#!/usr/bin/env python3
#
# Small library and commandline tool to do logical diffs of zonefiles
# ./zonediff -h gives you help output
#
# Requires dnspython to do all the heavy lifting
#
# (c)2009 Dennis Kaarsemaker <dennis@kaarsemaker.net>
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose with or without fee is hereby granted,
# provided that the above copyright notice and this permission notice
# appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
"""See diff_zones.__doc__ for more information"""
from typing import cast, Union, Any # pylint: disable=unused-import
__all__ = ['diff_zones', 'format_changes_plain', 'format_changes_html']
try:
import dns.zone
import dns.node
except ImportError:
raise SystemExit("Please install dnspython")
def diff_zones(zone1, # type: dns.zone.Zone
zone2, # type: dns.zone.Zone
ignore_ttl=False,
ignore_soa=False
): # type: (...) -> list
"""diff_zones(zone1, zone2, ignore_ttl=False, ignore_soa=False) -> changes
Compares two dns.zone.Zone objects and returns a list of all changes
in the format (name, oldnode, newnode).
If ignore_ttl is true, a node will not be added to this list if the
only change is its TTL.
If ignore_soa is true, a node will not be added to this list if the
only changes is a change in a SOA Rdata set.
The returned nodes do include all Rdata sets, including unchanged ones.
"""
changes = []
for name in zone1:
namestr = str(name)
n1 = cast(dns.node.Node, zone1.get_node(namestr))
n2 = cast(dns.node.Node, zone2.get_node(namestr))
if not n2:
changes.append((str(name), n1, n2))
elif _nodes_differ(n1, n2, ignore_ttl, ignore_soa):
changes.append((str(name), n1, n2))
for name in zone2:
n3 = cast(dns.node.Node, zone1.get_node(name))
if not n3:
n4 = cast(dns.node.Node, zone2.get_node(name))
changes.append((str(name), n3, n4))
return changes
def _nodes_differ(n1, # type: dns.node.Node
n2, # type: dns.node.Node
ignore_ttl, # type: bool
ignore_soa # type: bool
): # type: (...) -> bool
if ignore_soa or not ignore_ttl:
# Compare datasets directly
for r in n1.rdatasets:
if ignore_soa and r.rdtype == dns.rdatatype.SOA:
continue
if r not in n2.rdatasets:
return True
if not ignore_ttl:
return r.ttl != n2.find_rdataset(r.rdclass, r.rdtype).ttl
for r in n2.rdatasets:
if ignore_soa and r.rdtype == dns.rdatatype.SOA:
continue
if r not in n1.rdatasets:
return True
assert False
else:
return n1 != n2
def format_changes_plain(oldf, # type: str
newf, # type: str
changes, # type: list
ignore_ttl=False
): # type: (...) -> str
"""format_changes(oldfile, newfile, changes, ignore_ttl=False) -> str
Given 2 filenames and a list of changes from diff_zones, produce diff-like
output. If ignore_ttl is True, TTL-only changes are not displayed"""
ret = "--- {}\n+++ {}\n".format(oldf, newf)
for name, old, new in changes:
ret += "@ %s\n" % name
if not old:
for r in new.rdatasets:
ret += "+ %s\n" % str(r).replace('\n', '\n+ ')
elif not new:
for r in old.rdatasets:
ret += "- %s\n" % str(r).replace('\n', '\n+ ')
else:
for r in old.rdatasets:
if r not in new.rdatasets or (
r.ttl != new.find_rdataset(r.rdclass, r.rdtype).ttl and
not ignore_ttl
):
ret += "- %s\n" % str(r).replace('\n', '\n+ ')
for r in new.rdatasets:
if r not in old.rdatasets or (
r.ttl != old.find_rdataset(r.rdclass, r.rdtype).ttl and
not ignore_ttl
):
ret += "+ %s\n" % str(r).replace('\n', '\n+ ')
return ret
def format_changes_html(oldf, # type: str
newf, # type: str
changes, # type: list
ignore_ttl=False
): # type: (...) -> str
"""format_changes(oldfile, newfile, changes, ignore_ttl=False) -> str
Given 2 filenames and a list of changes from diff_zones, produce nice html
output. If ignore_ttl is True, TTL-only changes are not displayed"""
ret = '''<table class="zonediff">
<thead>
<tr>
<th> </th>
<th class="old">%s</th>
<th class="new">%s</th>
</tr>
</thead>
<tbody>\n''' % (oldf, newf)
for name, old, new in changes:
ret += ' <tr class="rdata">\n <td class="rdname">%s</td>\n' % name
if not old:
for r in new.rdatasets:
ret += (
' <td class="old"> </td>\n'
' <td class="new">%s</td>\n'
) % str(r).replace('\n', '<br />')
elif not new:
for r in old.rdatasets:
ret += (
' <td class="old">%s</td>\n'
' <td class="new"> </td>\n'
) % str(r).replace('\n', '<br />')
else:
ret += ' <td class="old">'
for r in old.rdatasets:
if r not in new.rdatasets or (
r.ttl != new.find_rdataset(r.rdclass, r.rdtype).ttl and
not ignore_ttl
):
ret += str(r).replace('\n', '<br />')
ret += '</td>\n'
ret += ' <td class="new">'
for r in new.rdatasets:
if r not in old.rdatasets or (
r.ttl != old.find_rdataset(r.rdclass, r.rdtype).ttl and
not ignore_ttl
):
ret += str(r).replace('\n', '<br />')
ret += '</td>\n'
ret += ' </tr>\n'
return ret + ' </tbody>\n</table>'
