode/service-ipoe.py
@@ -16,7 +16,6 @@
 
 import os
 import re
-import subprocess
 
 from jinja2 import FileSystemLoader, Environment
 from socket import socket, AF_INET, SOCK_STREAM
@@ -26,6 +25,7 @@ from time import sleep
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
 
 ipoe_cnf_dir = r'/etc/accel-ppp/ipoe'
 ipoe_cnf = ipoe_cnf_dir + r'/ipoe.config'
@@ -64,15 +64,8 @@ def _chk_con():
                 break
 
 
-def _accel_cmd(cmd=''):
-    if not cmd:
-        return None
-    try:
-        ret = subprocess.check_output(
-            ['/usr/bin/accel-cmd', '-p', cmd_port, cmd]).decode().strip()
-        return ret
-    except:
-        return 1
+def _accel_cmd(command):
+    return run('/usr/bin/accel-cmd -p {cmd_port} {command}')
 
 ##### Inline functions end ####
 
@@ -306,8 +299,7 @@ def apply(c):
         return None
 
     if not os.path.exists(pidfile):
-        ret = subprocess.call(
-            ['/usr/sbin/accel-pppd', '-c', ipoe_cnf, '-p', pidfile, '-d'])
+        ret = run(f'/usr/sbin/accel-pppd -c {ipoe_cnf} -p {pidfile} -d')
         _chk_con()
         if ret != 0 and os.path.exists(pidfile):
             os.remove(pidfile)
diff --git a/src/conf_mode/service-pppoe.py b/src/conf_mode/service-pppoe.py
index afcc5ba99..d3fc82406 100755
--- a/src/conf_mode/service-pppoe.py
+++ b/src/conf_mode/service-pppoe.py
@@ -16,7 +16,6 @@
 
 import os
 import re
-import subprocess
 
 from jinja2 import FileSystemLoader, Environment
 from socket import socket, AF_INET, SOCK_STREAM
@@ -26,6 +25,7 @@ from time import sleep
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
 
 pidfile = r'/var/run/accel_pppoe.pid'
 pppoe_cnf_dir = r'/etc/accel-ppp/pppoe'
@@ -57,15 +57,8 @@ def _chk_con():
                 raise("failed to start pppoe server")
 
 
-def _accel_cmd(cmd=''):
-    if not cmd:
-        return None
-    try:
-        ret = subprocess.check_output(
-            ['/usr/bin/accel-cmd', cmd]).decode().strip()
-        return ret
-    except:
-        return 1
+def _accel_cmd(command):
+    return run(f'/usr/bin/accel-cmd {command}')
 
 
 def get_config():
@@ -426,8 +419,7 @@ def apply(c):
         return None
 
     if not os.path.exists(pidfile):
-        ret = subprocess.call(
-            ['/usr/sbin/accel-pppd', '-c', pppoe_conf, '-p', pidfile, '-d'])
+        ret = run(f'/usr/sbin/accel-pppd -c {pppoe_conf} -p {pidfile} -d')
         _chk_con()
         if ret != 0 and os.path.exists(pidfile):
             os.remove(pidfile)
diff --git a/src/conf_mode/service-router-advert.py b/src/conf_mode/service-router-advert.py
index 38c5cb2dc..0173b7242 100755
--- a/src/conf_mode/service-router-advert.py
+++ b/src/conf_mode/service-router-advert.py
@@ -23,6 +23,8 @@ from sys import exit
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/radvd.conf'
 
@@ -156,13 +158,13 @@ def generate(rtradv):
 def apply(rtradv):
     if not rtradv['interfaces']:
         # bail out early - looks like removal from running config
-        os.system('systemctl stop radvd.service')
+        run('systemctl stop radvd.service')
         if os.path.exists(config_file):
             os.unlink(config_file)
 
         return None
 
-    os.system('systemctl restart radvd.service')
+    run('systemctl restart radvd.service')
     return None
 
 if __name__ == '__main__':
diff --git a/src/conf_mode/snmp.py b/src/conf_mode/snmp.py
index ed8c1d7e1..414236c88 100755
--- a/src/conf_mode/snmp.py
+++ b/src/conf_mode/snmp.py
@@ -27,6 +27,8 @@ from vyos.defaults import directories as vyos_data_dir
 from vyos.validate import is_ipv4, is_addr_assigned
 from vyos.version import get_version_data
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file_client  = r'/etc/snmp/snmp.conf'
 config_file_daemon  = r'/etc/snmp/snmpd.conf'
@@ -507,7 +509,7 @@ def generate(snmp):
     #
     # As we are manipulating the snmpd user database we have to stop it first!
     # This is even save if service is going to be removed
-    os.system("systemctl stop snmpd.service")
+    run('systemctl stop snmpd.service')
     config_files = [config_file_client, config_file_daemon, config_file_access,
                     config_file_user]
     for file in config_files:
@@ -552,7 +554,7 @@ def apply(snmp):
         return None
 
