Merge pull request #2730 from vyos/mergify/bp/sagitta/pr-2729

T5474: establish common file name pattern for XML conf mode commands (backport #2729)

1 files changed, 188 insertions, 0 deletions

diff --git a/src/conf_mode/system_host-name.py b/src/conf_mode/system_host-name.py
new file mode 100755
index 000000000..6204cf247
--- /dev/null
+++ b/src/conf_mode/system_host-name.py
@@ -0,0 +1,188 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018-2023 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 or later 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 re
+import sys
+import copy
+
+import vyos.hostsd_client
+
+from vyos.base import Warning
+from vyos.config import Config
+from vyos.ifconfig import Section
+from vyos.template import is_ip
+from vyos.utils.process import cmd
+from vyos.utils.process import call
+from vyos.utils.process import process_named_running
+from vyos import ConfigError
+from vyos import airbag
+airbag.enable()
+
+default_config_data = {
+    'hostname': 'vyos',
+    'domain_name': '',
+    'domain_search': [],
+    'nameserver': [],
+    'nameservers_dhcp_interfaces': {},
+    'static_host_mapping': {}
+}
+
+hostsd_tag = 'system'
+
+def get_config(config=None):
+    if config:
+        conf = config
+    else:
+        conf = Config()
+
+    hosts = copy.deepcopy(default_config_data)
+
+    hosts['hostname'] = conf.return_value(['system', 'host-name'])
+
+    # This may happen if the config is not loaded yet,
+    # e.g. if run by cloud-init
+    if not hosts['hostname']:
+        hosts['hostname'] = default_config_data['hostname']
+
+    if conf.exists(['system', 'domain-name']):
+        hosts['domain_name'] = conf.return_value(['system', 'domain-name'])
+        hosts['domain_search'].append(hosts['domain_name'])
+
+    if conf.exists(['system', 'domain-search']):
+        for search in conf.return_values(['system', 'domain-search']):
+            hosts['domain_search'].append(search)
+
+    if conf.exists(['system', 'name-server']):
+        for ns in conf.return_values(['system', 'name-server']):
+            if is_ip(ns):
+                hosts['nameserver'].append(ns)
+            else:
+                tmp = ''
+                if_type = Section.section(ns)
+                if conf.exists(['interfaces', if_type, ns, 'address']):
+                    tmp = conf.return_values(['interfaces', if_type, ns, 'address'])
+
+                hosts['nameservers_dhcp_interfaces'].update({ ns : tmp })
+
+    # system static-host-mapping
+    for hn in conf.list_nodes(['system', 'static-host-mapping', 'host-name']):
+        hosts['static_host_mapping'][hn] = {}
+        hosts['static_host_mapping'][hn]['address'] = conf.return_values(['system', 'static-host-mapping', 'host-name', hn, 'inet'])
+        hosts['static_host_mapping'][hn]['aliases'] = conf.return_values(['system', 'static-host-mapping', 'host-name', hn, 'alias'])
+
+    return hosts
+
+
+def verify(hosts):
+    if hosts is None:
+        return None
+
+    # pattern $VAR(@) "^[[:alnum:]][-.[:alnum:]]*[[:alnum:]]$" ; "invalid host name $VAR(@)"
+    hostname_regex = re.compile("^[A-Za-z0-9][-.A-Za-z0-9]*[A-Za-z0-9]$")
+    if not hostname_regex.match(hosts['hostname']):
+        raise ConfigError('Invalid host name ' + hosts["hostname"])
+
+    # pattern $VAR(@) "^.{1,63}$" ; "invalid host-name length"
+    length = len(hosts['hostname'])
+    if length < 1 or length > 63:
+        raise ConfigError(
+            'Invalid host-name length, must be less than 63 characters')
+
+    all_static_host_mapping_addresses = []
+    # static mappings alias hostname
+    for host, hostprops in hosts['static_host_mapping'].items():
+        if not hostprops['address']:
+            raise ConfigError(f'IP address required for static-host-mapping "{host}"')
+        all_static_host_mapping_addresses.append(hostprops['address'])
+        for a in hostprops['aliases']:
+            if not hostname_regex.match(a) and len(a) != 0:
+                raise ConfigError(f'Invalid alias "{a}" in static-host-mapping "{host}"')
+
+    for interface, interface_config in hosts['nameservers_dhcp_interfaces'].items():
+        # Warnin user if interface does not have DHCP or DHCPv6 configured
+        if not set(interface_config).intersection(['dhcp', 'dhcpv6']):
+            Warning(f'"{interface}" is not a DHCP interface but uses DHCP name-server option!')
+
+    return None
+
+
+def generate(config):
+    pass
+
+def apply(config):
+    if config is None:
+        return None
+
+    ## Send the updated data to vyos-hostsd
+    try:
+        hc = vyos.hostsd_client.Client()
+
+        hc.set_host_name(config['hostname'], config['domain_name'])
+
+        hc.delete_search_domains([hostsd_tag])
+        if config['domain_search']:
+            hc.add_search_domains({hostsd_tag: config['domain_search']})
+
+        hc.delete_name_servers([hostsd_tag])
+        if config['nameserver']:
+            hc.add_name_servers({hostsd_tag: config['nameserver']})
+
+        # add our own tag's (system) nameservers and search to resolv.conf
+        hc.delete_name_server_tags_system(hc.get_name_server_tags_system())
+        hc.add_name_server_tags_system([hostsd_tag])
+
+        # this will add the dhcp client nameservers to resolv.conf
+        for intf in config['nameservers_dhcp_interfaces']:
+            hc.add_name_server_tags_system([f'dhcp-{intf}', f'dhcpv6-{intf}'])
+
+        hc.delete_hosts([hostsd_tag])
+        if config['static_host_mapping']:
+            hc.add_hosts({hostsd_tag: config['static_host_mapping']})
+
+        hc.apply()
+    except vyos.hostsd_client.VyOSHostsdError as e:
+        raise ConfigError(str(e))
+
+    ## Actually update the hostname -- vyos-hostsd doesn't do that
+
+    # No domain name -- the Debian way.
+    hostname_new = config['hostname']
+
+    # rsyslog runs into a race condition at boot time with systemd
+    # restart rsyslog only if the hostname changed.
+    hostname_old = cmd('hostnamectl --static')
+    call(f'hostnamectl set-hostname --static {hostname_new}')
+
+    # Restart services that use the hostname
+    if hostname_new != hostname_old:
+        call("systemctl restart rsyslog.service")
+
+    # If SNMP is running, restart it too
+    if process_named_running('snmpd'):
+        call('systemctl restart snmpd.service')
+
+    return None
+
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        sys.exit(1)