library/netfile.py - maas - Gitiles

 #!/usr/bin/env python

 # Copyright 2017-present Open Networking Foundation
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 # http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.

 import json
 import os
 import re
 import sys
 import shlex
 import string
 import ipaddress
 # WANT_JSON

 # Regular expressions to identify comments and blank lines
 comment = re.compile("^\s*#")
 blank = re.compile("^\s*$")

 #####
 # Parsers
 #
 # Parses are methods that take the form 'parse_<keyword>', where the keyword
 # is the first word on a line in file. The purpose of the parser is to
 # evaluate the line tna update the interface model accordingly.
 ####

 # Compares the current and desired network configuration to see if there
 # is a change and returns:
 # 0 if no change
 # -1 if the change has no semantic value (i.e. comments differ)
 # 1 if there is a semantic change (i.e. its meaningful)
 # the highest priority of change is returned, i.e. if there is both
 # a semantic and non-semantic change a 1 is returned indicating a
 # semantic change.
 def value_equal(left, right):
     if type(left) == type(right):
         return left == right
     return str(left) == str(right)

 def compare(have, want):
     result = 0
     for key in list(set().union(have.keys(), want.keys())):
         if key in have.keys() and key in want.keys():
             if not value_equal(have[key], want[key]):
                 if key in ["description"]:
                     result = -1
                 else:
                     return 1
         else:
             if key in ["description"]:
                 result = -1
             else:
                 return 1
     return result

 # Creates an interface definition in the model and sets the auto
 # configuration to true
 def parse_auto(data, current, words, description):
     if words[1] in data.keys():
         iface = data[words[1]]
     else:
         iface = {}

     if len(description) > 0:
         iface["description"] = description

     iface["auto"] = True
     data[words[1]] = iface
     return words[1]

 # Creates an interface definition in the model if one does not exist and
 # sets the type and configuation method
 def parse_iface(data, current, words, description):
     if words[1] in data.keys():
         iface = data[words[1]]
     else:
         iface = {}

     if len(description) > 0:
         iface["description"] = description

     iface["type"] = words[2]
     iface["config"] = words[3]
     data[words[1]] = iface
     return words[1]

 allow_lists = ["pre-up", "post-up", "pre-down", "post-down"]

 # Used to evaluate attributes and add a generic name / value pair to the interface
 # model
 def parse_add_attr(data, current, words, description):
     global allow_lists
     if current == "":
         raise SyntaxError("Attempt to add attribute '%s' without an interface" % words[0])

     if current in data.keys():
         iface = data[current]
     else:
         iface = {}

     if len(description) > 0:
         iface["description"] = description

     if words[0] in iface and words[0] in allow_lists:
         have = iface[words[0]]
         if type(have) is list:
             iface[words[0]].append(" ".join(words[1:]))
         else:
             iface[words[0]] = [have, " ".join(words[1:])]
     else:
         iface[words[0]] = " ".join(words[1:])

     data[current] = iface
     return current

 #####
 # Writers
 #
 # Writers take the form of 'write_<keyword>` where keyword is an interface
 # attribute. The role of the writer is to output the attribute to the
 # output stream, i.e. the new interface file.
 #####

 # Writes a generic name / value pair indented
 def write_attr(out, name, value):
     if isinstance(value, list):
         for line in value:
             out.write("  %s %s\n" % (name, line))
     else:
         out.write("  %s %s\n" % (name, value))

 # Writes an interface definition to the output stream
 def write_iface(out, name, iface):
     if "description" in iface.keys():
         val = iface["description"]
         if len(val) > 0 and val[0] != "#":
             val = "# " + val
         out.write("%s\n" % (val))
     if "auto" in iface.keys() and iface["auto"]:
         out.write("auto %s\n" % (name))
     out.write("iface %s %s %s\n" % (name, iface["type"], iface["config"]))
     for attr in sorted(iface.keys(), key=lambda x:x in write_sort_order.keys() and write_sort_order[x] or 100):
         if attr in write_ignore:
             continue
         writer = "write_%s" % (attr)
         if writer in all_methods:
             globals()[writer](out, attr, iface[attr])
         else:
             write_attr(out, attr, iface[attr])
     out.write("\n")

 # Writes the new interface file
 def write(out, data):
 #    out.write("# This file describes the network interfaces available on your system\n")
 #    out.write("# and how to activate them. For more information, see interfaces(5).\n\n")
     # First to loopback
     for name, iface in data.items():
         if iface["config"] != "loopback":
             continue
         write_iface(out, name, iface)

     for iface in sorted(data.keys(), key=lambda x:x in write_iface_sort_order.keys() and write_iface_sort_order[x] or x):
         if data[iface]["config"] == "loopback":
             continue
         write_iface(out, iface, data[iface])

