T1376: improve show_dhcp and show_dhcpv6

2 files changed, 155 insertions, 49 deletions

diff --git a/src/op_mode/show_dhcp.py b/src/op_mode/show_dhcp.py
index 652173dc1..c2a05f516 100755
--- a/src/op_mode/show_dhcp.py
+++ b/src/op_mode/show_dhcp.py
@@ -20,6 +20,9 @@ import argparse
 import ipaddress
 import tabulate
 import sys
+import collections
+import os
+from datetime import datetime
 
 from vyos.config import Config
 from isc_dhcp_leases import Lease, IscDhcpLeases
@@ -27,6 +30,18 @@ from isc_dhcp_leases import Lease, IscDhcpLeases
 lease_file = "/config/dhcpd.leases"
 pool_key = "shared-networkname"
 
+lease_display_fields = collections.OrderedDict()
+lease_display_fields['ip'] = 'IP address'
+lease_display_fields['hardware_address'] = 'Hardware address'
+lease_display_fields['state'] = 'State'
+lease_display_fields['start'] = 'Lease start'
+lease_display_fields['end'] = 'Lease expiration'
+lease_display_fields['remaining'] = 'Remaining'
+lease_display_fields['pool'] = 'Pool'
+lease_display_fields['hostname'] = 'Hostname'
+
+lease_valid_states = ['all', 'active', 'free', 'expired', 'released', 'abandoned', 'reset', 'backup']
+
 def in_pool(lease, pool):
     if pool_key in lease.sets:
         if lease.sets[pool_key] == pool:
@@ -34,17 +49,47 @@ def in_pool(lease, pool):
 
     return False
 
+def utc_to_local(utc_dt):
+    return datetime.fromtimestamp((utc_dt - datetime(1970,1,1)).total_seconds())
+
 def get_lease_data(lease):
     data = {}
 
-    # End time may not be present in backup leases
+    # isc-dhcp lease times are in UTC so we need to convert them to local time to display
     try:
-        data["expires"] = lease.end.strftime("%Y/%m/%d %H:%M:%S")
+        data["start"] = utc_to_local(lease.start).strftime("%Y/%m/%d %H:%M:%S")
     except:
-        data["expires"] = ""
+        data["start"] = ""
+
+    try:
+        data["end"] = utc_to_local(lease.end).strftime("%Y/%m/%d %H:%M:%S")
+    except:
+        data["end"] = ""
+
+    try:
+        data["remaining"] = lease.end - datetime.utcnow()
+        # negative timedelta prints wrong so bypass it
+        if (data["remaining"].days >= 0):
+            # substraction gives us a timedelta object which can't be formatted with strftime
+            # so we use str(), split gets rid of the microseconds
+            data["remaining"] = str(data["remaining"]).split('.')[0]
+        else:
+            data["remaining"] = ""
+    except:
+        data["remaining"] = ""
+
+    # currently not used but might come in handy
+    # todo: parse into datetime string
+    for prop in ['tstp', 'tsfp', 'atsfp', 'cltt']:
+        if prop in lease.data:
+            data[prop] = lease.data[prop]
+        else:
+            data[prop] = ''
 
     data["hardware_address"] = lease.ethernet
     data["hostname"] = lease.hostname
+
+    data["state"] = lease.binding_state
     data["ip"] = lease.ip
 
     try:
@@ -54,38 +99,53 @@ def get_lease_data(lease):
 
     return data
 
-def get_leases(leases, state=None, pool=None):
-    # define variable for leases
-    leases_dict = {}
-
+def get_leases(leases, state, pool=None, sort='ip'):
     # get leases from file
     leases = IscDhcpLeases(lease_file).get()
 
-    # convert leases list to dictionary to avoid records duplication - it's the fastest and easiest way to do this
+    # filter leases by state
+    if 'all' not in state:
+        leases = list(filter(lambda x: x.binding_state in state, leases))
+
+    # filter leases by pool name
+    if pool is not None:
+        if config.exists_effective("service dhcp-server shared-network-name {0}".format(pool)):
+            leases = list(filter(lambda x: in_pool(x, pool), leases))
+        else:
+            print("Pool {0} does not exist.".format(pool))
+            sys.exit(0)
+
+    # should maybe filter all state=active by lease.valid here?
+
+    # sort by start time to dedupe (newest lease overrides older)
+    leases = sorted(leases, key = lambda lease: lease.start)
+
+    # dedupe by converting to dict
+    leases_dict = {}
     for lease in leases:
+        # dedupe by IP
         leases_dict[lease.ip] = lease
 
-    # filter leases by state
-    if state is 'active':
-        leases = list(filter(lambda x: x.active and x.valid, leases_dict.values()))
-    if state is 'free':
-        leases = list(filter(lambda x: x.binding_state == 'free', leases_dict.values()))
+    # convert the lease data
+    leases = list(map(get_lease_data, leases_dict.values()))
 
-    # filter lease by pool name
-    if pool is not None:
-        leases = list(filter(lambda x: in_pool(x, pool), leases))
+    # apply output/display sort
+    if sort == 'ip':
+        leases = sorted(leases, key = lambda lease: int(ipaddress.ip_address(lease['ip'])))
+    else:
+        leases = sorted(leases, key = lambda lease: lease[sort])
 
