pvl.hosts: support foo:bar = ... extension fields
#!/usr/bin/env python
import pvl.args
import pvl.hosts
import pvl.dns.zone
import fnmatch
import ipaddr
import logging; log = logging.getLogger('pvl.hosts-dns')
import optparse
def process_hosts_alias (options, origin, host_domain, alias, host) :
"""
Resolve alias@domain within given zone.
"""
if host_domain :
alias = pvl.dns.join(alias, host_domain)
else :
raise ValueError("no domain given for host %s alias %s" % (host, alias, ))
if alias.endswith('.' + origin) :
# strip
alias = alias[:(len(alias) - len(origin) - 1)]
else:
raise ValueError("alias domain outside of origin: %s / %s" % (alias, origin))
return pvl.dns.zone.ZoneRecord.CNAME(alias, host)
def process_hosts_names (options, hosts, origin) :
"""
Yield ZoneRecords for hosts within the given zone.
"""
for host in hosts :
# determine label within zone
if not origin :
label = pvl.dns.join(host, host.domain)
elif host.domain == origin :
label = str(host)
elif host.domain and host.domain.endswith('.' + origin) :
fqdn = pvl.dns.join(host, host.domain)
label = fqdn[:(len(fqdn) - len(origin) - 1)]
elif host.domain :
log.debug("%s: domain %s out of zone: %s", host, host.domain, origin)
continue
else :
log.debug("%s: fqdn out of zone: %s", host, origin)
continue
if host.forward is None :
pass
elif host.forward :
forward = pvl.dns.zone.fqdn(host.forward)
log.info("%s: forward: %s", host, forward)
yield pvl.dns.zone.ZoneRecord.CNAME(label, forward)
continue
else :
log.info("%s: skip forward", host)
continue
if host.ip :
yield pvl.dns.zone.ZoneRecord.A(label, host.ip)
if host.alias4 :
yield pvl.dns.zone.ZoneRecord.A(host.ALIAS4_FMT.format(host=label), host.ip)
if host.ip6 :
yield pvl.dns.zone.ZoneRecord.AAAA(label, host.ip6)
if host.alias6 :
yield pvl.dns.zone.ZoneRecord.AAAA(label.ALIAS6_FMT.format(host=host), host.ip6)
for alias in host.alias :
yield process_hosts_alias(options, origin, host.domain, alias, label)
for alias4 in host.alias4 :
yield process_hosts_alias(options, origin, host.domain, alias4, host.ALIAS4_FMT.format(host=label))
for alias6 in host.alias6 :
yield process_hosts_alias(options, origin, host.domain, alias6, host.ALIAS6_FMT.format(host=label))
def process_hosts_forward (options, hosts, origin) :
"""
Generate DNS ZoneRecords for for hosts within the given zone origin.
"""
if options.add_origin :
yield pvl.dns.zone.ZoneDirective.build(None, 'ORIGIN', origin)
by_name = dict()
by_name_type = dict()
# list of types thare are allowed to be present for a host
MULTI_TYPES = ('A', 'AAAA')
for rr in process_hosts_names(options, hosts, origin) :
if (rr.name, rr.type) in by_name_type :
raise ValueError("%s: duplicate name/type: %s: %s" % (rr.name, rr, by_name_type[(rr.name, rr.type)]))
elif rr.type in MULTI_TYPES :
by_name_type[(rr.name, rr.type)] = rr
elif rr.name in by_name :
raise ValueError("%s: duplicate name: %s: %s" % (rr.name, rr, by_name[rr.name]))
# always check these
by_name[rr.name] = rr
# preserve ordering
yield rr
def split_ipv6_parts (prefix) :
for hextet in prefix.rstrip(':').split(':') :
for nibble in hextet.rjust(4, '0') :
yield nibble
def build_ipv6_parts (parts) :
for i in xrange(0, len(parts), 4) :
yield ''.join(parts[i:i+4])
# suffix ::
if len(parts) < 32 :
yield ''
yield ''
def parse_prefix (prefix) :
"""
Return an ipaddr.IPNetwork from given IPv4/IPv6 prefix.
>>> parse_prefix('127.0.0.0/8')
IPv4Network('127.0.0.0/8')
>>> parse_prefix('192.0.2.128/26')
IPv4Network('192.0.2.128/26')
>>> parse_prefix('192.0.2.128-26')
IPv4Network('192.0.2.128-26')
>>> parse_prefix('127.')