     # start SNMP daemon
-    os.system("systemctl restart snmpd.service")
+    run("systemctl restart snmpd.service")
 
     # Passwords are not available immediately in the configuration file,
     # after daemon startup - we wait until they have been processed by
@@ -593,15 +595,15 @@ def apply(snmp):
 
                 # Now update the running configuration
                 #
-                # Currently when executing os.system() the environment does not
+                # Currently when executing run() the environment does not
                 # have the vyos_libexec_dir variable set, see Phabricator T685.
-                os.system('/opt/vyatta/sbin/my_set service snmp v3 user "{0}" auth encrypted-key "{1}" > /dev/null'.format(cfg['user'], cfg['auth_pw']))
-                os.system('/opt/vyatta/sbin/my_set service snmp v3 user "{0}" privacy encrypted-key "{1}" > /dev/null'.format(cfg['user'], cfg['priv_pw']))
-                os.system('/opt/vyatta/sbin/my_delete service snmp v3 user "{0}" auth plaintext-key > /dev/null'.format(cfg['user']))
-                os.system('/opt/vyatta/sbin/my_delete service snmp v3 user "{0}" privacy plaintext-key > /dev/null'.format(cfg['user']))
+                run('/opt/vyatta/sbin/my_set service snmp v3 user "{0}" auth encrypted-key "{1}" > /dev/null'.format(cfg['user'], cfg['auth_pw']))
+                run('/opt/vyatta/sbin/my_set service snmp v3 user "{0}" privacy encrypted-key "{1}" > /dev/null'.format(cfg['user'], cfg['priv_pw']))
+                run('/opt/vyatta/sbin/my_delete service snmp v3 user "{0}" auth plaintext-key > /dev/null'.format(cfg['user']))
+                run('/opt/vyatta/sbin/my_delete service snmp v3 user "{0}" privacy plaintext-key > /dev/null'.format(cfg['user']))
 
     # Enable AgentX in FRR
-    os.system('vtysh -c "configure terminal" -c "agentx" >/dev/null')
+    run('vtysh -c "configure terminal" -c "agentx" >/dev/null')
 
     return None
 
diff --git a/src/conf_mode/ssh.py b/src/conf_mode/ssh.py
index 014045796..a85dcd7f2 100755
--- a/src/conf_mode/ssh.py
+++ b/src/conf_mode/ssh.py
@@ -21,6 +21,8 @@ from sys import exit
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/ssh/sshd_config'
 
@@ -131,10 +133,10 @@ def generate(ssh):
 
 def apply(ssh):
     if ssh is not None and 'port' in ssh.keys():
-        os.system("sudo systemctl restart ssh.service")
+        run("sudo systemctl restart ssh.service")
     else:
         # SSH access is removed in the commit
-        os.system("sudo systemctl stop ssh.service")
+        run("sudo systemctl stop ssh.service")
         if os.path.isfile(config_file):
             os.unlink(config_file)
 
diff --git a/src/conf_mode/system-ip.py b/src/conf_mode/system-ip.py
index 335507411..66f563939 100755
--- a/src/conf_mode/system-ip.py
+++ b/src/conf_mode/system-ip.py
@@ -20,6 +20,8 @@ from sys import exit
 from copy import deepcopy
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import run
+
 
 default_config_data = {
     'arp_table': 8192,
@@ -29,7 +31,7 @@ default_config_data = {
 }
 
 def sysctl(name, value):
-    os.system('sysctl -wq {}={}'.format(name, value))
+    run('sysctl -wq {}={}'.format(name, value))
 
 def get_config():
     ip_opt = deepcopy(default_config_data)
diff --git a/src/conf_mode/system-ipv6.py b/src/conf_mode/system-ipv6.py
index bd28ec357..4e3de6fe9 100755
--- a/src/conf_mode/system-ipv6.py
+++ b/src/conf_mode/system-ipv6.py
@@ -21,6 +21,8 @@ from sys import exit
 from copy import deepcopy
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import run
+
 
 ipv6_disable_file = '/etc/modprobe.d/vyos_disable_ipv6.conf'
 