 # The defaults for the netfile task
 src_file = "/etc/network/interfaces"
 dest_file = None
 merge_comments = False
 state = "present"
 name = ""
 force = False
 values = {
     "config": "manual",
     "type": "inet"
 }

 # read the argument string from the arguments file
 args_file = sys.argv[1]
 args_data = file(args_file).read()

 # parse the task options
 arguments = json.loads(args_data)
 for key, value in arguments.iteritems():
     if key == "src":
         src_file = value
     elif key == "dest":
         dest_file = value
     elif key == "name":
         name = value
     elif key == "state":
         state = value
     elif key == "force":
         force = value.lower() in ['true', 't', 'yes', 'y']
     elif key == "description":
         values["description"] = value
     elif key == "merge-comments":
         merge_comments = value.lower() in ['true', 't', 'yes', 'y']
     elif key == "address":
         if string.find(value, "/") != -1:
             parts = value.split('/')
             addr = ipaddress.ip_network(value, strict=False)
             values["address"] = parts[0]
             values["network"] = addr.network_address.exploded.encode('ascii','ignore')
             values["netmask"] = addr.netmask.exploded.encode('ascii','ignore')
             values["broadcast"] = addr.broadcast_address.exploded.encode('ascii','ignore')
         else:
             values["address"] = value
     elif key[0] != '_':
         values[key] = value

 # If name is not set we need to error out
 if name == "":
     result = {
         "changed": False,
         "failed": True,
         "msg": "Name is a mansitory parameter",
     }
     print json.dumps(result)
     sys.stdout.flush()
     exit(1)

 # If no destination file was specified, write it back to the same file
 if not dest_file:
     dest_file = src_file

 # all methods is used to check if parser or writer methods exist
 all_methods = dir()

 # which attributes should be ignored and not be written as single
 # attributes values against and interface
 write_ignore = ["auto", "type", "config", "description", "source"]

 # specifies the order in which attributes are written against an
 # interface. Any attribute note in this list is sorted by default
 # order after the attributes specified.
 write_sort_order = {
     "address"   :  1,
     "network"   :  2,
     "netmask"   :  3,
     "broadcast" :  4,
     "gateway"   :  5,
     "pre-up"    : 10,
     "post-up"   : 11,
     "pre-down"  : 12,
     "post-down" : 13
 }

 write_iface_sort_order = {
     "fabric" : "y",
     "mgmtbr" : "z"
 }

 # Read and parse the specified interface file
 file = open(src_file, "r")
 ifaces = {}
 current = "" # The current interface being parsed
 description = ""
 for line in file.readlines():
     line = line.rstrip('\n')

     if comment.match(line):
         if len(description) > 0:
             description = description + '\n' + line
         else:
             description = line

     if len(description) > 0 and blank.match(line):
         description = description + '\n'

     # Drop any comment of blank line
     if comment.match(line) or blank.match(line):
         continue

     # Parse the line
     words = line.split()
     parser = "parse_" + words[0].replace("-", "_")
     if parser in all_methods:
         current = globals()[parser](ifaces, current, words, description)
     else:
         current = parse_add_attr(ifaces, current, words, description)

     description = ""

 file.close()

 # Assume no change unless we discover otherwise
 result = {
     "changed" : False
 }
 change_type = 0

 # if the interface specified and state is present then either add
 # it to the model or replace it if it already exists.
 if state == "query":
     if name in ifaces.keys():
         result["interface"] = ifaces[name]
         result["found"] = True
     else:
         result["found"] = False
 elif state == "present":
     if name in ifaces.keys():
         have = ifaces[name]
         change_type = compare(have, values)
         result["change_type"] = change_type
         if change_type != 0:
             ifaces[name] = values
             if merge_comments and "description" in have.keys() and len(have["description"]) > 0:
                 result["merge_comments"] = True
                 if "description" in values.keys() and len(values["description"]) > 0:
                     ifaces[name]["description"] = values["description"] + "\n" + have["description"]
                 else:
                     ifaces[name]["description"] = have["description"]
             result["changed"] = (change_type == 1)
     else:
         ifaces[name] = values
         result["changed"] = True


 # if state is absent then remove it from the model
 elif state == "absent" and name in ifaces.keys():
     del ifaces[name]
     result["changed"] = True

 # Only write the output file if something has changed or if the
 # task requests a forced write.
 if force or result["changed"] or change_type != 0:
     file = open(dest_file, "w+")
     write(file, ifaces)
     file.close()