IPv4Network('127.0.0.0/8')
>>> parse_prefix('10')
IPv4Network('10.0.0.0/8')
>>> parse_prefix('192.168')
IPv4Network('192.168.0.0/16')
>>> parse_prefix('fe80:')
IPv6Network('fe80::/16')
>>> parse_prefix('2001:db8::')
IPv6Network('2001:db8::/32')
>>> parse_prefix('2001:db8:1:2')
IPv6Network('2001:db8:1:2::/64')
"""
if '/' in prefix :
return ipaddr.IPNetwork(prefix)
elif '-' in prefix :
return ipaddr.IPNetwork(prefix.replace('-', '/'))
elif '.' in prefix or prefix.isdigit() :
parts = prefix.rstrip('.').split('.')
prefixlen = len(parts) * 8
return ipaddr.IPv4Network('{prefix}/{prefixlen}'.format(
prefix = '.'.join(parts + ['0' for i in xrange(4 - len(parts))]),
prefixlen = prefixlen,
))
elif ':' in prefix :
parts = list(split_ipv6_parts(prefix))
prefixlen = len(parts) * 4
return ipaddr.IPv6Network('{prefix}/{prefixlen}'.format(
prefix = ':'.join(build_ipv6_parts(parts)),
prefixlen = prefixlen,
))
else :
raise ValueError("Unrecognized IP prefix string: %s" % (prefix, ))
def process_hosts_ips (options, hosts, prefix) :
"""
Yield (ip, fqnd) for hosts within given prefix.
"""
for host in hosts :
if prefix.version == 4 :
ip = host.ip
elif prefix.version == 6 :
ip = host.ip6
else :
raise ValueError("%s: unknown ip version: %s" % (prefix, prefix.version))
if not ip :
log.debug("%s: no ip%d", host, prefix.version)
continue
if ip not in prefix :
log.debug("%s: %s out of prefix: %s", host, ip, prefix)
continue
label = pvl.dns.zone.reverse_label(prefix, ip)
if host.reverse is None :
fqdn = host.fqdn()
log.info("%s %s[%s]: PTR %s", host, prefix, ip, fqdn)
yield host, ip, pvl.dns.zone.ZoneRecord.PTR(label, fqdn)
elif host.reverse :
alias = pvl.dns.zone.fqdn(host.reverse)
log.info("%s %s[%s]: CNAME %s", host, prefix, ip, alias)
yield host, ip, pvl.dns.zone.ZoneRecord.CNAME(label, alias)
else :
log.info("%s %s[%s]: omit", host, prefix, ip)
continue
def process_hosts_reverse (options, hosts, prefix) :
"""
Generate DNS ZoneRecords within the given prefix's reverse-dns zone for hosts.
"""
# collect data for records
by_ip = dict()
for host, ip, rr in process_hosts_ips(options, hosts, prefix) :
if ip in by_ip :
raise ValueError("%s: duplicate ip: %s: %s" % (host, ip, by_ip[ip]))
else :
by_ip[ip] = rr
if options.unknown_host :
# enumerate all of them
iter_ips = prefix.iterhosts()
else :
iter_ips = sorted(by_ip)
for ip in iter_ips :
if ip in by_ip :
yield by_ip[ip]
elif options.unknown_host :
label = pvl.dns.zone.reverse_label(prefix, ip)
fqdn = pvl.dns.zone.fqdn(options.unknown_host, options.hosts_domain)
log.info("%s %s[%s]: unused PTR %s", options.unknown_host, ip, prefix, fqdn)
yield pvl.dns.zone.ZoneRecord.PTR(label, fqdn)
else :
continue
def apply_zone (options, zone) :
"""
Output given ZoneRecord's
"""
for record in zone :
print unicode(record)
def main (argv) :
"""
Generate bind zonefiles from host definitions.
"""
parser = optparse.OptionParser(main.__doc__)
parser.add_option_group(pvl.args.parser(parser))
parser.add_option_group(pvl.hosts.optparser(parser))
parser.add_option('--add-origin', action='store_true',
help="Include $ORIGIN directive in zone")
parser.add_option('--forward-zone', metavar='DOMAIN',
help="Generate forward zone for domain")
parser.add_option('--reverse-zone', metavar='PREFIX',
help="Generate reverse zone for prefix")
parser.add_option('--unknown-host', metavar='NAME',
help="Generate records for unused IPs")
options, args = parser.parse_args(argv[1:])
pvl.args.apply(options)
# input
hosts = pvl.hosts.apply(options, args)
# process
if options.forward_zone :
apply_zone(options,
process_hosts_forward(options, hosts, options.forward_zone),
)
if options.reverse_zone :
apply_zone(options,
process_hosts_reverse(options, hosts, parse_prefix(options.reverse_zone)),
)
if __name__ == '__main__':
pvl.args.main(main)