@@ -35,7 +37,7 @@ default_config_data = {
 }
 
 def sysctl(name, value):
-    os.system('sysctl -wq {}={}'.format(name, value))
+    run('sysctl -wq {}={}'.format(name, value))
 
 def get_config():
     ip_opt = deepcopy(default_config_data)
diff --git a/src/conf_mode/system-login.py b/src/conf_mode/system-login.py
index 7acb0a9a2..7c99fce39 100755
--- a/src/conf_mode/system-login.py
+++ b/src/conf_mode/system-login.py
@@ -20,13 +20,13 @@ from jinja2 import FileSystemLoader, Environment
 from psutil import users
 from pwd import getpwall, getpwnam
 from stat import S_IRUSR, S_IWUSR, S_IRWXU, S_IRGRP, S_IXGRP
-from subprocess import Popen, PIPE, STDOUT
 from sys import exit
 
 from vyos.config import Config
 from vyos.configdict import list_diff
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import cmd, run
 
 radius_config_file = "/etc/pam_radius_auth.conf"
 
@@ -52,10 +52,7 @@ def get_local_users():
 
 
 def get_crypt_pw(password):
-    command = '/usr/bin/mkpasswd --method=sha-512 {}'.format(password)
-    p = Popen(command, stdout=PIPE, stderr=STDOUT, shell=True)
-    tmp = p.communicate()[0].strip()
-    return tmp.decode()
+    return cmd(f'/usr/bin/mkpasswd --method=sha-512 {password}')
 
 
 def get_config():
@@ -210,8 +207,8 @@ def generate(login):
 
             # remove old plaintext password
             # and set new encrypted password
-            os.system("vyos_libexec_dir=/usr/libexec/vyos /opt/vyatta/sbin/my_set system login user '{}' authentication plaintext-password '' >/dev/null".format(user['name']))
-            os.system("vyos_libexec_dir=/usr/libexec/vyos /opt/vyatta/sbin/my_set system login user '{}' authentication encrypted-password '{}' >/dev/null".format(user['name'], user['password_encrypted']))
+            run("vyos_libexec_dir=/usr/libexec/vyos /opt/vyatta/sbin/my_set system login user '{}' authentication plaintext-password '' >/dev/null".format(user['name']))
+            run("vyos_libexec_dir=/usr/libexec/vyos /opt/vyatta/sbin/my_set system login user '{}' authentication encrypted-password '{}' >/dev/null".format(user['name'], user['password_encrypted']))
 
     if len(login['radius_server']) > 0:
         # Prepare Jinja2 template loader from files
@@ -238,27 +235,27 @@ def apply(login):
     for user in login['add_users']:
         # make new user using vyatta shell and make home directory (-m),
         # default group of 100 (users)
-        cmd = "useradd -m -N"
+        command = "useradd -m -N"
         # check if user already exists:
         if user['name'] in get_local_users():
             # update existing account
-            cmd = "usermod"
+            command = "usermod"
 
         # we need to use '' quotes when passing formatted data to the shell
         # else it will not work as some data parts are lost in translation
-        cmd += " -p '{}'".format(user['password_encrypted'])
-        cmd += " -s /bin/vbash"
+        command += " -p '{}'".format(user['password_encrypted'])
+        command += " -s /bin/vbash"
         if user['full_name']:
-            cmd += " -c '{}'".format(user['full_name'])
+            command += " -c '{}'".format(user['full_name'])
 
         if user['home_dir']:
-            cmd += " -d '{}'".format(user['home_dir'])
+            command += " -d '{}'".format(user['home_dir'])
 
-        cmd += " -G frrvty,vyattacfg,sudo,adm,dip,disk"
-        cmd += " {}".format(user['name'])
+        command += " -G frrvty,vyattacfg,sudo,adm,dip,disk"
+        command += " {}".format(user['name'])
 
         try:
-            os.system(cmd)
+            run(command)
 
             uid = getpwnam(user['name']).pw_uid
             gid = getpwnam(user['name']).pw_gid
@@ -298,10 +295,10 @@ def apply(login):
             # Logout user if he is logged in
             if user in list(set([tmp[0] for tmp in users()])):
                 print('{} is logged in, forcing logout'.format(user))
-                os.system('pkill -HUP -u {}'.format(user))
+                run('pkill -HUP -u {}'.format(user))
 
