lib/dnspython/examples/zonediff.py

   1 #!/usr/bin/env python
   2 #
   3 # Small library and commandline tool to do logical diffs of zonefiles
   4 # ./zonediff -h gives you help output
   5 #
   6 # Requires dnspython to do all the heavy lifting
   7 #
   8 # (c)2009 Dennis Kaarsemaker <dennis@kaarsemaker.net>
   9 #
  10 # Permission to use, copy, modify, and distribute this software and its
  11 # documentation for any purpose with or without fee is hereby granted,
  12 # provided that the above copyright notice and this permission notice
  13 # appear in all copies.
  14 #
  15 # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  16 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  17 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  18 # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  19 # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  20 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  21 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  22 """See diff_zones.__doc__ for more information"""
  23
  24 __all__ = ['diff_zones', 'format_changes_plain', 'format_changes_html']
  25
  26 try:
  27     import dns.zone
  28 except ImportError:
  29     import sys
  30     sys.stderr.write("Please install dnspython")
  31     sys.exit(1)
  32
  33 def diff_zones(zone1, zone2, ignore_ttl=False, ignore_soa=False):
  34     """diff_zones(zone1, zone2, ignore_ttl=False, ignore_soa=False) -> changes
  35     Compares two dns.zone.Zone objects and returns a list of all changes
  36     in the format (name, oldnode, newnode).
  37
  38     If ignore_ttl is true, a node will not be added to this list if the
  39     only change is its TTL.
  40
  41     If ignore_soa is true, a node will not be added to this list if the
  42     only changes is a change in a SOA Rdata set.
  43
  44     The returned nodes do include all Rdata sets, including unchanged ones.
  45     """
  46
  47     changes = []
  48     for name in zone1:
  49         name = str(name)
  50         n1 = zone1.get_node(name)
  51         n2 = zone2.get_node(name)
  52         if not n2:
  53             changes.append((str(name), n1, n2))
  54         elif _nodes_differ(n1, n2, ignore_ttl, ignore_soa):
  55             changes.append((str(name), n1, n2))
  56
  57     for name in zone2:
  58         n1 = zone1.get_node(name)
  59         if not n1:
  60             n2 = zone2.get_node(name)
  61             changes.append((str(name), n1, n2))
  62     return changes
  63
  64 def _nodes_differ(n1, n2, ignore_ttl, ignore_soa):
  65     if ignore_soa or not ignore_ttl:
  66         # Compare datasets directly
  67         for r in n1.rdatasets:
  68             if ignore_soa and r.rdtype == dns.rdatatype.SOA:
  69                 continue
  70             if r not in n2.rdatasets:
  71                 return True
  72             if not ignore_ttl:
  73                 return r.ttl != n2.find_rdataset(r.rdclass, r.rdtype).ttl
  74
  75         for r in n2.rdatasets:
  76             if ignore_soa and r.rdtype == dns.rdatatype.SOA:
  77                 continue
  78             if r not in n1.rdatasets:
  79                 return True
  80     else:
  81         return n1 != n2
  82
  83 def format_changes_plain(oldf, newf, changes, ignore_ttl=False):
