Installing PowerDNS (With MySQL Backend) And Poweradmin On CentOS 5.2

This article shows how you can install the PowerDNS nameserver (with MySQL backend) and the Poweradmin control panel for PowerDNS on a CentOS 5.2 system. PowerDNS is a high-performance, authoritative-only nameserver - in the setup described here it will read the DNS records from a MySQL database (similar to MyDNS), although other backends such as PostgreSQL are supported as well. Poweradmin is a web-based control panel for PowerDNS.

I do not issue any guarantee that this will work for you!

1 Preliminary Note

In this example I'm using a CentOS 5.2 host with the hostname server1.example.com and the IP address 192.168.0.100, set up according to the first 6 chapters of this tutorial: The Perfect Server - CentOS 5.2.

I will set up just one PowerDNS server in this example (a master); adding PowerDNS slave(s) can easily be achieved by using MySQL database replication from the master to the slave(s), therefore no zone transfers are needed (this again is similar to MyDNS). MySQL database replication can be set up according to this tutorial: How To Set Up Database Replication In MySQL (PowerDNS also supports native zone transfers (for scenarios where you cannot use MySQL replication) - seehttp://downloads.powerdns.com/documentation/html/replication.html).

2 Installing MySQL

To install MySQL, we do this:

yum install mysql mysql-server

Then we create the system startup links for MySQL (so that MySQL starts automatically whenever the system boots) and start the MySQL server:

chkconfig --levels 235 mysqld on

/etc/init.d/mysqld start

Now check that networking is enabled. Run

netstat -tap | grep mysql

It should show something like this (*:mysql means that MySQL is listening on all interfaces which is important for MySQL replication!):

[root@server1 ~]# netstat -tap | grep mysqltcp        0      0 *:mysql                     *:*                         LISTEN      2439/mysqld

[root@server1 ~]#

If it does not, edit /etc/my.cnf and comment out the option skip-networking:

vi /etc/my.cnf

[...] #skip-networking [...]

and restart your MySQL server:

/etc/init.d/mysqld restart

Run

mysqladmin -u root password yourrootsqlpassword

mysqladmin -h server1.example.com -u root password yourrootsqlpassword

to set a password for the user root (otherwise anybody can access your MySQL database!).

3 Installing PowerDNS

To install PowerDNS, we run

yum install pdns pdns-backend-mysql

The PowerDNS configuration is located in the /etc/pdns directory - I'll come to that in a moment.

Now we connect to MySQL:

mysql -u root -p

Type in your MySQL root password, and you should be on the MySQL shell. On the MySQL shell, we create a database for PowerDNS:

CREATE DATABASE powerdns;

Next we create a database user (powerdns) for PowerDNS:

GRANT ALL ON powerdns.* TO 'power_admin'@'localhost' IDENTIFIED BY 'power_admin_password';GRANT ALL ON powerdns.* TO 'power_admin'@'localhost.localdomain' IDENTIFIED BY 'power_admin_password';

FLUSH PRIVILEGES;

(Replace power_admin_password with a password of your choice.)

Now we create the tables needed by PowerDNS...

USE powerdns;

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 DEFAULT NULL,account VARCHAR(40) DEFAULT NULL,primary key (id)

);

CREATE UNIQUE INDEX name_index ON domains(name);

CREATE TABLE records (id INT auto_increment,domain_id INT DEFAULT NULL,name VARCHAR(255) DEFAULT NULL,type VARCHAR(6) DEFAULT NULL,content VARCHAR(255) DEFAULT NULL,ttl INT DEFAULT NULL,prio INT DEFAULT NULL,change_date INT DEFAULT NULL,primary key(id)

);

CREATE INDEX rec_name_index ON records(name);CREATE INDEX nametype_index ON records(name,type);

CREATE INDEX domain_id ON records(domain_id);

CREATE TABLE supermasters (ip VARCHAR(25) NOT NULL,nameserver VARCHAR(255) NOT NULL,account VARCHAR(40) DEFAULT NULL

);

... and finally leave the MySQL shell:

quit;

Now we must configure PowerDNS so that it uses the MySQL backend:

vi /etc/pdns/pdns.conf

Add the following lines to pdns.conf:

[...] ################################# # launch Which backends to launch and order to query them in # # launch= launch=gmysql gmysql-host=127.0.0.1 gmysql-user=power_admin gmysql-password=power_admin_password gmysql-dbname=powerdns [...]

