Posts Tagged ‘Cheers’

How to completely disable Replication in MySQL server 5.1.61 on Debian GNU / Linux

Monday, July 16th, 2012

Replication_mysql_disable

Some time ago on one of the Database MySQL servers, I've configured replication as it was required to test somethings. Eventually it turned out replication will be not used (for some reason) it was too slow and not fitting our company needs hence we needed to disable it.

It seemed logical to me that, simply removing any replication related directives from my.cnf and a restart of the SQL server will be enough to turn replication off on the Debian Linux host. Therefore I proceeded removed all replication configs from /etc/my/my.cnf and issued MySQL restart i. e.:

sql-server:~# /etc/init.d/mysql restart
....

This however didn't turned off replication,as I thought and in phpmyadminweb frontend interface, replication was still appearing to be active in the replication tab.

Something was still making the SQL server still act as an Replication Slave Host, so after a bit of pondering and trying to remember, the exact steps I took to make the replication work on the host I remembered that actually I issued:

mysql> START SLAVE;

Onwards I run:

mysql> SHOW SLAVE STATUS;
....

and found in the database the server was still running in Slave Replication mode

Hence to turn off the db host run as a Slave, I had to issue in mysql cli:

mysql> STOP SLAVE;
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> RESET SLAVE;
Query OK, 0 rows affected, 1 warning (0.01 sec)

Then after a reload of SQL server in memory, the host finally stopped working as a Slave Replication host, e.g.

sql-server:~# /etc/init.d/mysql restart
....

After the restart, to re-assure myself the SQL server is no more set to run as MySQL replication Slave host:

mysql> SHOW SLAVE STATUS;
Empty set (0.00 sec)

Cheers 😉

How to remove the meta generator Content (Joomla! – Copyright) in Joomla 1.5

Thursday, December 30th, 2010

Joomla-remove-meta-generator-content-to-hide-joomla-site-install
Do you wonder How to change <meta name="Generator" content="Joomla! – Copyright (C) 2005 – 2007 Open Source Matters. All rights reserved." /> in Joomla 1.5

If yes, Here is how I've just found to remove the:

 

in my Joomla installation.

I need to remove that as a part of making my website not to leak out that it runs on top of Joomla.

So here is how:

1. Go to your Joomla website main root directory
2. Edit /libraries/joomla/document/html/renderer/head.php
Look for line: 83 in the /libraries/joomla/document/html/renderer/head.php
There you will notice the code:

$strHtml .= $tab.'<meta name="generator" content="'.$document->getGenerator().'" />'.$lnEnd;

In order to remove the <meta name="generator" content="Joomla …." /> change the above code to something like:

$strHtml .= $tab.'<meta name="generator" content="My Custom Web site Generator name" />'.$lnEnd;

That's all now next time you refresh your website the content="Joomla! – Copyright (C) 2005 – 2009 Open Source Matters. All rights reserved." will be no more.
Cheers! 🙂

Linux: List last 10 (newest) and 10 oldest modified files in a directory with ls

Tuesday, April 8th, 2014

An useful thing on GNU / Linux sometimes is to list last or oldest modified files in directory.

Lets say you want to list last 10 modified files with ls from today / yesterday. Here is how:
 

ls -1t | head -10
my.cnf
wordperss_enabled_plugins.txt
newcerts/
mysql-hipo_pcfreakbiz.dump
NewArchive-Jan-10-15.zip
hipo_pcfreakbiz-mysqldb-any-out-1389361234.tgz
Tisho_Snimki/
wordpress/
wp-cron.php?doing_wp_cron=1.1
wp-cron.php

 

To list 10 oldest modified files on Linux:

 

ls -1t | tail -10
    my.cnf
    pcfreak_sql-15_10_05_2012
    mysql-tuning-primer*
    tuning-primer.sh*
    system-administration-services.html
    blog_backup_15_07_2012.tar.gz
    www-files/
    dump.sql
    courier-imap*
    djbdns-1.05.tar.gz


Cheers 😉

How to make GRE tunnel iptables port redirect on Linux

Saturday, August 20th, 2011

I’ve recently had to build a Linux server with some other servers behind the router with NAT.
One of the hosts behind the Linux router was running a Window GRE encrypted tunnel service. Which had to be accessed with the Internet ip address of the server.
In order < б>to make the GRE tunnel accessible, a bit more than just adding a normal POSTROUTING DNAT rule and iptables FORWARD is necessery.

As far as I’ve read online, there is quite of a confusion on the topic of how to properly configure the GRE tunnel accessibility on Linux , thus in this very quick tiny tutorial I’ll explain how I did it.

1. Load the ip_nat_pptp and ip_conntrack_pptp kernel module

linux-router:~# modprobe ip_nat_pptp
linux-router:~# modprobe ip_conntrack_pptp

These two modules are an absolutely necessery to be loaded before the remote GRE tunnel is able to be properly accessed, I’ve seen many people complaining online that they can’t make the GRE tunnel to work and I suppose in many of the cases the reason not to be succeed is omitting to load this two kernel modules.

