Linux install and configure pound reverse proxy for Apache http / https web server

December 11, 2007December 13, 2007in Apache, CentOS, Debian / Ubuntu, Linux, Networking, Ubuntu Linux last updated December 13, 2007

Q. How do I install and configure pound reverse proxy for Apache web sever under Debian Linux?

A. Pound is a reverse-proxy load balancing server. It accepts requests from HTTP / HTTPS clients and distributes them to one or more Web servers. The HTTPS requests are decrypted and passed to the back-ends as plain HTTP. It will act as:
a) Server load balancer
b) Reverse proxy server
c) Apache reverse proxy etc
d) It can detects when a backend server fails or recovers, and bases its load balancing decisions on this information: if a backend server fails, it will not receive requests until it recovers
e) It can decrypts https requests to http ones
f) Rejects incorrect requests
h) It can be used in a chroot environment (security feature)

If more than one back-end server is defined, Pound chooses one of them randomly, based on defined priorities. By default, Pound keeps track of associations between clients and back-end servers (sessions).

Install Pound Software

Type the following command to install pound:
$ sudo apt-get install pound
If you are using RHEL / CentOS, grab pound rpm here and type the command:
# rpm -ivh pound*
If you are using FreeBSD, enter:
# cd /usr/ports/www/pound/ && make install clean

How it works?

Let us assume your public IP address 202.54.1.5.
Pound will run on 202.54.1.5 port 80
It will forward all incoming http requests to internal host 192.168.1.5 and 192.168.1.10 port 80 or 443
Pound keeps track of associations between clients and back-end servers

Pound configuration file

Under Debian / Ubuntu default file located at /etc/pound/pound.cfg
Under FreeBSD it is located at /usr/local/etc/pound.cfg (you need to create this file)
Under RHEL / CentOS you need to create file at /etc/pound.cfg

Sample configuration: HTTP Proxy

Forward all incoming request at 202.54.1.5 port 80 request to 192.168.1.5 Apache server running at 8080 port:
Open /etc/pound/pound.cfg file:
# vi /etc/pound/pound.cfg
To translate HTTP requests to a local internal HTTP server, enter (make sure 192.168.1.5 Apache running listing on port 8080):

ListenHTTP
         Address 202.54.1.5
         Port    80
         Service
                  BackEnd
                       Address 192.168.1.5
                       Port    8080
                  End
          End
End

Save and close the file. Restart pound:
# /etc/init.d/pound restart

Following example will distribute the all HTTP/HTTPS requests to two Web servers:

ListenHTTP
          Address 202.54.1.5
          Port    80
End

ListenHTTPS
         Address 202.54.1.5
         Port    443
         Cert    "/etc/ssl/local.server.pem"
End
Service
                  BackEnd
                      Address 192.168.1.5
                      Port    80
                  End
                  BackEnd
                      Address 192.168.1.6
                      Port    80
                  End
End

For testing purpose you may generate self signed ssl certificate (/etc/ssl/local.server.pem), by entering the following command:
# cd /etc/ssl && openssl req -x509 -newkey rsa:1024 -keyout local.server.pem -out local.server.pem -days 365 -nodes

Pound log file

By default pound log message using syslog:
# tail -f /var/log/messages # grep pound /var/log/messages

Sample complete configuration file

## Minimal sample pound.cfg
######################################################################
## global options:
User		"www-data"
Group		"www-data"
#RootJail	"/chroot/pound"
## Logging: (goes to syslog by default)
##	0	no logging
##	1	normal
##	2	extended
##	3	Apache-style (common log format)
LogLevel	1
## check backend every X secs:
Alive		30
## use hardware-accelleration card supported by openssl(1):
#SSLEngine	""

######################################################################
## listen, redirect and ... to:
# Here is a more complex example: assume your static images (GIF/JPEG) are to be served from  a  single  back-end  192.168.0.10.  In
#       addition,  192.168.0.11  is  to  do  the  hosting for www.myserver.com with URL-based sessions, and 192.168.0.20 (a 1GHz PIII) and
#       192.168.0.21 (800Mhz Duron) are for all other requests (cookie-based sessions).  The logging will be done by the back-end servers.
#       The configuration file may look like this:
              # Main listening ports
              ListenHTTP
                  Address 202.54.1.10
                  Port    80
                  Client  10
              End
              ListenHTTPS
                  Address 202.54.1.10
                  Port    443
                  Cert    "/etc/pound/pound.pem"
                  Client  20
              End

              # Image server
              Service
                  URL ".*.(jpg|gif)"
                  BackEnd
                      Address 192.168.1.10
                      Port    80
                  End
              End
             # Virtual host www.myserver.com
              Service
                  URL         ".*sessid=.*"
                  HeadRequire "Host:.*www.nixcraft.com.*"
                  BackEnd
                      Address 192.168.1.11
                      Port    80
                  End
                  Session
                      Type    PARM
                      ID      "sessid"
                      TTL     120
                  End
              End

              # Everybody else
              Service
                  BackEnd
                      Address 192.168.1.20
                      Port    80
                      Priority 5
                  End
                  BackEnd
                      Address 192.168.1.21
                      Port    80
                      Priority 4
                  End
                  Session
                      Type    COOKIE
                      ID      "userid"
                      TTL     180
                  End
              End