 # Output the task result
 print json.dumps(result)
	#!/usr/bin/env python

	# Copyright 2017-present Open Networking Foundation
	#
	# Licensed under the Apache License, Version 2.0 (the "License");
	# you may not use this file except in compliance with the License.
	# You may obtain a copy of the License at
	#
	# http://www.apache.org/licenses/LICENSE-2.0
	#
	# Unless required by applicable law or agreed to in writing, software
	# distributed under the License is distributed on an "AS IS" BASIS,
	# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	# See the License for the specific language governing permissions and
	# limitations under the License.

	import json
	import os
	import re
	import sys
	import shlex
	import string
	import ipaddress
	# WANT_JSON

	# Regular expressions to identify comments and blank lines
	comment = re.compile("^\s*#")
	blank = re.compile("^\s*$")

	#####
	# Parsers
	#
	# Parses are methods that take the form 'parse_<keyword>', where the keyword
	# is the first word on a line in file. The purpose of the parser is to
	# evaluate the line tna update the interface model accordingly.
	####

	# Compares the current and desired network configuration to see if there
	# is a change and returns:
	# 0 if no change
	# -1 if the change has no semantic value (i.e. comments differ)
	# 1 if there is a semantic change (i.e. its meaningful)
	# the highest priority of change is returned, i.e. if there is both
	# a semantic and non-semantic change a 1 is returned indicating a
	# semantic change.
	def value_equal(left, right):
	if type(left) == type(right):
	return left == right
	return str(left) == str(right)

	def compare(have, want):
	result = 0
	for key in list(set().union(have.keys(), want.keys())):
	if key in have.keys() and key in want.keys():
	if not value_equal(have[key], want[key]):
	if key in ["description"]:
	result = -1
	else:
	return 1
	else:
	if key in ["description"]:
	result = -1
	else:
	return 1
	return result

	# Creates an interface definition in the model and sets the auto
	# configuration to true
	def parse_auto(data, current, words, description):
	if words[1] in data.keys():
	iface = data[words[1]]
	else:
	iface = {}

	if len(description) > 0:
	iface["description"] = description

	iface["auto"] = True
	data[words[1]] = iface
	return words[1]

	# Creates an interface definition in the model if one does not exist and
	# sets the type and configuation method
	def parse_iface(data, current, words, description):
	if words[1] in data.keys():
	iface = data[words[1]]
	else:
	iface = {}

	if len(description) > 0:
	iface["description"] = description

	iface["type"] = words[2]
	iface["config"] = words[3]
	data[words[1]] = iface
	return words[1]

	allow_lists = ["pre-up", "post-up", "pre-down", "post-down"]

	# Used to evaluate attributes and add a generic name / value pair to the interface
	# model
	def parse_add_attr(data, current, words, description):
	global allow_lists
	if current == "":
	raise SyntaxError("Attempt to add attribute '%s' without an interface" % words[0])

	if current in data.keys():
	iface = data[current]
	else:
	iface = {}

	if len(description) > 0:
	iface["description"] = description

	if words[0] in iface and words[0] in allow_lists:
	have = iface[words[0]]
	if type(have) is list:
	iface[words[0]].append(" ".join(words[1:]))
	else:
	iface[words[0]] = [have, " ".join(words[1:])]
	else:
	iface[words[0]] = " ".join(words[1:])

	data[current] = iface
	return current

	#####
	# Writers
	#
	# Writers take the form of 'write_<keyword>` where keyword is an interface
	# attribute. The role of the writer is to output the attribute to the
	# output stream, i.e. the new interface file.
	#####

	# Writes a generic name / value pair indented
	def write_attr(out, name, value):
	if isinstance(value, list):
	for line in value:
	out.write(" %s %s\n" % (name, line))
	else:
	out.write(" %s %s\n" % (name, value))

	# Writes an interface definition to the output stream
	def write_iface(out, name, iface):
	if "description" in iface.keys():
	val = iface["description"]
	if len(val) > 0 and val[0] != "#":
	val = "# " + val
	out.write("%s\n" % (val))
	if "auto" in iface.keys() and iface["auto"]:
	out.write("auto %s\n" % (name))
	out.write("iface %s %s %s\n" % (name, iface["type"], iface["config"]))
	for attr in sorted(iface.keys(), key=lambda x:x in write_sort_order.keys() and write_sort_order[x] or 100):
	if attr in write_ignore:
	continue
	writer = "write_%s" % (attr)
	if writer in all_methods:
	globals()[writer](out, attr, iface[attr])
	else:
	write_attr(out, attr, iface[attr])
	out.write("\n")

	# Writes the new interface file
	def write(out, data):
	# out.write("# This file describes the network interfaces available on your system\n")
	# out.write("# and how to activate them. For more information, see interfaces(5).\n\n")
	# First to loopback
	for name, iface in data.items():
	if iface["config"] != "loopback":
	continue
	write_iface(out, name, iface)

	for iface in sorted(data.keys(), key=lambda x:x in write_iface_sort_order.keys() and write_iface_sort_order[x] or x):
	if data[iface]["config"] == "loopback":
	continue
	write_iface(out, iface, data[iface])

