lemur/lemur/plugins/lemur_acme/dyn.py

286 lines
9.2 KiB
Python

import time
import dns
import dns.exception
import dns.name
import dns.query
import dns.resolver
from dyn.tm.errors import (
DynectCreateError,
DynectDeleteError,
DynectGetError,
DynectUpdateError,
)
from dyn.tm.session import DynectSession
from dyn.tm.zones import Node, Zone, get_all_zones
from flask import current_app
from lemur.extensions import metrics, sentry
def get_dynect_session():
try:
dynect_session = DynectSession(
current_app.config.get("ACME_DYN_CUSTOMER_NAME", ""),
current_app.config.get("ACME_DYN_USERNAME", ""),
current_app.config.get("ACME_DYN_PASSWORD", ""),
)
except Exception as e:
sentry.captureException()
metrics.send("get_dynect_session_fail", "counter", 1)
current_app.logger.debug("Unable to establish connection to Dyn", exc_info=True)
raise
return dynect_session
def _has_dns_propagated(fqdn, token):
txt_records = []
try:
dns_resolver = dns.resolver.Resolver()
dns_resolver.nameservers = [get_authoritative_nameserver(fqdn)]
dns_response = dns_resolver.query(fqdn, "TXT")
for rdata in dns_response:
for txt_record in rdata.strings:
txt_records.append(txt_record.decode("utf-8"))
except dns.exception.DNSException:
metrics.send("has_dns_propagated_fail", "counter", 1, metric_tags={"dns": fqdn})
return False
for txt_record in txt_records:
if txt_record == token:
metrics.send("has_dns_propagated_success", "counter", 1, metric_tags={"dns": fqdn})
return True
return False
def wait_for_dns_change(change_id, account_number=None):
fqdn, token = change_id
number_of_attempts = 20
for attempts in range(0, number_of_attempts):
status = _has_dns_propagated(fqdn, token)
current_app.logger.debug("Record status for fqdn: {}: {}".format(fqdn, status))
if status:
metrics.send("wait_for_dns_change_success", "counter", 1, metric_tags={"dns": fqdn})
break
time.sleep(10)
if not status:
# TODO: Delete associated DNS text record here
metrics.send("wait_for_dns_change_fail", "counter", 1, metric_tags={"dns": fqdn})
sentry.captureException(extra={"fqdn": str(fqdn), "txt_record": str(token)})
metrics.send(
"wait_for_dns_change_error",
"counter",
1,
metric_tags={"fqdn": fqdn, "txt_record": token},
)
return
def get_zone_name(domain):
zones = get_all_zones()
zone_name = ""
for z in zones:
if domain.endswith(z.name):
# Find the most specific zone possible for the domain
# Ex: If fqdn is a.b.c.com, there is a zone for c.com,
# and a zone for b.c.com, we want to use b.c.com.
if z.name.count(".") > zone_name.count("."):
zone_name = z.name
if not zone_name:
metrics.send("dyn_no_zone_name", "counter", 1)
raise Exception("No Dyn zone found for domain: {}".format(domain))
return zone_name
def get_zones(account_number):
get_dynect_session()
zones = get_all_zones()
zone_list = []
for zone in zones:
zone_list.append(zone.name)
return zone_list
def create_txt_record(domain, token, account_number):
get_dynect_session()
zone_name = get_zone_name(domain)
zone_parts = len(zone_name.split("."))
node_name = ".".join(domain.split(".")[:-zone_parts])
fqdn = "{0}.{1}".format(node_name, zone_name)
zone = Zone(zone_name)
try:
zone.add_record(
node_name, record_type="TXT", txtdata='"{}"'.format(token), ttl=5
)
zone.publish()
current_app.logger.debug(
"TXT record created: {0}, token: {1}".format(fqdn, token)
)
except (DynectCreateError, DynectUpdateError) as e:
if "Cannot duplicate existing record data" in e.message:
current_app.logger.debug(
"Unable to add record. Domain: {}. Token: {}. "
"Record already exists: {}".format(domain, token, e),
exc_info=True,
)
else:
metrics.send("create_txt_record_error", "counter", 1)
sentry.captureException()
raise
change_id = (fqdn, token)
return change_id
def delete_txt_record(change_id, account_number, domain, token):
get_dynect_session()
if not domain:
current_app.logger.debug("delete_txt_record: No domain passed")
return
zone_name = get_zone_name(domain)
zone_parts = len(zone_name.split("."))