             # Remove user account but leave home directory to be safe
-            os.system('userdel -r {} 2>/dev/null'.format(user))
+            run('userdel -r {} 2>/dev/null'.format(user))
 
         except Exception as e:
             raise ConfigError('Deleting user "{}" raised an exception: {}'.format(user, e))
@@ -312,10 +309,10 @@ def apply(login):
     if len(login['radius_server']) > 0:
         try:
             # Enable RADIUS in PAM
-            os.system("DEBIAN_FRONTEND=noninteractive pam-auth-update --package --enable radius")
+            run("DEBIAN_FRONTEND=noninteractive pam-auth-update --package --enable radius")
 
             # Make NSS system aware of RADIUS, too
-            cmd = "sed -i -e \'/\smapname/b\' \
+            command = "sed -i -e \'/\smapname/b\' \
                           -e \'/^passwd:/s/\s\s*/&mapuid /\' \
                           -e \'/^passwd:.*#/s/#.*/mapname &/\' \
                           -e \'/^passwd:[^#]*$/s/$/ mapname &/\' \
@@ -323,7 +320,7 @@ def apply(login):
                           -e \'/^group:[^#]*$/s/: */&mapname /\' \
                           /etc/nsswitch.conf"
 
-            os.system(cmd)
+            run(command)
 
         except Exception as e:
             raise ConfigError('RADIUS configuration failed: {}'.format(e))
@@ -331,15 +328,15 @@ def apply(login):
     else:
         try:
             # Disable RADIUS in PAM
-            os.system("DEBIAN_FRONTEND=noninteractive pam-auth-update --package --remove radius")
+            run("DEBIAN_FRONTEND=noninteractive pam-auth-update --package --remove radius")
 
-            cmd = "sed -i -e \'/^passwd:.*mapuid[ \t]/s/mapuid[ \t]//\' \
+            command = "sed -i -e \'/^passwd:.*mapuid[ \t]/s/mapuid[ \t]//\' \
                    -e \'/^passwd:.*[ \t]mapname/s/[ \t]mapname//\' \
                    -e \'/^group:.*[ \t]mapname/s/[ \t]mapname//\' \
                    -e \'s/[ \t]*$//\' \
                    /etc/nsswitch.conf"
 
-            os.system(cmd)
+            run(command)
 
         except Exception as e:
             raise ConfigError('Removing RADIUS configuration failed'.format(e))
diff --git a/src/conf_mode/system-options.py b/src/conf_mode/system-options.py
index a893e98b3..063a82463 100755
--- a/src/conf_mode/system-options.py
+++ b/src/conf_mode/system-options.py
@@ -20,6 +20,7 @@ from sys import exit
 from copy import deepcopy
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import run
 
 systemd_ctrl_alt_del = '/lib/systemd/system/ctrl-alt-del.target'
 
@@ -51,9 +52,9 @@ def generate(opt):
 def apply(opt):
     # Beep action
     if opt['beep_if_fully_booted']:
-        os.system('systemctl enable vyos-beep.service >/dev/null 2>&1')
+        run('systemctl enable vyos-beep.service >/dev/null 2>&1')
     else:
-        os.system('systemctl disable vyos-beep.service >/dev/null 2>&1')
+        run('systemctl disable vyos-beep.service >/dev/null 2>&1')
 
     # Ctrl-Alt-Delete action
     if opt['ctrl_alt_del'] == 'ignore':
diff --git a/src/conf_mode/system-syslog.py b/src/conf_mode/system-syslog.py
index 8c0a6629c..25b9b5bed 100755
--- a/src/conf_mode/system-syslog.py
+++ b/src/conf_mode/system-syslog.py
@@ -22,8 +22,8 @@ from sys import exit
 