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

23 comment

`ariel says:
December 11, 2007 at 1:38 pm
Nice !!! a few weeks ago i was googling for something like this for hours !!!
Reply Report comment
nixCraft says:
December 11, 2007 at 1:45 pm
Pound is simple and very nice. Many large site such as wordpress.com uses pound.
Reply Report comment
Calomel says:
December 12, 2007 at 4:35 pm
I would highly suggest pound or lighttpd as a reverse proxy. As of version 2.4e, Pound is extremely fast and stable. Lighttpd did have some problems in the past and most of those have been fixed. Memeory managment has been greatly improved. I have to agree about the documentation, but there are examples like the following to help everyone out:
Pound Reverse Proxy “how “to”
http://calomel.org/pound.html
Light webserver “how to”
http://calomel.org/lighttpd.html
Reply Report comment
nixCraft says:
December 12, 2007 at 5:06 pm
Calomel,
Thanks for sharing your links. You got some pretty good stuff :)
Reply Report comment
Babar says:
December 14, 2007 at 3:48 pm
I am having the same thing using squid as reverse proxy. Seems to be doing pretty well for the time being.
Reply Report comment
Erik says:
December 15, 2007 at 2:48 am
To bad it doesn’t do caching. Also crossraods is a good LB as-well.
Reply Report comment
ajay says:
December 31, 2007 at 7:37 am
i have a linux system white box loaded. tell me how to configure its lan card for internet connection while server proxy address= 192.168.10.1
port : 6080
Reply Report comment
McKeder says:
April 16, 2008 at 2:59 pm
I am extremely happy to have a tutorial like this. Until Recently, I had no idea what a Reverse Proxy was and this really helped me to understand it.
Thanks! and keep up all the great work!
Reply Report comment

HI Folks,

I have a deadline and the time is ticking. i am setting up pound as a reverser proxy for a site that runs on port 8080. I m trying to run pound on 80 and direct all the traffic to port 8080. i have pound up and running and the redirect happens fine just that when it redirects it gives me this error
“The service is not available. Please try again later”
i believe i need to add some directive under the pound.cfg fine but not sure what. this is what i have for pound.cfg

User        "pound"
Group       "pound"
LogFacility daemon
LogLevel    4
Alive       30
Client      10
TimeOut     10
Grace       10

ListenHTTP
   Address    0.0.0.0
   CheckURL   "(^\/|\.html|\.css|\.jpg|favicon\.ico|robots\.txt|\.png)$"
   HeadRemove "X-Forwarded-For"
   MaxRequest 1024
   Port       80
   xHTTP      0

  # Err414 "/var/www/htdocs/error/generic_error_page"
  # Err500 "/var/www/htdocs/error/generic_error_page"
  # Err501 "/var/www/htdocs/error/generic_error_page"
  # Err503 "/var/www/htdocs/error/generic_error_page"

Service
                  URL         ".*sessid=.*"
                  HeadRequire "Host:.*web249.solutionset.com.*"
      BackEnd
         Address  127.0.0.1
         Port     8080
      End
      Emergency
       Address    127.0.0.1
       Port       8888
      End
   End
End

i am very new to pound so any help would be really appreciated. Thank you

Reply Report comment

Guys,

First I must say thank you for making reverse proxy so easy to configure and making techs life easy. I am running Pound 2.4.3 on RHEL5 server. I have three websites each running on separate webserver in internal network. I would like to reverse proxy them via one Pound server in DMZ. All three websites require secure connections for client and I like to install the certificates on the pound server for them. I have assigned three IPs on the pound server, one for each website. But these sites are not working. Below is my configuration.

   ListenHTTP
         Address 202.168.1.1
         Port    80
         Service
         Redirect "https://www.abc.com"
          End
End

ListenHTTPS
         Address 202.168.1.1
         Port    443
         Cert    "/usr/local/openssl/local.server.pem"
End
                  Service
                  BackEnd
                      Address 172.17.1.1
                      Port    80
                  End

End


ListenHTTP
         Address 202.168.2.2
         Port    80
         Service
         Redirect "https://www.def.com"
           End
End

ListenHTTPS
         Address 202.168.2.2
         Port    443
         Cert    "/usr/local/openssl/local1.server.pem"
End
                  Service
                  BackEnd
                      Address 172.17.2.2
                      Port    80
                  End


End


ListenHTTP
         Address 202.168.3.3
         Port    80
         Service
         Redirect "https://www.ghi.com"
           End
End

ListenHTTPS
         Address 202.168.3.3
         Port    443
         Cert    "/usr/local/openssl/local2.server.pem"
End
                  Service
                  BackEnd
                      Address 172.17.3.3
                      Port    80
                  End

End

I am redirecting HTTP requests to HTTPS as I would only like to serve clients on secure channel. This works fine if I run each website on a separate pound server but I like to have them on one reverse proxy server. I will really appreciate if you can provide me any help in this regard. If it is not possible with this configuration is there any way to achieve this on a single pound server.

Thanks,
Farhan