from twisted.internet import defer
from twisted.python import failure
-import sipb_xen_database
+from invirt.config import structs as config
+import invirt.database
+import psycopg2
+import sqlalchemy
+import time
class DatabaseAuthority(common.ResolverBase):
"""An Authority that is loaded from a file."""
soa = None
- def __init__(self, domain, database=None):
+ def __init__(self, domains=None, database=None):
common.ResolverBase.__init__(self)
if database is not None:
- sipb_xen_database.connect(database)
- self.domain = domain
- self.soa = dns.Record_SOA(mname='sipb-xen-dev.mit.edu',
- rname='sipb-xen.mit.edu',
+ invirt.database.connect(database)
+ else:
+ invirt.database.connect()
+ if domains is not None:
+ self.domains = domains
+ else:
+ self.domains = config.dns.domains
+ ns = config.dns.nameservers[0]
+ self.soa = dns.Record_SOA(mname=ns.hostname,
+ rname=config.dns.contact.replace('@','.',1),
serial=1, refresh=3600, retry=900,
expire=3600000, minimum=21600, ttl=3600)
+ self.ns = dns.Record_NS(name=ns.hostname, ttl=3600)
+ record = dns.Record_A(address=ns.ip, ttl=3600)
+ self.ns1 = dns.RRHeader(ns.hostname, dns.A, dns.IN,
+ 3600, record, auth=True)
+
+
def _lookup(self, name, cls, type, timeout = None):
- if not (name.lower() == self.domain or
- name.lower().endswith('.'+self.domain)):
- #Not us
- return defer.fail(failure.Failure(dns.DomainError(name)))
+ for i in range(3):
+ try:
+ value = self._lookup_unsafe(name, cls, type, timeout = None)
+ except (psycopg2.OperationalError, sqlalchemy.exceptions.SQLError):
+ if i == 2:
+ raise
+ print "Reloading database"
+ time.sleep(0.5)
+ continue
+ else:
+ return value
+
+ def _lookup_unsafe(self, name, cls, type, timeout):
+ invirt.database.clear_cache()
+
+ ttl = 900
+ name = name.lower()
+
+ # XXX hack for the transition to two separate dev/prod clusters
+ if 'dev.xvm.mit.edu' in self.domains and name.endswith('prod.xvm.mit.edu'):
+ # import time, sys
+ # print time.localtime(), 'handling prod request', name
+ # sys.stdout.flush()
+
+ # Point the client in the right direction for prod requests.
+ authority = dns.RRHeader('prod.xvm.mit.edu', dns.NS, dns.IN, 3600,
+ dns.Record_NS(name='ns1.prod.xvm.mit.edu', ttl=3600), auth=True)
+ additional = dns.RRHeader('ns1.prod.xvm.mit.edu', dns.A, dns.IN, 3600,
+ dns.Record_A(address='18.181.0.221', ttl=3600), auth=True)
+ return defer.succeed(([], [authority], [additional]))
+
+ if name in self.domains:
+ domain = name
+ else:
+ # Look for the longest-matching domain. (This works because domain
+ # will remain bound after breaking out of the loop.)
+ best_domain = ''
+ for domain in self.domains:
+ if name.endswith('.'+domain) and len(domain) > len(best_domain):
+ best_domain = domain
+ if best_domain == '':
+ return defer.fail(failure.Failure(dns.DomainError(name)))
+ domain = best_domain
results = []
- if cls == dns.IN and type in (dns.A, dns.ALL_RECORDS):
- host = name[:-len(self.domain)-1]
- value = sipb_xen_database.Machine.get_by(name=host)
- if value is None or not value.nics:
- return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
- ip = value.nics[0].ip
- if ip is None: #Deactivated?
- return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
- ttl = 900
- record = dns.Record_A(ip, ttl)
- results.append(dns.RRHeader(name, dns.A, dns.IN,
- ttl, record, auth=True))
authority = []
- authority.append(dns.RRHeader(self.domain, dns.SOA, dns.IN, 3600,
- self.soa, auth=True))
- return defer.succeed((results, authority, []))
- #Doesn't exist
- return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
+ additional = [self.ns1]
+ authority.append(dns.RRHeader(domain, dns.NS, dns.IN,
+ 3600, self.ns, auth=True))
+
+ if cls == dns.IN:
+ host = name[:-len(domain)-1]
+ if not host: # Request for the domain itself.
+ if type in (dns.A, dns.ALL_RECORDS):
+ record = dns.Record_A(config.dns.nameservers[0].ip, ttl)
+ results.append(dns.RRHeader(name, dns.A, dns.IN,
+ ttl, record, auth=True))
+ elif type == dns.NS:
+ results.append(dns.RRHeader(domain, dns.NS, dns.IN,
+ ttl, self.ns, auth=True))
+ authority = []
+ elif type == dns.SOA:
+ results.append(dns.RRHeader(domain, dns.SOA, dns.IN,
+ ttl, self.soa, auth=True))
+ else: # Request for a subdomain.
+ if 'passup' in dir(config.dns) and host in config.dns.passup:
+ record = dns.Record_CNAME('%s.%s' % (host, config.dns.parent), ttl)
+ return defer.succeed((
+ [dns.RRHeader(name, dns.CNAME, dns.IN, ttl, record, auth=True)],
+ [], []))
+
+ value = invirt.database.Machine.get_by(name=host)
+ if value is None or not value.nics:
+ return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
+ ip = value.nics[0].ip
+ if ip is None: #Deactivated?
+ return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
+
+ if type in (dns.A, dns.ALL_RECORDS):
+ record = dns.Record_A(ip, ttl)
+ results.append(dns.RRHeader(name, dns.A, dns.IN,
+ ttl, record, auth=True))
+ elif type == dns.SOA:
+ results.append(dns.RRHeader(domain, dns.SOA, dns.IN,
+ ttl, self.soa, auth=True))
+ if len(results) == 0:
+ authority = []
+ additional = []
+ return defer.succeed((results, authority, additional))
+ else:
+ #Doesn't exist
+ return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
if '__main__' == __name__:
- resolver = DatabaseAuthority('servers.csail.mit.edu',
- 'postgres://sipb-xen@sipb-xen-dev/sipb_xen')
+ resolver = DatabaseAuthority()
verbosity = 0
f = server.DNSServerFactory(authorities=[resolver], verbose=verbosity)
projects / invirt/packages/invirt-dns.git / blobdiff