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
-from vyos.util import subprocess_cmd
 from vyos import ConfigError
+from vyos.util import run
 
 def get_config():
     c = Config()
@@ -253,10 +253,8 @@ def verify(c):
 
 def apply(c):
     if not c:
-        subprocess_cmd('systemctl stop syslog')
-        return None
-
-    subprocess_cmd('systemctl restart syslog')
+        return run('systemctl stop syslog')
+    return run('systemctl restart syslog')
 
 if __name__ == '__main__':
     try:
diff --git a/src/conf_mode/system-timezone.py b/src/conf_mode/system-timezone.py
index d715bd27e..2f8dc9e89 100755
--- a/src/conf_mode/system-timezone.py
+++ b/src/conf_mode/system-timezone.py
@@ -20,6 +20,8 @@ import os
 from copy import deepcopy
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import run
+
 
 default_config_data = {
     'name': 'UTC'
@@ -40,9 +42,7 @@ def generate(tz):
     pass
 
 def apply(tz):
-    cmd = '/usr/bin/timedatectl set-timezone {}'.format(tz['name'])
-    os.system(cmd)
-    pass
+    run('/usr/bin/timedatectl set-timezone {}'.format(tz['name']))
 
 if __name__ == '__main__':
     try:
diff --git a/src/conf_mode/tftp_server.py b/src/conf_mode/tftp_server.py
index fe2da8455..df8155084 100755
--- a/src/conf_mode/tftp_server.py
+++ b/src/conf_mode/tftp_server.py
@@ -27,6 +27,8 @@ from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos.validate import is_ipv4, is_addr_assigned
 from vyos import ConfigError
+from vyos.util import run
+
 
 config_file = r'/etc/default/tftpd'
 
@@ -113,7 +115,7 @@ def generate(tftpd):
 
 def apply(tftpd):
     # stop all services first - then we will decide
-    os.system('systemctl stop tftpd@{0..20}')
+    run('systemctl stop tftpd@{0..20}')
 
     # bail out early - e.g. service deletion
     if tftpd is None:
@@ -138,7 +140,7 @@ def apply(tftpd):
 
     idx = 0
     for listen in tftpd['listen']:
-        os.system('systemctl restart tftpd@{0}.service'.format(idx))
+        run('systemctl restart tftpd@{0}.service'.format(idx))
         idx = idx + 1
 
     return None
diff --git a/src/conf_mode/vpn-pptp.py b/src/conf_mode/vpn-pptp.py
index b1204a505..45b2c4b40 100755
--- a/src/conf_mode/vpn-pptp.py
+++ b/src/conf_mode/vpn-pptp.py
@@ -16,7 +16,6 @@
 
 import os
 import re
-import subprocess
 
 from jinja2 import FileSystemLoader, Environment
 from socket import socket, AF_INET, SOCK_STREAM
@@ -26,6 +25,7 @@ from time import sleep
 from vyos.config import Config
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
 
 pidfile = r'/var/run/accel_pptp.pid'
 pptp_cnf_dir = r'/etc/accel-ppp/pptp'
@@ -50,17 +50,9 @@ def _chk_con():
                 raise("failed to start pptp server")
                 break
 
-# chap_secrets file if auth mode local
 
-def _accel_cmd(cmd=''):
-    if not cmd:
-        return None
-    try:
-        ret = subprocess.check_output(
-            ['/usr/bin/accel-cmd', '-p', '2003', cmd]).decode().strip()
-        return ret
-    except:
-        return 1
+def _accel_cmd(command):
+    return run('/usr/bin/accel-cmd -p 2003 {command}')
 
 ###
 # inline helper functions end
@@ -256,8 +248,7 @@ def apply(c):
         return None
 
     if not os.path.exists(pidfile):
-        ret = subprocess.call(
-            ['/usr/sbin/accel-pppd', '-c', pptp_conf, '-p', pidfile, '-d'])
+        ret = run(f'/usr/sbin/accel-pppd -c {pptp_conf} -p {pidfile} -d')
         _chk_con()
         if ret != 0 and os.path.exists(pidfile):
             os.remove(pidfile)
diff --git a/src/conf_mode/vpn_sstp.py b/src/conf_mode/vpn_sstp.py
index 66b1822df..ca0844c50 100755
--- a/src/conf_mode/vpn_sstp.py
+++ b/src/conf_mode/vpn_sstp.py
@@ -18,16 +18,16 @@ import os
 
