mirror of https://github.com/status-im/consul.git
117 lines
3.5 KiB
Markdown
117 lines
3.5 KiB
Markdown
---
|
|
layout: "docs"
|
|
page_title: "Forwarding"
|
|
sidebar_current: "docs-guides-forwarding"
|
|
---
|
|
|
|
# Forwarding DNS
|
|
|
|
By default, DNS is served from port 53 which requires root privileges.
|
|
Instead of running Consul as root, it is possible to instead run Bind
|
|
and forward queries to Consul as appropriate.
|
|
|
|
In this example, Bind and Consul are running on the same machine for
|
|
simplicity but this is not required.
|
|
|
|
### Bind Setup
|
|
|
|
First, you have to disable DNSSEC so that Consul and Bind can communicate.
|
|
This is an example configuration:
|
|
|
|
options {
|
|
listen-on port 53 { 127.0.0.1; };
|
|
listen-on-v6 port 53 { ::1; };
|
|
directory "/var/named";
|
|
dump-file "/var/named/data/cache_dump.db";
|
|
statistics-file "/var/named/data/named_stats.txt";
|
|
memstatistics-file "/var/named/data/named_mem_stats.txt";
|
|
allow-query { localhost; };
|
|
recursion yes;
|
|
|
|
dnssec-enable no;
|
|
dnssec-validation no;
|
|
|
|
/* Path to ISC DLV key */
|
|
bindkeys-file "/etc/named.iscdlv.key";
|
|
|
|
managed-keys-directory "/var/named/dynamic";
|
|
};
|
|
|
|
include "/etc/named/consul.conf";
|
|
|
|
### Zone File
|
|
|
|
Then we set up a zone for our Consul managed records in consul.conf:
|
|
|
|
zone "consul" IN {
|
|
type forward;
|
|
forward only;
|
|
forwarders { 127.0.0.1 port 8600; };
|
|
};
|
|
|
|
Here we assume Consul is running with default settings, and is serving
|
|
DNS on port 8600.
|
|
|
|
### Testing
|
|
|
|
First, perform a DNS query against Consul directly to be sure that the record exists:
|
|
|
|
[root@localhost ~]# dig @localhost -p 8600 master.redis.service.dc-1.consul. A
|
|
|
|
; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.23.rc1.32.amzn1 <<>> @localhost master.redis.service.dc-1.consul. A
|
|
; (1 server found)
|
|
;; global options: +cmd
|
|
;; Got answer:
|
|
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11536
|
|
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
|
|
|
|
;; QUESTION SECTION:
|
|
;master.redis.service.dc-1.consul. IN A
|
|
|
|
;; ANSWER SECTION:
|
|
master.redis.service.dc-1.consul. 0 IN A 172.31.3.234
|
|
|
|
;; Query time: 4 msec
|
|
;; SERVER: 127.0.0.1#53(127.0.0.1)
|
|
;; WHEN: Wed Apr 9 17:36:12 2014
|
|
;; MSG SIZE rcvd: 76
|
|
|
|
Then run the same query against your Bind instance and make sure you get a result:
|
|
|
|
[root@localhost ~]# dig @localhost -p 53 master.redis.service.dc-1.consul. A
|
|
|
|
; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.23.rc1.32.amzn1 <<>> @localhost master.redis.service.dc-1.consul. A
|
|
; (1 server found)
|
|
;; global options: +cmd
|
|
;; Got answer:
|
|
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11536
|
|
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
|
|
|
|
;; QUESTION SECTION:
|
|
;master.redis.service.dc-1.consul. IN A
|
|
|
|
;; ANSWER SECTION:
|
|
master.redis.service.dc-1.consul. 0 IN A 172.31.3.234
|
|
|
|
;; Query time: 4 msec
|
|
;; SERVER: 127.0.0.1#53(127.0.0.1)
|
|
;; WHEN: Wed Apr 9 17:36:12 2014
|
|
;; MSG SIZE rcvd: 76
|
|
|
|
### Troubleshooting
|
|
|
|
If you don't get an answer from Bind but you do get an answer from Consul then your
|
|
best bet is to turn on the query log to see what's going on:
|
|
|
|
[root@localhost ~]# rndc querylog
|
|
[root@localhost ~]# tail -f /var/log/messages
|
|
|
|
In there if you see errors like this:
|
|
|
|
error (no valid RRSIG) resolving
|
|
error (no valid DS) resolving
|
|
|
|
Then DNSSEC is not disabled properly. If you see errors about network connections
|
|
then verify that there are no firewall or routing problems between the servers
|
|
running Bind and Consul.
|