node_name = ".".join(domain.split(".")[:-zone_parts])
fqdn = "{0}.{1}".format(node_name, zone_name)
zone = Zone(zone_name)
node = Node(zone_name, fqdn)
try:
all_txt_records = node.get_all_records_by_type("TXT")
except DynectGetError:
metrics.send("delete_txt_record_geterror", "counter", 1)
# No Text Records remain or host is not in the zone anymore because all records have been deleted.
return
for txt_record in all_txt_records:
if txt_record.txtdata == ("{}".format(token)):
current_app.logger.debug("Deleting TXT record name: {0}".format(fqdn))
try:
txt_record.delete()
except DynectDeleteError:
sentry.captureException(
extra={
"fqdn": str(fqdn),
"zone_name": str(zone_name),
"node_name": str(node_name),
"txt_record": str(txt_record.txtdata),
}
)
metrics.send(
"delete_txt_record_deleteerror",
"counter",
1,
metric_tags={"fqdn": fqdn, "txt_record": txt_record.txtdata},
)
try:
zone.publish()
except DynectUpdateError:
sentry.captureException(
extra={
"fqdn": str(fqdn),
"zone_name": str(zone_name),
"node_name": str(node_name),
"txt_record": str(txt_record.txtdata),
}
)
metrics.send(
"delete_txt_record_publish_error",
"counter",
1,
metric_tags={"fqdn": str(fqdn), "txt_record": str(txt_record.txtdata)},
)
def delete_acme_txt_records(domain):
get_dynect_session()
if not domain:
current_app.logger.debug("delete_acme_txt_records: No domain passed")
return
acme_challenge_string = "_acme-challenge"
if not domain.startswith(acme_challenge_string):
current_app.logger.debug(
"delete_acme_txt_records: Domain {} doesn't start with string {}. "
"Cowardly refusing to delete TXT records".format(
domain, acme_challenge_string
)
)
return
zone_name = get_zone_name(domain)
zone_parts = len(zone_name.split("."))
node_name = ".".join(domain.split(".")[:-zone_parts])
fqdn = "{0}.{1}".format(node_name, zone_name)
zone = Zone(zone_name)
node = Node(zone_name, fqdn)
all_txt_records = node.get_all_records_by_type("TXT")
for txt_record in all_txt_records:
current_app.logger.debug("Deleting TXT record name: {0}".format(fqdn))
try:
txt_record.delete()
except DynectDeleteError:
sentry.captureException(
extra={
"fqdn": str(fqdn),
"zone_name": str(zone_name),
"node_name": str(node_name),
"txt_record": str(txt_record.txtdata),
}
)
metrics.send(
"delete_txt_record_deleteerror",
"counter",
1,
metric_tags={"fqdn": fqdn, "txt_record": txt_record.txtdata},
)
zone.publish()
def get_authoritative_nameserver(domain):
if current_app.config.get("ACME_DYN_GET_AUTHORATATIVE_NAMESERVER"):
n = dns.name.from_text(domain)
depth = 2
default = dns.resolver.get_default_resolver()
nameserver = default.nameservers[0]
last = False
while not last:
s = n.split(depth)
last = s[0].to_unicode() == u"@"
sub = s[1]
query = dns.message.make_query(sub, dns.rdatatype.NS)
response = dns.query.udp(query, nameserver)
rcode = response.rcode()
if rcode != dns.rcode.NOERROR:
metrics.send("get_authoritative_nameserver_error", "counter", 1)
if rcode == dns.rcode.NXDOMAIN:
raise Exception("%s does not exist." % sub)
else:
raise Exception("Error %s" % dns.rcode.to_text(rcode))
if len(response.authority) > 0:
rrset = response.authority[0]
else:
rrset = response.answer[0]
rr = rrset[0]
if rr.rdtype != dns.rdatatype.SOA:
authority = rr.target
nameserver = default.query(authority).rrset[0].to_text()
depth += 1
return nameserver
else:
return "8.8.8.8"