  84     """format_changes(oldfile, newfile, changes, ignore_ttl=False) -> str
  85     Given 2 filenames and a list of changes from diff_zones, produce diff-like
  86     output. If ignore_ttl is True, TTL-only changes are not displayed"""
  87
  88     ret = "--- %s\n+++ %s\n" % (oldf, newf)
  89     for name, old, new in changes:
  90         ret +=  "@ %s\n" % name
  91         if not old:
  92             for r in new.rdatasets:
  93                 ret += "+ %s\n" % str(r).replace('\n','\n+ ')
  94         elif not new:
  95             for r in old.rdatasets:
  96                 ret += "- %s\n" % str(r).replace('\n','\n+ ')
  97         else:
  98             for r in old.rdatasets:
  99                 if r not in new.rdatasets or (r.ttl != new.find_rdataset(r.rdclass, r.rdtype).ttl and not ignore_ttl):
 100                     ret += "- %s\n" % str(r).replace('\n','\n+ ')
 101             for r in new.rdatasets:
 102                 if r not in old.rdatasets or (r.ttl != old.find_rdataset(r.rdclass, r.rdtype).ttl and not ignore_ttl):
 103                     ret += "+ %s\n" % str(r).replace('\n','\n+ ')
 104     return ret
 105
 106 def format_changes_html(oldf, newf, changes, ignore_ttl=False):
 107     """format_changes(oldfile, newfile, changes, ignore_ttl=False) -> str
 108     Given 2 filenames and a list of changes from diff_zones, produce nice html
 109     output. If ignore_ttl is True, TTL-only changes are not displayed"""
 110
 111     ret = '''<table class="zonediff">
 112   <thead>
 113     <tr>
 114       <th>&nbsp;</th>
 115       <th class="old">%s</th>
 116       <th class="new">%s</th>
 117     </tr>
 118   </thead>
 119   <tbody>\n''' % (oldf, newf)
 120
 121     for name, old, new in changes:
 122         ret +=  '    <tr class="rdata">\n      <td class="rdname">%s</td>\n' % name
 123         if not old:
 124             for r in new.rdatasets:
 125                 ret += '      <td class="old">&nbsp;</td>\n      <td class="new">%s</td>\n' % str(r).replace('\n','<br />')
 126         elif not new:
 127             for r in old.rdatasets:
 128                 ret += '      <td class="old">%s</td>\n      <td class="new">&nbsp;</td>\n' % str(r).replace('\n','<br />')
 129         else:
 130             ret += '      <td class="old">'
 131             for r in old.rdatasets:
 132                 if r not in new.rdatasets or (r.ttl != new.find_rdataset(r.rdclass, r.rdtype).ttl and not ignore_ttl):
 133                     ret += str(r).replace('\n','<br />')
 134             ret += '</td>\n'
 135             ret += '      <td class="new">'
 136             for r in new.rdatasets:
 137                 if r not in old.rdatasets or (r.ttl != old.find_rdataset(r.rdclass, r.rdtype).ttl and not ignore_ttl):
 138                     ret += str(r).replace('\n','<br />')
 139             ret += '</td>\n'
 140         ret += '    </tr>\n'
 141     return ret + '  </tbody>\n</table>'
 142
 143 # Make this module usable as a script too.
 144 if __name__ == '__main__':
 145     import optparse
 146     import subprocess
 147     import sys
 148     import traceback
 149
 150     usage = """%prog zonefile1 zonefile2 - Show differences between zones in a diff-like format
 151 %prog [--git|--bzr|--rcs] zonefile rev1 [rev2] - Show differences between two revisions of a zonefile
