PowerDNS with MySQL replication

In this article, we will set up a PowerDNS server with MySQL backend. Thanks to MySQL replication, it will no longer be necessary to configure classic zone replication through AXFR.

We configure MySQL replication as explained in this previous article.

We create the tables on the Master as indicated on the PowerDNS page:
https://doc.powerdns.com/authoritative/backends/generic-mysql.html

CREATE DATABASE pdns;
USE pdns

CREATE TABLE domains (
  id                    INT AUTO_INCREMENT,
  name                  VARCHAR(255) NOT NULL,
  master                VARCHAR(128) DEFAULT NULL,
  last_check            INT DEFAULT NULL,
  type                  VARCHAR(6) NOT NULL,
  notified_serial       INT UNSIGNED DEFAULT NULL,
  account               VARCHAR(40) CHARACTER SET 'utf8' DEFAULT NULL,
  PRIMARY KEY (id)
) Engine=InnoDB CHARACTER SET 'latin1';

CREATE UNIQUE INDEX name_index ON domains(name);

CREATE TABLE records (
  id                    BIGINT AUTO_INCREMENT,
  domain_id             INT DEFAULT NULL,
  name                  VARCHAR(255) DEFAULT NULL,
  type                  VARCHAR(10) DEFAULT NULL,
  content               VARCHAR(64000) DEFAULT NULL,
  ttl                   INT DEFAULT NULL,
  prio                  INT DEFAULT NULL,
  disabled              TINYINT(1) DEFAULT 0,
  ordername             VARCHAR(255) BINARY DEFAULT NULL,
  auth                  TINYINT(1) DEFAULT 1,
  PRIMARY KEY (id)
) Engine=InnoDB CHARACTER SET 'latin1';

CREATE INDEX nametype_index ON records(name,type);
CREATE INDEX domain_id ON records(domain_id);
CREATE INDEX ordername ON records (ordername);

CREATE TABLE supermasters (
  ip                    VARCHAR(64) NOT NULL,
  nameserver            VARCHAR(255) NOT NULL,
  account               VARCHAR(40) CHARACTER SET 'utf8' NOT NULL,
  PRIMARY KEY (ip, nameserver)
) Engine=InnoDB CHARACTER SET 'latin1';

CREATE TABLE comments (
  id                    INT AUTO_INCREMENT,
  domain_id             INT NOT NULL,
  name                  VARCHAR(255) NOT NULL,
  type                  VARCHAR(10) NOT NULL,
  modified_at           INT NOT NULL,
  account               VARCHAR(40) CHARACTER SET 'utf8' DEFAULT NULL,
  comment               TEXT CHARACTER SET 'utf8' NOT NULL,
  PRIMARY KEY (id)
) Engine=InnoDB CHARACTER SET 'latin1';

CREATE INDEX comments_name_type_idx ON comments (name, type);
CREATE INDEX comments_order_idx ON comments (domain_id, modified_at);

CREATE TABLE domainmetadata (
  id                    INT AUTO_INCREMENT,
  domain_id             INT NOT NULL,
  kind                  VARCHAR(32),
  content               TEXT,
  PRIMARY KEY (id)
) Engine=InnoDB CHARACTER SET 'latin1';

CREATE INDEX domainmetadata_idx ON domainmetadata (domain_id, kind);

CREATE TABLE cryptokeys (
  id                    INT AUTO_INCREMENT,
  domain_id             INT NOT NULL,
  flags                 INT NOT NULL,
  active                BOOL,
  published             BOOL DEFAULT 1,
  content               TEXT,
  PRIMARY KEY(id)
) Engine=InnoDB CHARACTER SET 'latin1';

CREATE INDEX domainidindex ON cryptokeys(domain_id);

CREATE TABLE tsigkeys (
  id                    INT AUTO_INCREMENT,
  name                  VARCHAR(255),
  algorithm             VARCHAR(50),
  secret                VARCHAR(255),
  PRIMARY KEY (id)
) Engine=InnoDB CHARACTER SET 'latin1';

