scripts/network/exdhcp: cleaned up code in dhcpd_edithosts.py

scripts/network/exdhcp/dhcpd_edithosts.py

@@ -1,4 +1,5 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
+
 # Licensed to the Apache Software Foundation (ASF) under one
 # or more contributor license agreements.  See the NOTICE file
 # distributed with this work for additional information
@@ -18,10 +19,11 @@
 
 
 # Usage: dhcpd_edithosts.py mac ip hostname dns gateway nextserver
-import sys, os
-from os.path import exists
+
+import sys
+import os
+from pathlib import Path
 from time import sleep
-from os import remove
 
 usage = '''dhcpd_edithosts.py mac ip hostname dns gateway nextserver'''
 conf_path = "/etc/dhcpd.conf"
@@ -36,62 +38,61 @@ def lock():
 			sleep(1)
 			count = count + 1
 			if count > sleep_max:
-				print "Can not get file lock at %s, time expired" % file_lock
+				print("Can not get file lock at {}, time expired".format(file_lock))
 				return False
-	
+
 	try:
-		f = open(file_lock, "w")
-		f.close()
+		f = Path(file_lock).open(mode="w")
 		return True
-	except IOError,e:
-		print "Cannot create file lock at /etc/dhcpd.conf_locked,", e
+	except IOError as e:
+		print("Cannot create file lock at /etc/dhcpd.conf_locked: {}".format(e))
 		return False
 
 
 def unlock():
 	if exists(file_lock) == False:
-		print "Cannot find %s when unlocking, race condition happens" % file_lock
+		print("Cannot find {} when unlocking, race condition happens".format(file_lock))
 	else:
 		try:
-			remove(file_lock)
+			os.remove(file_lock)
 			return True
-		except IOError, e:
-			print "Cannot remove file lock at %s" % file_lock
+		except IOError as e:
+			print("Cannot remove file lock at {0}: {1}".format(file_lock,e))
 			return False
 
 def insert_host_entry(mac, ip, hostname, dns, gateway, next_server):
 	if lock() == False:
 		return 1
 
-	cmd = 'sed -i /"fixed-address %s"/d %s' % (ip, conf_path)
+	cmd = 'sed -i /"fixed-address {0}"/d {1}'.format(ip,conf_path)
 	ret = os.system(cmd)
 	if ret != 0:
-		print "Command %s failed" % cmd
+		print("Command {} failed".format(cmd))
 		unlock()
 		return 1
 
-	cmd = 'sed -i /"hardware ethernet %s"/d %s' % (mac, conf_path)
+	cmd = 'sed -i /"hardware ethernet {0}"/d {1}'.format(mac,conf_path)
 	ret = os.system(cmd)
 	if ret != 0:
-		print "Command %s failed" % cmd
+		print("Command {} failed".format(cmd))
 		unlock()
 		return 1
 
 	if next_server != "null":
 		entry = host_entry1 % (hostname, mac, ip, dns, "cloudnine.internal", gateway, next_server)
 	else:
 		entry = host_entry % (hostname, mac, ip, dns, "cloudnine.internal", gateway)
-	cmd = '''echo '%s' >> %s''' % (entry, conf_path)
+	cmd = '''echo '{0}' >> {1}'''.format(entry,conf_path)
 	ret = os.system(cmd)
 	if ret != 0:
-		print "Command %s failed" % cmd
+		print("Command {} failed".format(cmd))
 		unlock()
 		return 1
 
 	cmd = 'service dhcpd restart'
 	ret = os.system(cmd)
 	if ret != 0:
-		print "Command %s failed" % cmd
+		print("Command {} failed".format(cmd))
 		unlock()
 		return 1
 
@@ -102,22 +103,20 @@ def insert_host_entry(mac, ip, hostname, dns, gateway, next_server):
 
 if __name__ == "__main__":
 	if len(sys.argv) < 7:
-		print usage
+		print(usage)
 		sys.exit(1)
-	
+
 	mac = sys.argv[1]
 	ip = sys.argv[2]
 	hostname = sys.argv[3]
 	dns = sys.argv[4]
 	gateway = sys.argv[5]
 	next_server = sys.argv[6]
 
-	if exists(conf_path) == False:
+	if Path(conf_path).exists() == False:
 		conf_path = "/etc/dhcp/dhcpd.conf"
-	if exists(conf_path) == False:
-		print "Cannot find dhcpd.conf"
+		print("Cannot find dhcpd.conf")
 		sys.exit(1)
 
 	ret = insert_host_entry(mac, ip, hostname, dns, gateway, next_server)
 	sys.exit(ret)
-