 152
 153 The differences shown will be logical differences, not textual differences.
 154 """
 155     p = optparse.OptionParser(usage=usage)
 156     p.add_option('-s', '--ignore-soa', action="store_true", default=False, dest="ignore_soa",
 157                  help="Ignore SOA-only changes to records")
 158     p.add_option('-t', '--ignore-ttl', action="store_true", default=False, dest="ignore_ttl",
 159                  help="Ignore TTL-only changes to Rdata")
 160     p.add_option('-T', '--traceback', action="store_true", default=False, dest="tracebacks",
 161                  help="Show python tracebacks when errors occur")
 162     p.add_option('-H', '--html', action="store_true", default=False, dest="html",
 163                  help="Print HTML output")
 164     p.add_option('-g', '--git', action="store_true", default=False, dest="use_git",
 165                  help="Use git revisions instead of real files")
 166     p.add_option('-b', '--bzr', action="store_true", default=False, dest="use_bzr",
 167                  help="Use bzr revisions instead of real files")
 168     p.add_option('-r', '--rcs', action="store_true", default=False, dest="use_rcs",
 169                  help="Use rcs revisions instead of real files")
 170     opts, args = p.parse_args()
 171     opts.use_vc = opts.use_git or opts.use_bzr or opts.use_rcs
 172
 173     def _open(what, err):
 174         if isinstance(what, basestring):
 175             # Open as normal file
 176             try:
 177                 return open(what, 'rb')
 178             except:
 179                 sys.stderr.write(err + "\n")
 180                 if opts.tracebacks:
 181                     traceback.print_exc()
 182         else:
 183             # Must be a list, open subprocess
 184             try:
 185                 proc = subprocess.Popen(what, stdout=subprocess.PIPE)
 186                 proc.wait()
 187                 if proc.returncode == 0:
 188                     return proc.stdout
 189                 sys.stderr.write(err + "\n")
 190             except:
 191                 sys.stderr.write(err + "\n")
 192                 if opts.tracebacks:
 193                     traceback.print_exc()
 194
 195     if not opts.use_vc and len(args) != 2:
 196         p.print_help()
 197         sys.exit(64)
 198     if opts.use_vc and len(args) not in (2,3):
 199         p.print_help()
 200         sys.exit(64)
 201
 202     # Open file desriptors
 203     if not opts.use_vc:
 204         oldn, newn = args
 205     else:
 206         if len(args) == 3:
 207             filename, oldr, newr = args
 208             oldn = "%s:%s" % (oldr, filename)
 209             newn = "%s:%s" % (newr, filename)
 210         else:
 211             filename, oldr = args
 212             newr = None
 213             oldn = "%s:%s" % (oldr, filename)
 214             newn = filename
 215
 216
 217     old, new = None, None
 218     oldz, newz = None, None
 219     if opts.use_bzr:
 220         old = _open(["bzr", "cat", "-r" + oldr, filename],
 221                     "Unable to retrieve revision %s of %s" % (oldr, filename))
 222         if newr != None:
 223             new = _open(["bzr", "cat", "-r" + newr, filename],
 224                         "Unable to retrieve revision %s of %s" % (newr, filename))
 225     elif opts.use_git:
 226         old = _open(["git", "show", oldn],
 227                     "Unable to retrieve revision %s of %s" % (oldr, filename))
 228         if newr != None:
 229             new = _open(["git", "show", newn],
 230                         "Unable to retrieve revision %s of %s" % (newr, filename))
 231     elif opts.use_rcs:
 232         old = _open(["co", "-q", "-p", "-r" + oldr, filename],
 233                     "Unable to retrieve revision %s of %s" % (oldr, filename))
 234         if newr != None:
 235             new = _open(["co", "-q", "-p", "-r" + newr, filename],
 236                         "Unable to retrieve revision %s of %s" % (newr, filename))
 237     if not opts.use_vc:
 238         old = _open(oldn, "Unable to open %s" % oldn)
 239     if not opts.use_vc or newr == None:
 240         new = _open(newn, "Unable to open %s" % newn)
 241
 242     if not old or not new:
 243         sys.exit(65)
 244
 245     # Parse the zones
 246     try:
 247         oldz = dns.zone.from_file(old, origin = '.', check_origin=False)
 248     except dns.exception.DNSException:
 249         sys.stderr.write("Incorrect zonefile: %s\n", old)
 250         if opts.tracebacks:
 251             traceback.print_exc()
 252     try:
 253         newz = dns.zone.from_file(new, origin = '.', check_origin=False)
 254     except dns.exception.DNSException:
 255         sys.stderr.write("Incorrect zonefile: %s\n" % new)
 256         if opts.tracebacks:
 257             traceback.print_exc()
 258     if not oldz or not newz:
 259         sys.exit(65)
 260
 261     changes = diff_zones(oldz, newz, opts.ignore_ttl, opts.ignore_soa)
 262     changes.sort()
 263
 264     if not changes:
 265         sys.exit(0)
 266     if opts.html:
 267         print format_changes_html(oldn, newn, changes, opts.ignore_ttl)
 268     else:
 269         print format_changes_plain(oldn, newn, changes, opts.ignore_ttl)
 270     sys.exit(1)