-    # return sorted leases list
-    return sorted(list(map(get_lease_data, leases)), key = lambda k: k['ip'])
+    return leases
 
 def show_leases(leases):
-    headers = ["IP address", "Hardware address", "Lease expiration", "Pool", "Client Name"]
-
     lease_list = []
     for l in leases:
-        lease_list.append([l["ip"], l["hardware_address"], l["expires"], l["pool"], l["hostname"]])
+        lease_list_params = []
+        for k in lease_display_fields.keys():
+            lease_list_params.append(l[k])
+        lease_list.append(lease_list_params)
 
-    output = tabulate.tabulate(lease_list, headers)
+    output = tabulate.tabulate(lease_list, lease_display_fields.values())
 
     print(output)
 
@@ -98,7 +158,7 @@ def get_pool_size(config, pool):
             start = config.return_effective_value("service dhcp-server shared-network-name {0} subnet {1} range {2} start".format(pool, s, r))
             stop = config.return_effective_value("service dhcp-server shared-network-name {0} subnet {1} range {2} stop".format(pool, s, r))
 
-            size += int(ipaddress.IPv4Address(stop)) - int(ipaddress.IPv4Address(start))
+            size += int(ipaddress.ip_address(stop)) - int(ipaddress.ip_address(start))
 
     return size
 
@@ -114,35 +174,33 @@ if __name__ == '__main__':
     group = parser.add_mutually_exclusive_group()
     group.add_argument("-l", "--leases", action="store_true", help="Show DHCP leases")
     group.add_argument("-s", "--statistics", action="store_true", help="Show DHCP statistics")
+    group.add_argument("--allowed", type=str, choices=["pool", "sort", "state"], help="Show allowed values for argument")
 
-    parser.add_argument("-e", "--expired", action="store_true", help="Show expired leases")
-    parser.add_argument("-p", "--pool", type=str, action="store", help="Show lease for specific pool")
-    parser.add_argument("-j", "--json", action="store_true", default=False, help="Product JSON output")
+    parser.add_argument("-p", "--pool", type=str, help="Show lease for specific pool")
+    parser.add_argument("-S", "--sort", type=str, choices=lease_display_fields.keys(), default='ip', help="Sort by")
+    parser.add_argument("-t", "--state", type=str, nargs="+", choices=lease_valid_states, default="active", help="Lease state to show (can specify multiple with spaces)")
+    parser.add_argument("-j", "--json", action="store_true", default=False, help="Produce JSON output")
 
     args = parser.parse_args()
 
     # Do nothing if service is not configured
     config = Config()
     if not config.exists_effective('service dhcp-server'):
-        print("DHCP service is not configured")
+        print("DHCP service is not configured.")
         sys.exit(0)
 
+    # if dhcp server is down, inactive leases may still be shown as active, so warn the user.
+    if os.system('systemctl -q is-active isc-dhcp-server.service') != 0:
+        print("WARNING: DHCP server is configured but not started. Data may be stale.")
+
     if args.leases:
-        if args.expired:
-            if args.pool:
-                leases = get_leases(lease_file, state='free', pool=args.pool)
-            else:
-                leases = get_leases(lease_file, state='free')
-        else:
-            if args.pool:
-                leases = get_leases(lease_file, state='active', pool=args.pool)
-            else:
-                leases = get_leases(lease_file, state='active')
+        leases = get_leases(lease_file, args.state, args.pool, args.sort)
 
         if args.json:
             print(json.dumps(leases, indent=4))
         else:
             show_leases(leases)
+
     elif args.statistics:
         pools = []
 
@@ -156,7 +214,7 @@ if __name__ == '__main__':
         stats = []
         for p in pools:
             size = get_pool_size(config, p)
-            leases = len(get_leases(lease_file, state='active', pool=args.pool))
+            leases = len(get_leases(lease_file, state='active', pool=p))
 
             if size != 0:
                 use_percentage = round(leases / size * 100)
@@ -176,5 +234,12 @@ if __name__ == '__main__':
             print(json.dumps(stats, indent=4))
         else:
             show_pool_stats(stats)
+
+    elif args.allowed == 'pool':
+        print(' '.join(config.list_effective_nodes("service dhcp-server shared-network-name")))
+    elif args.allowed == 'sort':
+        print(' '.join(lease_display_fields.keys()))
+    elif args.allowed == 'state':
+        print(' '.join(lease_valid_states))
     else:
-        print("Use either --leases or --statistics option")
+        parser.print_help()
diff --git a/src/op_mode/show_dhcpv6.py b/src/op_mode/show_dhcpv6.py
index f1f5a6a55..1a6ee62e6 100755
--- a/src/op_mode/show_dhcpv6.py
+++ b/src/op_mode/show_dhcpv6.py
@@ -21,6 +21,8 @@ import ipaddress
 import tabulate
 import sys
 import collections
+import os
+from datetime import datetime
 