# Make this module usable as a script too.
def main(): # type: () -> None
import argparse
import subprocess
import sys
import traceback
usage = """%prog zonefile1 zonefile2 - Show differences between zones in a diff-like format
%prog [--git|--bzr|--rcs] zonefile rev1 [rev2] - Show differences between two revisions of a zonefile
The differences shown will be logical differences, not textual differences.
"""
p = argparse.ArgumentParser(usage=usage)
p.add_argument('-s', '--ignore-soa', action="store_true", default=False, dest="ignore_soa",
help="Ignore SOA-only changes to records")
p.add_argument('-t', '--ignore-ttl', action="store_true", default=False, dest="ignore_ttl",
help="Ignore TTL-only changes to Rdata")
p.add_argument('-T', '--traceback', action="store_true", default=False, dest="tracebacks",
help="Show python tracebacks when errors occur")
p.add_argument('-H', '--html', action="store_true", default=False, dest="html",
help="Print HTML output")
p.add_argument('-g', '--git', action="store_true", default=False, dest="use_git",
help="Use git revisions instead of real files")
p.add_argument('-b', '--bzr', action="store_true", default=False, dest="use_bzr",
help="Use bzr revisions instead of real files")
p.add_argument('-r', '--rcs', action="store_true", default=False, dest="use_rcs",
help="Use rcs revisions instead of real files")
opts, args = p.parse_args()
opts.use_vc = opts.use_git or opts.use_bzr or opts.use_rcs
def _open(what, err): # type: (Union[list,str], str) -> Any
if isinstance(what, list):
# Must be a list, open subprocess
try:
proc = subprocess.Popen(what, stdout=subprocess.PIPE)
proc.wait()
if proc.returncode == 0:
return proc.stdout
sys.stderr.write(err + "\n")
except Exception:
sys.stderr.write(err + "\n")
if opts.tracebacks:
traceback.print_exc()
else:
# Open as normal file
try:
return open(what, 'rb')
except IOError:
sys.stderr.write(err + "\n")
if opts.tracebacks:
traceback.print_exc()
if not opts.use_vc and len(args) != 2:
p.print_help()
sys.exit(64)
if opts.use_vc and len(args) not in (2, 3):
p.print_help()
sys.exit(64)
# Open file descriptors
if not opts.use_vc:
oldn, newn = args
else:
if len(args) == 3:
filename, oldr, newr = args
oldn = "{}:{}".format(oldr, filename)
newn = "{}:{}".format(newr, filename)
else:
filename, oldr = args
newr = None
oldn = "{}:{}".format(oldr, filename)
newn = filename
old, new = None, None
oldz, newz = None, None
if opts.use_bzr:
old = _open(["bzr", "cat", "-r" + oldr, filename],
"Unable to retrieve revision {} of {}".format(oldr, filename))
if newr is not None:
new = _open(["bzr", "cat", "-r" + newr, filename],
"Unable to retrieve revision {} of {}".format(newr, filename))
elif opts.use_git:
old = _open(["git", "show", oldn],
"Unable to retrieve revision {} of {}".format(oldr, filename))
if newr is not None:
new = _open(["git", "show", newn],
"Unable to retrieve revision {} of {}".format(newr, filename))
elif opts.use_rcs:
old = _open(["co", "-q", "-p", "-r" + oldr, filename],
"Unable to retrieve revision {} of {}".format(oldr, filename))
if newr is not None:
new = _open(["co", "-q", "-p", "-r" + newr, filename],
"Unable to retrieve revision {} of {}".format(newr, filename))
if not opts.use_vc:
old = _open(oldn, "Unable to open %s" % oldn)
if not opts.use_vc or newr is None:
new = _open(newn, "Unable to open %s" % newn)
if not old or not new:
sys.exit(65)
# Parse the zones
try:
oldz = dns.zone.from_file(old, origin='.', check_origin=False)
except dns.exception.DNSException:
sys.stderr.write("Incorrect zonefile: %s\n" % old)
if opts.tracebacks:
traceback.print_exc()
try:
newz = dns.zone.from_file(new, origin='.', check_origin=False)
except dns.exception.DNSException:
sys.stderr.write("Incorrect zonefile: %s\n" % new)
if opts.tracebacks:
traceback.print_exc()
if not oldz or not newz:
sys.exit(65)
changes = diff_zones(oldz, newz, opts.ignore_ttl, opts.ignore_soa)
changes.sort()
if not changes:
sys.exit(0)
if opts.html:
print(format_changes_html(oldn, newn, changes, opts.ignore_ttl))
else:
print(format_changes_plain(oldn, newn, changes, opts.ignore_ttl))
sys.exit(1)
if __name__ == '__main__':
main()