op-mode: T6577: create generic service restart helper to work with the APImergify/bp/circinus/pr-3817

Right now we have multiple restart helpers (e.g. dhcp server, ssh, ntp) that
all do the same (more or less):

* Check if service is configured on CLI
* Restart if configured
* Error out if unconfigured

This is not available via the op-mode API. Create a new restart.py op-mode
helper that takes the service name and possible VRF as argument so it's also
exposed via API.

(cherry picked from commit c74ae852152b0c3c3f00a1847d081d28f500e178)

1 files changed, 127 insertions, 0 deletions

diff --git a/src/op_mode/restart.py b/src/op_mode/restart.py
new file mode 100755
index 000000000..813d3a2b7
--- /dev/null
+++ b/src/op_mode/restart.py
@@ -0,0 +1,127 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2024 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import sys
+import typing
+import vyos.opmode
+
+from vyos.configquery import ConfigTreeQuery
+from vyos.utils.process import call
+from vyos.utils.commit import commit_in_progress
+
+config = ConfigTreeQuery()
+
+service_map = {
+    'dhcp' : {
+        'systemd_service': 'kea-dhcp4-server',
+        'path': ['service', 'dhcp-server'],
+    },
+    'dhcpv6' : {
+        'systemd_service': 'kea-dhcp6-server',
+        'path': ['service', 'dhcpv6-server'],
+    },
+    'dns_dynamic': {
+        'systemd_service': 'ddclient',
+        'path': ['service', 'dns', 'dynamic'],
+    },
+    'dns_forwarding': {
+        'systemd_service': 'pdns-recursor',
+        'path': ['service', 'dns', 'forwarding'],
+    },
+    'igmp_proxy': {
+        'systemd_service': 'igmpproxy',
+        'path': ['protocols', 'igmp-proxy'],
+    },
+    'ipsec': {
+        'systemd_service': 'strongswan',
+        'path': ['vpn', 'ipsec'],
+    },
+    'mdns_repeater': {
+        'systemd_service': 'avahi-daemon',
+        'path': ['service', 'mdns', 'repeater'],
+    },
+    'reverse_proxy': {
+        'systemd_service': 'haproxy',
+        'path': ['load-balancing', 'reverse-proxy'],
+    },
+    'router_advert': {
+        'systemd_service': 'radvd',
+        'path': ['service', 'router-advert'],
+    },
+    'snmp' : {
+        'systemd_service': 'snmpd',
+    },
+    'ssh' : {
+        'systemd_service': 'ssh',
+    },
+    'suricata' : {
+        'systemd_service': 'suricata',
+    },
+    'vrrp' : {
+        'systemd_service': 'keepalived',
+        'path': ['high-availability', 'vrrp'],
+    },
+    'webproxy' : {
+        'systemd_service': 'squid',
+    },
+}
+services = typing.Literal['dhcp', 'dhcpv6', 'dns_dynamic', 'dns_forwarding', 'igmp_proxy', 'ipsec', 'mdns_repeater', 'reverse_proxy', 'router_advert', 'snmp', 'ssh', 'suricata' 'vrrp', 'webproxy']
+
+def _verify(func):
+    """Decorator checks if DHCP(v6) config exists"""
+    from functools import wraps
+
+    @wraps(func)
+    def _wrapper(*args, **kwargs):
+        config = ConfigTreeQuery()
+        name = kwargs.get('name')
+        human_name = name.replace('_', '-')
+
+        if commit_in_progress():
+            print(f'Cannot restart {human_name} service while a commit is in progress')
+            sys.exit(1)
+
+        # Get optional CLI path from service_mapping dict
+        # otherwise use "service name" CLI path
+        path = ['service', name]
+        if 'path' in service_map[name]:
+            path = service_map[name]['path']
+
+        # Check if config does not exist
+        if not config.exists(path):
+            raise vyos.opmode.UnconfiguredSubsystem(f'Service {human_name} is not configured!')
+        if config.exists(path + ['disable']):
+            raise vyos.opmode.UnconfiguredSubsystem(f'Service {human_name} is disabled!')
+        return func(*args, **kwargs)
+
+    return _wrapper
+
+@_verify
+def restart_service(raw: bool, name: services, vrf: typing.Optional[str]):
+    systemd_service = service_map[name]['systemd_service']
+    if vrf:
+        call(f'systemctl restart "{systemd_service}@{vrf}.service"')
+    else:
+        call(f'systemctl restart "{systemd_service}.service"')
+
+if __name__ == '__main__':
+    try:
+        res = vyos.opmode.run(sys.modules[__name__])
+        if res:
+            print(res)
+    except (ValueError, vyos.opmode.Error) as e:
+        print(e)
+        sys.exit(1)