ddclient: T5791: Relocate process params to ExecStart

Pull up all the global parameters controlling
process behavior to systemd service.

Also remove `syslog=yes`` as it is not needed with
`exec` type service.

data/templates/dns-dynamic/ddclient.conf.j2

@@ -21,10 +21,7 @@ if{{ ipv }}={{ address }}, \
 {{ host }}
 {% endmacro %}
 ### Autogenerated by service_dns_dynamic.py ###
-daemon={{ interval }}
-syslog=yes
 ssl=yes
-cache={{ config_file | replace('.conf', '.cache') }}
 {# ddclient default (web=dyndns) doesn't support ssl and results in process lockup #}
 web=googledomains
 {# ddclient default (use=ip) results in confusing warning message in log #}

data/templates/dns-dynamic/override.conf.j2

@@ -1,4 +1,5 @@
 {% set vrf_command = 'ip vrf exec ' ~ vrf ~ ' ' if vrf is vyos_defined else '' %}
+{% set cache_file = config_file.replace('.conf', '.cache') %}
 [Unit]
 ConditionPathExists={{ config_file }}
 Wants=
@@ -7,5 +8,5 @@ After=vyos-router.service
 [Service]
 EnvironmentFile=
 ExecStart=
-ExecStart={{ vrf_command }}/usr/bin/ddclient --file {{ config_file }} --foreground
+ExecStart={{ vrf_command }}/usr/bin/ddclient --file {{ config_file }} --cache {{ cache_file }} --foreground --daemon {{ interval }}
 Restart=always

smoketest/scripts/cli/test_service_dns_dynamic.py

@@ -20,15 +20,18 @@
 from base_vyostest_shim import VyOSUnitTestSHIM
 
 from vyos.configsession import ConfigSessionError
+from vyos.utils.file import read_file
 from vyos.utils.process import cmd
 from vyos.utils.process import process_named_running
+from vyos.xml_ref import default_value
 
 DDCLIENT_SYSTEMD_UNIT = '/run/systemd/system/ddclient.service.d/override.conf'
 DDCLIENT_CONF = '/run/ddclient/ddclient.conf'
 DDCLIENT_PNAME = 'ddclient'
 
 base_path = ['service', 'dns', 'dynamic']
 name_path = base_path + ['name']
+default_interval = default_value(base_path + ['interval'])
 server = 'ddns.vyos.io'
 hostname = 'test.ddns.vyos.io'
 zone = 'vyos.io'
@@ -95,12 +98,14 @@ def test_01_dyndns_service_standard(self):
 
             # Check the generating config parameters
             ddclient_conf = cmd(f'sudo cat {DDCLIENT_CONF}')
-            # default value 300 seconds
-            self.assertIn(f'daemon=300', ddclient_conf)
             self.assertIn(f'usev4=ifv4', ddclient_conf)
             self.assertIn(f'ifv4={interface}', ddclient_conf)
             self.assertIn(f'password=\'{password}\'', ddclient_conf)
 
+            # Check default interval of 300 seconds
+            systemd_override = read_file(DDCLIENT_SYSTEMD_UNIT)
+            self.assertIn(f'--daemon {default_interval}', systemd_override)
+
             for opt in details.keys():
                 if opt == 'username':
                     login = details[opt]
@@ -140,7 +145,6 @@ def test_02_dyndns_service_ipv6(self):
 
         # Check the generating config parameters
         ddclient_conf = cmd(f'sudo cat {DDCLIENT_CONF}')
-        self.assertIn(f'daemon={interval}', ddclient_conf)
         self.assertIn(f'usev6=ifv6', ddclient_conf)
         self.assertIn(f'ifv6={interface}', ddclient_conf)
         self.assertIn(f'protocol={proto}', ddclient_conf)
@@ -150,6 +154,10 @@ def test_02_dyndns_service_ipv6(self):
         self.assertIn(f'min-interval={wait_time}', ddclient_conf)
         self.assertIn(f'max-interval={expiry_time_good}', ddclient_conf)
 
+        # default value 300 seconds
+        systemd_override = read_file(DDCLIENT_SYSTEMD_UNIT)
+        self.assertIn(f'--daemon {interval}', systemd_override)
+
     # IPv4+IPv6 dual DDNS service configuration
     def test_03_dyndns_service_dual_stack(self):
         services = {'cloudflare': {'protocol': 'cloudflare', 'zone': zone},
@@ -339,9 +347,10 @@ def test_08_dyndns_vrf(self):
         self.cli_commit()
 
         # Check for process in VRF
-        systemd_override = cmd(f'cat {DDCLIENT_SYSTEMD_UNIT}')
+        systemd_override = read_file(DDCLIENT_SYSTEMD_UNIT)
         self.assertIn(f'ExecStart=ip vrf exec {vrf_name} /usr/bin/ddclient ' \
-                      f'--file {DDCLIENT_CONF} --foreground', systemd_override)
+                      f'--file {DDCLIENT_CONF} --cache {DDCLIENT_CONF.replace("conf", "cache")} ' \
+                      f'--foreground --daemon {default_interval}', systemd_override)
 
         # Check for process in VRF
         proc = cmd(f'ip vrf pids {vrf_name}')