 from vyos.config import Config
 from isc_dhcp_leases import Lease, IscDhcpLeases
@@ -33,6 +35,7 @@ lease_display_fields['ip'] = 'IPv6 address'
 lease_display_fields['state'] = 'State'
 lease_display_fields['last_comm'] = 'Last communication'
 lease_display_fields['expires'] = 'Lease expiration'
+lease_display_fields['remaining'] = 'Remaining'
 lease_display_fields['type'] = 'Type'
 lease_display_fields['pool'] = 'Pool'
 lease_display_fields['iaid_duid'] = 'IAID_DUID'
@@ -57,20 +60,35 @@ def format_hex_string(in_str):
 
     return out_str
 
+def utc_to_local(utc_dt):
+    return datetime.fromtimestamp((utc_dt - datetime(1970,1,1)).total_seconds())
+
 def get_lease_data(lease):
     data = {}
 
-    # End time may not be present in backup leases
+    # isc-dhcp lease times are in UTC so we need to convert them to local time to display
     try:
-        data["expires"] = lease.end.strftime("%Y/%m/%d %H:%M:%S")
+        data["expires"] = utc_to_local(lease.end).strftime("%Y/%m/%d %H:%M:%S")
     except:
         data["expires"] = ""
 
     try:
-        data["last_comm"] = lease.last_communication.strftime("%Y/%m/%d %H:%M:%S")
+        data["last_comm"] = utc_to_local(lease.last_communication).strftime("%Y/%m/%d %H:%M:%S")
     except:
         data["last_comm"] = ""
 
+    try:
+        data["remaining"] = lease.end - datetime.utcnow()
+        # negative timedelta prints wrong so bypass it
+        if (data["remaining"].days >= 0):
+            # substraction gives us a timedelta object which can't be formatted with strftime
+            # so we use str(), split gets rid of the microseconds
+            data["remaining"] = str(data["remaining"]).split('.')[0]
+        else:
+            data["remaining"] = ""
+    except:
+        data["remaining"] = ""
+
     # isc-dhcp records lease declarations as ia_{na|ta|pd} IAID_DUID {...}
     # where IAID_DUID is the combined IAID and DUID
     data["iaid_duid"] = format_hex_string(lease.host_identifier_string)
@@ -91,16 +109,35 @@ def get_lease_data(lease):
 def get_leases(leases, state, pool=None, sort='ip'):
     leases = IscDhcpLeases(lease_file).get()
 
-    if state != 'all':
-        leases = list(filter(lambda x: x.binding_state == state, leases))
+    # filter leases by state
+    if 'all' not in state:
+        leases = list(filter(lambda x: x.binding_state in state, leases))
 
-    # filter lease by pool name
+    # filter leases by pool name
     if pool is not None:
-        leases = list(filter(lambda x: in_pool(x, pool), leases))
+        if config.exists_effective("service dhcp-server shared-network-name {0}".format(pool)):
+            leases = list(filter(lambda x: in_pool(x, pool), leases))
+        else:
+            print("Pool {0} does not exist.".format(pool))
+            sys.exit(0)
 
-    leases = list(map(get_lease_data, leases))
+    # should maybe filter all state=active by lease.valid here?
+
+    # sort by last_comm time to dedupe (newest lease overrides older)
+    leases = sorted(leases, key = lambda lease: lease.last_communication)
+
+    # dedupe by converting to dict
+    leases_dict = {}
+    for lease in leases:
+        # dedupe by IP
+        leases_dict[lease.ip] = lease
+
+    # convert the lease data
+    leases = list(map(get_lease_data, leases_dict.values()))
+
+    # apply output/display sort
     if sort == 'ip':
-        leases = sorted(leases, key = lambda k: int(ipaddress.IPv6Address(k['ip'])))
+        leases = sorted(leases, key = lambda k: int(ipaddress.ip_address(k['ip'])))
     else:
         leases = sorted(leases, key = lambda k: k[sort])
 
@@ -128,7 +165,7 @@ if __name__ == '__main__':
 
     parser.add_argument("-p", "--pool", type=str, help="Show lease for specific pool")
     parser.add_argument("-S", "--sort", type=str, choices=lease_display_fields.keys(), default='ip', help="Sort by")
-    parser.add_argument("-t", "--state", type=str, choices=lease_valid_states, default="active", help="Lease state to show")
+    parser.add_argument("-t", "--state", type=str, nargs="+", choices=lease_valid_states, default="active", help="Lease state to show (can specify multiple with spaces)")
     parser.add_argument("-j", "--json", action="store_true", default=False, help="Produce JSON output")
 
     args = parser.parse_args()
@@ -139,6 +176,10 @@ if __name__ == '__main__':
         print("DHCPv6 service is not configured")
         sys.exit(0)
 
+    # if dhcp server is down, inactive leases may still be shown as active, so warn the user.
+    if os.system('systemctl -q is-active isc-dhcpv6-server.service') != 0:
+        print("WARNING: DHCPv6 server is configured but not started. Data may be stale.")
+
     if args.leases:
         leases = get_leases(lease_file, args.state, args.pool, args.sort)