CREATE UNIQUE INDEX namealgoindex ON tsigkeys(name, algorithm);

ALTER TABLE records ADD CONSTRAINT `records_domain_id_ibfk` FOREIGN KEY (`domain_id`) REFERENCES `domains` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;
ALTER TABLE comments ADD CONSTRAINT `comments_domain_id_ibfk` FOREIGN KEY (`domain_id`) REFERENCES `domains` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;
ALTER TABLE domainmetadata ADD CONSTRAINT `domainmetadata_domain_id_ibfk` FOREIGN KEY (`domain_id`) REFERENCES `domains` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;
ALTER TABLE cryptokeys ADD CONSTRAINT `cryptokeys_domain_id_ibfk` FOREIGN KEY (`domain_id`) REFERENCES `domains` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;

We create the database access user that PowerDNS will use:

CREATE USER pdns@'localhost' IDENTIFIED BY 'PASSWORD';
GRANT SELECT, INSERT, UPDATE, DELETE ON pdns.* to pdns@'localhost';
FLUSH PRIVILEGES;

We configure the use flags to compile PowerDNS with MySQL support:

echo "net-dns/pdns -debug -doc -geoip -ldap -libressl -lua-records -luajit -mydns mysql -postgres -protobuf -remote -sodium -sqlite -systemd -test -tinydns tools" > /etc/portage/package.use/pdns

We compile and install PowerDNS:

emerge -av net-dns/pdns

We configure PowerDNS to use MySQL as backend:
https://doc.powerdns.com/authoritative/guides/basic-database.html

We make a copy of the configuration file on both servers:

cp /etc/powerdns/pdns.conf /etc/powerdns/pdns.conf.ori

MASTER:

cat >/etc/powerdns/pdns.conf «EOL
launch=gmysql
gmysql-host=127.0.0.1
gmysql-dbname=pdns
gmysql-user=pdns
gmysql-password=PASSWORD
setgid=pdns
setuid=pdns

local-address=MASTER_IP
master=yes
default-soa-name=ns1.alfaexploit.com.
allow-axfr-ips=SLAVE_IP
also-notify=SLAVE_IP
EOL

SLAVE:

cat >/etc/powerdns/pdns.conf «EOL
launch=gmysql
gmysql-host=127.0.0.1
gmysql-dbname=pdns
gmysql-user=pdns
gmysql-password=PASSWORD
setgid=pdns
setuid=pdns

local-address=SLAVE_IP
slave=yes
default-soa-name=ns1.alfaexploit.com.
allow-notify-from=MASTER_IP/32
EOL

Start PowerDNS:

/etc/init.d/pdns start
rc-update add pdns default

Check that the service is working, create a zone on the MASTER:

pdnsutil create-zone alfaexploit.com ns1.alfaexploit.com
pdnsutil add-record alfaexploit.com ns1 A MASTER_IP
pdnsutil add-record alfaexploit.com ns2 A SLAVE_IP
pdnsutil add-record alfaexploit.com test A 1.2.3.4

Perform some queries on both the MASTER and the SLAVE:

dig @MASTER_IP test.alfaexploit.com +short

1.2.3.4

dig @SLAVE_IP test.alfaexploit.com+short

1.2.3.4

The best way to edit the zone is through edit-zone as it will present us with an editor as if it were a txt zone:

pdnsutil edit-zone alfaexploit.com

; Warning - every name in this file is ABSOLUTE!  
$ORIGIN .  
alfaexploit.com 3600    IN      SOA     ns1.alfaexploit.com hostmaster.alfaexploit.com 1 10800 3600 604800 3600  
alfaexploit.com 3600    IN      NS      ns1.alfaexploit.com  
ns1.alfaexploit.com     3600    IN      A       MASTER_IP  
ns2.alfaexploit.com     3600    IN      A       SLAVE_IP  
test.alfaexploit.com    3600    IN      A       1.2.3.4