Tuesday, 10 July 2012

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, 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
and restart your MySQL server:
/etc/init.d/mysqld restart
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:
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';
(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:
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=
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
Select your language (English or Dutch):
Click to enlarge
Click on the Go to step 3 button to proceed:
Click to enlarge
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):
Click to enlarge
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 to enlarge
Click on Go to step 7:
Click to enlarge
The installation is now finished...
Click to enlarge
... 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 and log in with the username admin and the password you created during the installation:
Click to enlarge
This is how the Poweradmin web interface looks:
Click to enlarge
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:
Click to enlarge
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:
Click to enlarge
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:
Click to enlarge
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:
Click to enlarge
On the List zones page you will see that the new zone has just one record (the SOA record). Click on the edit icon...
Click to enlarge
... and then on Add record to add further records, ...
Click to enlarge
..., e.g. NS records...
Click to enlarge
... and A records (e.g. for mydomain.com (leave the Name field empty!) and www.mydomain.com)...
Click to enlarge
Click to enlarge
... and MX records:
Click to enlarge
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):
Click to enlarge
To create a PTR record that points from the IP 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:
Click to enlarge
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

;example.com.                   IN      MX

example.com.            86400   IN      MX      10 mail.example.com.

mail.example.com.       86400   IN      A

;; Query time: 44 msec
;; WHEN: Thu Jan 15 18:54:35 2009
;; MSG SIZE  rcvd: 66

[root@server1 ~]#

No comments:

Post a Comment