	# The defaults for the netfile task
	src_file = "/etc/network/interfaces"
	dest_file = None
	merge_comments = False
	state = "present"
	name = ""
	force = False
	values = {
	"config": "manual",
	"type": "inet"
	}

	# read the argument string from the arguments file
	args_file = sys.argv[1]
	args_data = file(args_file).read()

	# parse the task options
	arguments = json.loads(args_data)
	for key, value in arguments.iteritems():
	if key == "src":
	src_file = value
	elif key == "dest":
	dest_file = value
	elif key == "name":
	name = value
	elif key == "state":
	state = value
	elif key == "force":
	force = value.lower() in ['true', 't', 'yes', 'y']
	elif key == "description":
	values["description"] = value
	elif key == "merge-comments":
	merge_comments = value.lower() in ['true', 't', 'yes', 'y']
	elif key == "address":
	if string.find(value, "/") != -1:
	parts = value.split('/')
	addr = ipaddress.ip_network(value, strict=False)
	values["address"] = parts[0]
	values["network"] = addr.network_address.exploded.encode('ascii','ignore')
	values["netmask"] = addr.netmask.exploded.encode('ascii','ignore')
	values["broadcast"] = addr.broadcast_address.exploded.encode('ascii','ignore')
	else:
	values["address"] = value
	elif key[0] != '_':
	values[key] = value

	# If name is not set we need to error out
	if name == "":
	result = {
	"changed": False,
	"failed": True,
	"msg": "Name is a mansitory parameter",
	}
	print json.dumps(result)
	sys.stdout.flush()
	exit(1)

	# If no destination file was specified, write it back to the same file
	if not dest_file:
	dest_file = src_file

	# all methods is used to check if parser or writer methods exist
	all_methods = dir()

	# which attributes should be ignored and not be written as single
	# attributes values against and interface
	write_ignore = ["auto", "type", "config", "description", "source"]

	# specifies the order in which attributes are written against an
	# interface. Any attribute note in this list is sorted by default
	# order after the attributes specified.
	write_sort_order = {
	"address" : 1,
	"network" : 2,
	"netmask" : 3,
	"broadcast" : 4,
	"gateway" : 5,
	"pre-up" : 10,
	"post-up" : 11,
	"pre-down" : 12,
	"post-down" : 13
	}

	write_iface_sort_order = {
	"fabric" : "y",
	"mgmtbr" : "z"
	}

	# Read and parse the specified interface file
	file = open(src_file, "r")
	ifaces = {}
	current = "" # The current interface being parsed
	description = ""
	for line in file.readlines():
	line = line.rstrip('\n')

	if comment.match(line):
	if len(description) > 0:
	description = description + '\n' + line
	else:
	description = line

	if len(description) > 0 and blank.match(line):
	description = description + '\n'

	# Drop any comment of blank line
	if comment.match(line) or blank.match(line):
	continue

	# Parse the line
	words = line.split()
	parser = "parse_" + words[0].replace("-", "_")
	if parser in all_methods:
	current = globals()[parser](ifaces, current, words, description)
	else:
	current = parse_add_attr(ifaces, current, words, description)

	description = ""

	file.close()

	# Assume no change unless we discover otherwise
	result = {
	"changed" : False
	}
	change_type = 0

	# if the interface specified and state is present then either add
	# it to the model or replace it if it already exists.
	if state == "query":
	if name in ifaces.keys():
	result["interface"] = ifaces[name]
	result["found"] = True
	else:
	result["found"] = False
	elif state == "present":
	if name in ifaces.keys():
	have = ifaces[name]
	change_type = compare(have, values)
	result["change_type"] = change_type
	if change_type != 0:
	ifaces[name] = values
	if merge_comments and "description" in have.keys() and len(have["description"]) > 0:
	result["merge_comments"] = True
	if "description" in values.keys() and len(values["description"]) > 0:
	ifaces[name]["description"] = values["description"] + "\n" + have["description"]
	else:
	ifaces[name]["description"] = have["description"]
	result["changed"] = (change_type == 1)
	else:
	ifaces[name] = values
	result["changed"] = True


	# if state is absent then remove it from the model
	elif state == "absent" and name in ifaces.keys():
	del ifaces[name]
	result["changed"] = True

	# Only write the output file if something has changed or if the
	# task requests a forced write.
	if force or result["changed"] or change_type != 0:
	file = open(dest_file, "w+")
	write(file, ifaces)
	file.close()

	# Output the task result
	print json.dumps(result)