T3355: migrate "show dhcp client lease" to new op-mode style

vyos@vyos# ${vyos_op_scripts_dir}/dhcp.py show_client_leases --family inet --interface eth0.10
Interface    eth0.10
IP address   172.16.33.123                  [Active]
Subnet Mask  255.255.255.0
Domain Name  vyos.net
Router       172.16.33.254
Name Server  172.16.254.30
DHCP Server  172.16.33.254
DHCP Server  86400
Last Update  Sat Jul 29 21:13:32 CEST 2023
Expiry       Sun Jul 30 21:13:31 CEST 2023

vyos@vyos# ${vyos_op_scripts_dir}/dhcp.py show_client_leases --family inet --interface eth0.10 --raw
[
    {
        "last_update": "Sat Jul 29 21:13:32 CEST 2023",
        "reason": "BOUND",
        "interface": "eth0.10",
        "new_expiry": "1690744411",
        "new_dhcp_lease_time": "86400",
        "medium": "",
        "alias_ip_address": "",
        "new_ip_address": "172.16.33.123",
        "new_broadcast_address": "172.16.33.255",
        "new_subnet_mask": "255.255.255.0",
        "new_domain_name": "vyos.net",
        "new_network_number": "172.16.33.0",
        "new_domain_name_servers": "172.16.254.30",
        "new_routers": "172.16.33.254",
        "new_static_routes": "",
        "new_dhcp_server_identifier": "172.16.33.254",
        "new_dhcp_message_type": "5",
        "old_ip_address": "",
        "old_subnet_mask": "",
        "old_domain_name": "",
        "old_domain_name_servers": "",
        "old_routers": "",
        "old_static_routes": ""
    }
]

1 files changed, 77 insertions, 1 deletions

diff --git a/src/op_mode/dhcp.py b/src/op_mode/dhcp.py
index 3e51e990b..653e670c5 100755
--- a/src/op_mode/dhcp.py
+++ b/src/op_mode/dhcp.py
@@ -14,10 +14,12 @@
 # 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 os
 import sys
 import typing
 
 from datetime import datetime
+from glob import glob
 from ipaddress import ip_address
 from isc_dhcp_leases import IscDhcpLeases
 from tabulate import tabulate
@@ -27,8 +29,9 @@ import vyos.opmode
 from vyos.base import Warning
 from vyos.configquery import ConfigTreeQuery
 
-from vyos.utils.process import cmd
 from vyos.utils.dict import dict_search
+from vyos.utils.file import read_file
+from vyos.utils.process import cmd
 from vyos.utils.process import is_systemd_service_running
 
 config = ConfigTreeQuery()
@@ -287,6 +290,79 @@ def show_server_leases(raw: bool, family: ArgFamily, pool: typing.Optional[str],
         return _get_formatted_server_leases(lease_data, family=family)
 
 
+def _get_raw_client_leases(family='inet', interface=None):
+    lease_dir = '/var/lib/dhcp'
+    lease_files = []
+    lease_data = []
+
+    if interface:
+        tmp = f'{lease_dir}/dhclient_{interface}.lease'
+        if os.path.exists(tmp):
+            lease_files.append(tmp)
+    else:
+        # All DHCP leases
+        lease_files = glob(f'{lease_dir}/dhclient_*.lease')
+
+    for lease in lease_files:
+        tmp = {}
+        with open(lease, 'r') as f:
+            for line in f.readlines():
+                line = line.rstrip()
+                if 'last_update' not in tmp:
+                    tmp.update({'last_update' : line})
+                    continue
+
+                k, v = line.split('=')
+                tmp.update({k : v.replace("'", "")})
+
+        lease_data.append(tmp)
+
+    return lease_data
+
+def _get_formatted_client_leases(lease_data, family):
+    from time import localtime
+    from time import strftime
+
+    from vyos.validate import is_intf_addr_assigned
+
+    data_entries = []
+    for lease in lease_data:
+        data_entries.append(["Interface", lease['interface']])
+        if 'new_ip_address' in lease:
+            tmp = '[Active]' if is_intf_addr_assigned(lease['interface'], lease['new_ip_address']) else '[Inactive]'
+            data_entries.append(["IP address", lease['new_ip_address'], tmp])
+        if 'new_subnet_mask' in lease:
+            data_entries.append(["Subnet Mask", lease['new_subnet_mask']])
+        if 'new_domain_name' in lease:
+            data_entries.append(["Domain Name", lease['new_domain_name']])
+        if 'new_routers' in lease:
+            data_entries.append(["Router", lease['new_routers']])
+        if 'new_domain_name_servers' in lease:
+            data_entries.append(["Name Server", lease['new_domain_name_servers']])
+        if 'new_dhcp_server_identifier' in lease:
+            data_entries.append(["DHCP Server", lease['new_dhcp_server_identifier']])
+        if 'new_dhcp_lease_time' in lease:
+            data_entries.append(["DHCP Server", lease['new_dhcp_lease_time']])
+        if 'last_update' in lease:
+            data_entries.append(["Last Update", lease['last_update']])
+        if 'new_expiry' in lease:
+            tmp = strftime('%a %b %d %H:%M:%S %Z %Y', localtime(int(lease['new_expiry'])))
+            data_entries.append(["Expiry", tmp])
+
+        # Add empty marker
+        data_entries.append([''])
+
+    output = tabulate(data_entries, tablefmt='plain')
+
+    return output
+
+def show_client_leases(raw: bool, family: ArgFamily, interface: typing.Optional[str]):
+    lease_data = _get_raw_client_leases(family=family, interface=interface)
+    if raw:
+        return lease_data
+    else:
+        return _get_formatted_client_leases(lease_data, family=family)
+
 if __name__ == '__main__':
     try:
         res = vyos.opmode.run(sys.modules[__name__])