2. Make the ip_nat_pptp and ip_nat_pptp modules to load on system boot time

linux-router:~# echo 'ip_nat_pptp' >> /etc/modules
linux-router:~# echo 'ip_conntrack_pptp' >> /etc/modules

3. Insert necessery iptables PREROUTING rules to make the GRE tunnel traffic flow

linux-router:~# /sbin/iptables -A PREROUTING -d 111.222.223.224/32 -p tcp -m tcp --dport 1723 -j DNAT --to-destination 192.168.1.3:1723
linux-router:~# /sbin/iptables -A PREROUTING -p gre -j DNAT --to-destination 192.168.1.3

In the above example rules its necessery to substitute the 111.222.223.224 ip address withe the external internet (real IP) address of the router.

Also the IP address of 192.168.1.3 is the internal IP address of the host where the GRE host tunnel is located.

Next it’s necessery to;

4. Add iptables rule to forward tcp/ip traffic to the GRE tunnel

linux-router:~# /sbin/iptables -A FORWARD -p gre -j ACCEPT

Finally it’s necessery to make the above iptable rules to be permanent by saving the current firewall with iptables-save or add them inside the script which loads the iptables firewall host rules.
Another possible way is to add them from /etc/rc.local , though this kind of way is not recommended as rules would add only after succesful bootup after all the rest of init scripts and stuff in /etc/rc.local is loaded without errors.

Afterwards access to the GRE tunnel to the local IP 192.168.1.3 using the port 1723 and host IP 111.222.223.224 is possible.
Hope this is helpful. Cheers 😉

How to change MySQL server root password

Friday, July 29th, 2011

MySQL pass dialog Debian

I had to change my mysql root password for one of the servers since during the install I mispasted the password in the MySQL password prompt I needed the pwd to be changed.

Here is how I changed it to my desired one:

linux:~# /usr/bin/mysqladmin -u root -p'OLD_PASSWORD_STRING' password NEW_PASSWORD_STRING
linux:~#

The password gets changed immediately 😉

If a new password has to be set to a passwordless mysql server, the command to be issued is:

linux:~# /usr/bin/mysqladmin -u root password PASSWORD_STRING

Changing the MySQL password is also possible with mysql cli, after connecting to the sql server, though this method is a bit more time consuming. Here is how to do it from mysql console:

linux:~# mysql -u root -p
Server version: 5.1.49-3 (Debian)

Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL v2 license

Type ‘help;’ or ‘h’ for help. Type ‘c’ to clear the current input statement.
mysql> use mysql;
mysql> update user set password=PASSWORD(“NEW_PASSWORD”) where User=’root’;mysql> flush privileges;

Of course it’s possible to do change the root pass via phpmyadmin
Cheers 😉

Solving “Cannot redeclare show_subscription_checkbox() (previously declared in .. wp-content/plugins/subscribe-to-comments/subscribe-to-comments.php”

Monday, March 21st, 2011

I’m trying to install subscribe-to-comments wordpress plugin in order to make my users to easily set a tick and receive new emails if somebody replies to their comments in my blog. Pitily downloading and trying to install the subscribe-to-comments wordpress plugin was failing after it’s activation with an error message:

PHP Fatal error: Cannot redeclare show_subscription_checkbox() (previously declared in /var/www/blog/wp-content/plugins/subscribe-to-comments/subscribe-to-comments.php:12) in /var/www/blog/wp-content/plugins/subscribe-to-comments.php on line 58"

I did my best to edit the subscribe-to-comments.php to fix up the fatal error but it was no go, so after a bunch of research I’ve found out somebody created a new version of the plugin under the name subscribe-to-comments-reloaded .

I’ve proceeded and gave a try to subscribe-to-comments-reloaded as a substitute to the old broken subscribe-to-comments .

Enabling the subscribe-to-commets-reloaded worked out of the box and the plugin now works perfectly fine and even better is enabling all the functionaity of the subscribe-to-comments
Cheers 🙂

Adding a nice advanced text editor to make wordpress wp-admin have Microsoft Word like edit functionality

Friday, September 16th, 2011

By the default wordpress does not have support for changing the exact font, therefore copying and pasting a text made in Open Office or MS Word often places in the Post or Page wp edit fonts different from the default one set for articles.
Hence some articles after being published on a wordpress blog show up with improper font and the only way to fix that is to change the font first in Open Office and then copy back to wordpress instead of simply being able to change the font from within the wordpress article.

To get around this problem, there is a nice plugin fckeditor-for-wordpress-plugin which aids wordpress with an awesome Word like edit functionalities.
, downhload location for FCKEdit for WordPress is here

Here is a screenshot of the extra nice functionality the FCKEditor for wordpress providces.

FCKEDitor for wordpress extra functionality screenshot

Installing the plugin is like installing any other wordpress plugin and comes easily to:

debian:/~# cd /var/www/blog/wp-content/plugins
debian:/plugins# wget http://downloads.wordpress.org/plugin/fckeditor-for-wordpress-plugin.3.3.1.zip
...
debian:/plugins# unzip fckeditor-for-wordpress-plugin.3.3.1.zip
...
debian:/plugins# cd fckeditor-for-wordpress-plugin/

And further enabling the plugin from:

Plugins -> Inactive -> (Dean's FCKEditor For WordPress) Enable

fckeditor for wordpress will replace the default wordpress editor TinyMCE straight after being enabled.
 I’ve done also a mirror of the current version as of time of writting of this article, one can  download the fckeditor for wordpress mirrored here 
Now really file editting inside wordpress admin panel is way easier and convenient 😉 Cheers