 from time import sleep
 from sys import exit
-from subprocess import check_output
 from socket import socket, AF_INET, SOCK_STREAM
 from copy import deepcopy
 from stat import S_IRUSR, S_IWUSR, S_IRGRP
 from jinja2 import FileSystemLoader, Environment
 
 from vyos.config import Config
-from vyos.defaults import directories as vyos_data_dir
-from vyos.util import process_running, subprocess_cmd
 from vyos import ConfigError
+from vyos.defaults import directories as vyos_data_dir
+from vyos.util import process_running
+from vyos.util import process_running, cmd, run
 
 pidfile = r'/var/run/accel_sstp.pid'
 sstp_cnf_dir = r'/etc/accel-ppp/sstp'
@@ -53,16 +53,9 @@ def chk_con():
                 raise("failed to start sstp server")
                 break
 
-def accel_cmd(cmd):
-    if not cmd:
-        return None
-
-    try:
-        ret = check_output(['/usr/bin/accel-cmd', '-p', '2005', cmd])
-        return ret.decode().strip()
 
-    except:
-        return 1
+def _accel_cmd(command):
+    return run(f'/usr/bin/accel-cmd -p 2005 {command}')
 
 default_config_data = {
     'local_users' : [],
@@ -363,12 +356,12 @@ def generate(sstp):
 def apply(sstp):
     if sstp is None:
         if process_running(pidfile):
-            cmd = 'start-stop-daemon'
-            cmd += ' --stop '
-            cmd += ' --quiet'
-            cmd += ' --oknodo'
-            cmd += ' --pidfile ' + pidfile
-            subprocess_cmd(cmd)
+            command = 'start-stop-daemon'
+            command += ' --stop '
+            command += ' --quiet'
+            command += ' --oknodo'
+            command += ' --pidfile ' + pidfile
+            cmd(command)
 
         if os.path.exists(pidfile):
             os.remove(pidfile)
@@ -379,23 +372,23 @@ def apply(sstp):
         if os.path.exists(pidfile):
             os.remove(pidfile)
 
-        cmd = 'start-stop-daemon'
-        cmd += ' --start '
-        cmd += ' --quiet'
-        cmd += ' --oknodo'
-        cmd += ' --pidfile ' + pidfile
-        cmd += ' --exec /usr/sbin/accel-pppd'
+        command = 'start-stop-daemon'
+        command += ' --start '
+        command += ' --quiet'
+        command += ' --oknodo'
+        command += ' --pidfile ' + pidfile
+        command += ' --exec /usr/sbin/accel-pppd'
         # now pass arguments to accel-pppd binary
-        cmd += ' --'
-        cmd += ' -c ' + sstp_conf
-        cmd += ' -p ' + pidfile
-        cmd += ' -d'
-        subprocess_cmd(cmd)
+        command += ' --'
+        command += ' -c ' + sstp_conf
+        command += ' -p ' + pidfile
+        command += ' -d'
+        cmd(command)
 
         chk_con()
 
     else:
-        accel_cmd('restart')
+        _accel_cmd('restart')
 
 
 if __name__ == '__main__':
diff --git a/src/conf_mode/vrf.py b/src/conf_mode/vrf.py
index 8cf4b72ae..07466f3aa 100755
--- a/src/conf_mode/vrf.py
+++ b/src/conf_mode/vrf.py
@@ -20,13 +20,12 @@ from sys import exit
 from copy import deepcopy
 from jinja2 import FileSystemLoader, Environment
 from json import loads
-from subprocess import check_output, CalledProcessError
 
 from vyos.config import Config
 from vyos.configdict import list_diff
 from vyos.defaults import directories as vyos_data_dir
 from vyos.ifconfig import Interface
-from vyos.util import read_file
+from vyos.util import read_file, cmd
 from vyos import ConfigError
 
 config_file = r'/etc/iproute2/rt_tables.d/vyos-vrf.conf'
@@ -40,14 +39,11 @@ default_config_data = {
 }
 
 def _cmd(command):
-    try:
-        check_output(command.split())
-    except CalledProcessError as e:
-        raise ConfigError(f'Error changing VRF: {e}')
+    cmd(command, raising=ConfigError, message='Error changing VRF')
 
 def list_rules():
     command = 'ip -j -4 rule show'
-    answer = loads(check_output(command.split()).decode())
+    answer = loads(cmd(command))
     return [_ for _ in answer if _]
 
