Hosting Blog

How to discard all the emails for non-existing mailboxes (Qmail server)

1. Login onto the Qmail server.

2. Create a catchall mailbox like [email protected]<domain>.com

3. Find out the domain directory with the command below-
[[email protected] ~]# ~vpopmail/bin/vdominfo <domain>.com

4. Edit the .qmail-default file as below:
[[email protected] ~]# vi /home/vpopmail/domains/<domain>.com/.qmail-default
===================================================================================
Replace the line-
| /home/vpopmail/bin/vdelivermail '' bounce-no-mailbox

With this line-
| /home/vpopmail/bin/vdelivermail '' delete
===================================================================================

5. Restart the qmail services
[[email protected] ~]# /etc/init.d/qmaild restart

How to setup a catch-all account on the Qmail server

1. Login onto the Qmail server

2. Create a catchall mailbox like [email protected]<domain>.com

3. Find out the domain directory with the command below-
[[email protected] ~]# ~vpopmail/bin/vdominfo <domain>.com

4. Edit the .qmail-default file as below:

[[email protected] ~]# vi /home/vpopmail/domains/<domain>.com/.qmail-default
===================================================================================
Replace the line-
| /home/vpopmail/bin/vdelivermail '' bounce-no-mailbox

With this line-
| /home/vpopmail/bin/vdelivermail '' /home/vpopmail/domains/<domain>.com/catchall
===================================================================================

5. Restart the qmail services
[[email protected] ~]# /etc/init.d/qmaild restart

The use of the undefined constant REQUEST_URI

$_SERVER[REQUEST_URI] is syntactically incorrect and AFAIK will not run on a default installation of PHP 5. The array index is a string so it needs to be passed strings. I know PHP 4 converted undefined constants to strings inside the square brackets but it's still not good practice.

EDIT: Well unless you define a constant called REQUEST_URI in your example script,  $_SERVER['REQUEST_URI'] is the standard method and what you should be using.

$_SERVER["REQUEST_URI"] also works and while not wrong is slightly more work for the PHP interpreter so unless you need to parse it for variables it should not be used.

Setting up the check_mk agent on Linux

 1. Verify if the server already has the check_mk agent installed, using the command below:
[[email protected] ~]# rpm -qa | grep check_mk

If this returns any matching package name, this means that the check_mk agent is already installed.

2. If no result is returned by the command above, check_mk is missing, and can be set up as per the steps below:
---------------------------------
[[email protected] ~]# cd /usr/local/src
[[email protected] ~]# wget http://mathias-kettner.de/download/check_mk-agent-1.1.10p3-1.noarch.rpm OR

[[email protected] ~]# wget http://mathias-kettner.com/download/check_mk-agent-1.2.0p3-1.noarch.rpm

[[email protected] ~]# yum --nogpgcheck -y localinstall check_mk-agent-1.1.10p2-1.noarch.rpm xinetd

[[email protected] ~]# sed -i '42 i         only_from      = 17x.x.x.x' "/etc/xinetd.d/check_mk"

[[email protected] ~]# /etc/init.d/xinetd reload
---------------------------------

3. Allow the inbound TCP port 6556 in the firewall.

Now this node can be added in the check_mk admin panel on the Nagios server.

Apache error-(28)No space left on device: Couldn't create accept lock

Scenario- Apache has stopped and is getting the error message below while starting-

[Sat Aug 16 02:22:49 2014] [emerg] (28)No space left on device: Couldn't create accept lock

Possible cause- Some semaphores might be stuck

Solution- Check semaphores on the server by using the command below
[[email protected] ~]# ipcs -s

Clear semaphores out with the command below
[[email protected] ~]# for i in `ipcs -s | awk '/httpd/ {print $2}'`; do (ipcrm -s $i); done

Start Apache now
[[email protected] ~]# /etc/init.d/httpd start

Setting Up a Django Server Using Nginx and Gunicorn

We'll setup and configure the Django server on Ubuntu. We are going to configure it with Nginx and Gunicorn for good compatibility and performance.

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