Then create the system startup links for PowerDNS and start it:

chkconfig --levels 235 pdns on

/etc/init.d/pdns start

That's it, PowerDNS is now ready to be used. To learn more about it, please refer to its documentation:http://downloads.powerdns.com/documentation/html/index.html

4 Installing Poweradmin

Now let's install Poweradmin, a web-based control panel for PowerDNS. Poweradmin is written in PHP, so we must install a web server (I'm using Apache2 in this example) and PHP:

yum install httpd php php-devel php-gd php-imap php-ldap php-mysql php-odbc php-pear php-xml php-xmlrpc php-mbstring php-mcrypt php-mhash gettext

Create the system startup links for Apache2 and start it:

chkconfig --levels 235 httpd on

/etc/init.d/httpd start

Poweradmin also requires the following two PEAR packages:

yum install php-pear-DB php-pear-MDB2-Driver-mysql

Now all prerequisites for Poweradmin are installed, and we can begin with the Poweradmin installation (I will install it in a subdirectory of /var/www/html - /var/www/html is the document root of Apache's default web site on CentOS; if you've created a vhost with a different document root, please adjust the paths).

Go to https://www.poweradmin.org/trac/wiki/GettingPoweradmin and download the latest Poweradmin package, e.g. as follows:

cd /tmp

wget https://www.poweradmin.org/download/poweradmin-2.1.2.tgz

Then install it to the /var/www/html/poweradmin directory as follows:

tar xvfz poweradmin-2.1.2.tgzmv poweradmin-2.1.2 /var/www/html/poweradmintouch /var/www/html/poweradmin/inc/config.inc.php

chown -R apache:apache /var/www/html/poweradmin/

Now open a browser and launch the web-based Poweradmin installer (http://server1.example.com/poweradmin/installor http://192.168.0.100/poweradmin/install).

Select your language (English or Dutch):

Click on the Go to step 3 button to proceed:

Now fill in your database details. It is important that you fill in the details for the MySQL root user, not the powerdns MySQL user we created earlier! Also provide a password for the admin user for the Poweradmin web interface (that's the password that the user admin will use to log in to Poweradmin later on):

On the next page, fill in the details for the power_admin MySQL user that we created in chapter 3. Also fill in the two default nameservers that will be used in your zones unless you provide different nameservers when you create a zone (typically these are the names of the current system and of the slave server (for which you can set up MySQL replication, see my preliminary notes in chapter 1)):

On the next screen the installer asks you to execute a MySQL query. We don't have to do that because we've done something similar in chapter 3 already (the two GRANT statements) so we are set. Click on Go to step 6:

Click on Go to step 7:

The installation is now finished...

... but for security reasons we must delete the install directory:

rm -fr /var/www/html/poweradmin/install/

Now you can go to http://server1.example.com/poweradmin or http://192.168.0.100/poweradmin and log in with the username admin and the password you created during the installation:

This is how the Poweradmin web interface looks:

To create a zone, go to Add master zone and fill in the domain name (e.g. example.com). You can already fill in the IP addresses for the www A record ("webserver") and the MX record ("mailserver") for that zone. If you leave the Create zone without applying records-template checkbox unchecked, Poweradmin will automatically create some NS, A (e.g. www) and MX records for that zone:

Go to List zones afterwards. You should now see the new zone there, and it already has eight records. Click on the edit icon to see these eight records:

These are the records that are created automatically unless you check the Create zone without applying records-template checkbox when you create a zone. You can now edit them or add and delete records:

Of course, you can as well create all records one-by-one manually - just leave the IP address fields empty and check theCreate zone without applying records-template checkbox on the Add master zone page:

On the List zones page you will see that the new zone has just one record (the SOA record). Click on the edit icon...

... and then on Add record to add further records, ...

..., e.g. NS records...

... and A records (e.g. for mydomain.com (leave the Name field empty!) and www.mydomain.com)...

... and MX records:

To create PTR records, go to the Add master zone page and create a zone called in-addr.arpa (leave the IP address fields empty and check the Create zone without applying records-template checkbox):

To create a PTR record that points from the IP 1.2.3.4 to server1.example.com, create a record under List zones and fill in4.3.2.1 in the Name field (that's the IP in reverse order) and server1.example.com in the Content field:

After you've created your records, you can check them with the dig command (see

man dig

for more details), e.g. as follows:

dig @localhost mx example.com

[root@server1 ~]# dig @localhost mx example.com

; <<>> DiG 9.3.4-P1 <<>> @localhost mx example.com
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46586
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;example.com.                   IN      MX

;; ANSWER SECTION:
example.com.            86400   IN      MX      10 mail.example.com.

;; ADDITIONAL SECTION:
mail.example.com.       86400   IN      A       1.2.3.4

;; Query time: 44 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Thu Jan 15 18:54:35 2009
;; MSG SIZE  rcvd: 66

[root@server1 ~]#