 def vrf_interfaces(c, match):
diff --git a/src/conf_mode/vrrp.py b/src/conf_mode/vrrp.py
index 8683faca7..d3e3710d1 100755
--- a/src/conf_mode/vrrp.py
+++ b/src/conf_mode/vrrp.py
@@ -15,7 +15,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
-import subprocess
 
 from sys import exit
 from ipaddress import ip_address, ip_interface, IPv4Interface, IPv6Interface, IPv4Address, IPv6Address
@@ -28,6 +27,7 @@ import vyos.keepalived
 
 from vyos.defaults import directories as vyos_data_dir
 from vyos import ConfigError
+from vyos.util import run
 
 daemon_file = "/etc/default/keepalived"
 config_file = "/etc/keepalived/keepalived.conf"
@@ -242,17 +242,17 @@ def apply(data):
 
         if not vyos.keepalived.vrrp_running():
             print("Starting the VRRP process")
-            ret = subprocess.call("sudo systemctl restart keepalived.service", shell=True)
+            ret = run("sudo systemctl restart keepalived.service")
         else:
             print("Reloading the VRRP process")
-            ret = subprocess.call("sudo systemctl reload keepalived.service", shell=True)
+            ret = run("sudo systemctl reload keepalived.service")
 
         if ret != 0:
             raise ConfigError("keepalived failed to start")
     else:
         # VRRP is removed in the commit
         print("Stopping the VRRP process")
-        subprocess.call("sudo systemctl stop keepalived.service", shell=True)
+        run("sudo systemctl stop keepalived.service")
         os.unlink(config_file)
 
     return None
diff --git a/src/conf_mode/vyos_cert.py b/src/conf_mode/vyos_cert.py
index 4a44573ca..8b8953cb7 100755
--- a/src/conf_mode/vyos_cert.py
+++ b/src/conf_mode/vyos_cert.py
@@ -18,7 +18,6 @@
 
 import sys
 import os
-import subprocess
 import tempfile
 import pathlib
 import ssl
@@ -26,6 +25,7 @@ import ssl
 import vyos.defaults
 from vyos.config import Config
 from vyos import ConfigError
+from vyos.util import cmd
 
 vyos_conf_scripts_dir = vyos.defaults.directories['conf_mode']
 
@@ -49,16 +49,16 @@ def status_self_signed(cert_data):
     # check if certificate is 1/2 past lifetime, with openssl -checkend
     end_days = int(cert_data['lifetime'])
     end_seconds = int(0.5*60*60*24*end_days)
-    checkend_cmd = ('openssl x509 -checkend {end} -noout -in {crt}'
-                    ''.format(end=end_seconds, **cert_data))
+    checkend_cmd = 'openssl x509 -checkend {end} -noout -in {crt}'.format(end=end_seconds, **cert_data)
     try:
-        subprocess.check_call(checkend_cmd, shell=True)
+        cmd(checkend_cmd, message='Called process error')
         return True
-    except subprocess.CalledProcessError as err:
-        if err.returncode == 1:
+    except OSError as err:
+        if err.errno == 1:
             return False
-        else:
-            print("Called process error: {}.".format(err))
+        print(err)
+        # XXX: This seems wrong to continue on failure
+        # implicitely returning None
 
 def generate_self_signed(cert_data):
     san_config = None
@@ -86,9 +86,10 @@ def generate_self_signed(cert_data):
                            ''.format(**cert_data))
 
     try:
-        subprocess.check_call(openssl_req_cmd, shell=True)
-    except subprocess.CalledProcessError as err:
-        print("Called process error: {}.".format(err))
+        cmd(openssl_req_cmd, message='Called process error')
+    except OSError as err:
+        print(err)
+        # XXX: seems wrong to ignore the failure
 
     os.chmod('{key}'.format(**cert_data), 0o400)
 
@@ -126,11 +127,8 @@ def generate(vyos_cert):
 
 def apply(vyos_cert):
     for dep in dependencies:
-        cmd = '{0}/{1}'.format(vyos_conf_scripts_dir, dep)
-        try:
-            subprocess.check_call(cmd, shell=True)
-        except subprocess.CalledProcessError as err:
-            raise ConfigError("{}.".format(err))
+        command = '{0}/{1}'.format(vyos_conf_scripts_dir, dep)
+        cmd(command, raising=ConfigError)
 
 if __name__ == '__main__':
     try: