Posts Tagged ‘necessery’

How to install and configure djbdns from source as a Cachening Localhost Proxy resolver to increase resolving efficiency on Debian 6 Squeeze

Monday, August 1st, 2011

djbdns-logo-install-configure-djbdns-from-source-on-gnu-linux-to-accelerate-server-dns-resolving
It seems DjbDNS on Debian Squeeze has been not included as a Debian package. There is still possibility to install djbdns from an older deb package or install it from source. I however decided to install it from source as finding the old Debian package for Lenny and Etch takes time, plus I'm running an amd64 version of Debian and this might even more complicate the situation.
Installing it from source is not really a Debian way but at least it works.

In this article I assume that daemontools and ucspi-tcp are preliminary installed, if not one needs to install them with:

debian:~# apt-get install ucspi-tcp daemontools daemontools-run
...

The above two ones are required as DJBDNS is originally made to run through djb's daemontools.

Here is the exact step I took to have it installed as local caching DNS server on a Debian Squeeze server:

1. Download and untar DjbDNS

debian:~# wget -q http://cr.yp.to/djbdns/djbdns-1.05.tar.gz debian:~# tar -zxvvf djbdns-1.05.tar.gz
...

2. Add DjbDNS users to /etc/passwd

Creating the below two users is not arbitrary but it's recommendable.

echo 'dnscache:*:54321:54321:dnscache:/dev/null:/dev/null' >> /etc/passwd
echo 'dnslog:*:54322:54322:dnslog:/dev/null:/dev/null' >> /etc/passwd

3. Compile DJBDNS nameserver

First it's necessery to use the below echo command to work around a common Linux bug:

debian:~# cd djbdns-1.05
debian:/root/djbdns-1.05# echo gcc -O2 -include /usr/include/errno.h > conf-cc

Next let's make it:

debian:/root/djbdns-1.05# make

4. Install the compiled djbdns binaries

debian:/root/djbdns-1.05# make setup check
# here comes some long install related output

If no errors are produced by make setup check this means that the djbdns should have installed itself fine.

As installation is compileted it's a good idea to report about the newly installed DjbDNS server if running a mail server. This info is used by Dan Bernstein to gather statistical data about the number of installations of djbdns servers throughout the world.

5. Do some general configurations to the newly installed DJBDNS

Now let's copy the list of the IP addresses of the global DNS root servers in /etc/.

debian:/root/djbdns-1.05# cp -rpf dnsroots.global /etc/ debian:/root/djbdns-1.05# ./dnscache-conf dnscache dnslog /etc/dnscache 0.0.0.0

dnscache-conf will generate some default configuration files for djbdns in /etc/dnscache

Next allow the networks which should be able to use the just installed djbdns server as a caching server:

debian:/root/djbdns-1.05# cd /etc/dnscache/root/ip
debian:/etc/dnscache/root# touch 192.168.1
debian:/root/djbdns-1.05# touch 123.123

First command will allow all ips in range 192.168.1.* to be able to access the DNS server and the second command will allow all ips from 123.123.1-255.1-255 to be able to query the server.

Some further fine tunning can be done from the files:

/etc/dnscache/env/CACHESIZE and /etc/dnscache/env/DATALIMIT

As a last step, before it's running, we have to link the /etc/dnscache to daemontools like so:

debian:/root/djbdns-1.05# ln -sf /etc/dnscache /etc/service/dnscache

If the daemontools is not linked to be accessible via /etc/service it's also a good to link it there:

debian:~# ln -sf /etc/service /

Now the DJBDNS should be running fine, to test if it's running without errors through daemontools I used:

debian:~# ps ax|grep -i readproc
5358 pts/18 R+ 0:00 grep -i readproc
11824 ? S 0:00 readproctitle service errors: ...........

If no errors are displayed it's configured and running to also test if it's capable of resolving I used the host command:

debian:~# host www.pc-freak.net localhost
Using domain server:
Name: localhost
Address: 127.0.0.1#53
Aliases:

www.pc-freak.net has address 83.228.93.76
www.pc-freak.net mail is handled by 0 mail.www.pc-freak.net.

Now the DJBDNS is properly installed and if you test it for a while with time host somehost.com localhost , you will see how quick it is in resolving.

The advantage of running DJBDNS is it does not require almost no maintance, its rock solid and great just like all other Dan Bernstein's written software.
Enjoy 😉

12 must have Joomla extension plugins / Essential modules for new Joomla CMS install

Thursday, June 16th, 2011

Joomla bundle of must have extensions picture

These days very often I have to install, plain new Joomla based websites. I’ve realized that since there is no structured guide to follow describing the most essential plugins that every new fresh new joomla installation is required to have.
Thus I took the time and wrote this post, as it will be useful to myself in my future new joomla based websites establishment, I also believe these guide will be useful to other Joomla enthusiasts or administrators in their daily work.

Below I will describe in short the installation, configuration and oddities I’ve faced during installment of the above described bundle of plugins on a plan Joomla 1.5 install.These article will walk through 12 joomla essential plugins that I believe every fresh Joomla installation should be equipped with.
Hope this guide will be helpful to you. Now let’s start it up:

1. JoomlaXplorer – A sophisticated web file explorer for Joomla

One of the basic modules, beneficial with a new joomla CMS install is Joomla Xptplorer . This module enables the joomla admin to browse files in a web file explorer, on the server where the joomla CMS is installed. Below you see how handy the joomla web explorer provided by the plugin is:

Joomla file explorer extplorer module

Installing and using the plugin is a piece of cake. To install the plugin:

a. download Joomla file Xplorer from here or from the official plugin website.

b. Install the plugin through the admin joomla menu:

Extensions -> Install/Uninstall

c. Start using the newly installed plugin by following to menus:

Components -> eXtplorer

2. JCrawler Generate easily sitemap.xml to aim the overall Joomla website SEO optimization

JCrawler logo plugin joomla

I have previously written a very through tutorial on how to install configure and generate website sitemap with Jcrawler module, You can read my article titled: How to build website sitemap.xml in Joomla here

3. sh404SEF – Make your Joomla links and content more user friendly

sh404sef Joomla Search Engine Optimization plugin

sh404SEF is a great Joomla plugin, which will seriously improve SEO and could contribute well for a website to be better indexed with major search engines.

I have previously written an article describing thoroughfully the install and use procedures for the module.
You can read the article Making your Joomla URLS Google friendly with sh404sef plugin / Simple Joomla link SEO here

4. Akeeba Backup Joomla solution

Akeeba backup Joomla Module

Installing a joomla backup solution is very essential if you does take care about your data, it often happens that server hard disk got crashes or a RAID massives got corrupted or some kind of other unexpected disaster hits the server. In these terrible times, having a website backup will save you nerves and data recovery funds, not to mention that in many cases data recovery is impossible.

Joomla has a very easy to use software for creating full website backup called Akeeba Backup

To start using the software one must:

a. Download Akeeba Backup and install it via:

Extensions -> Install/Uninstall

After the Akeeba Backup installation is over, to create your first backup, one needs to navigate to:

Components -> Akeeba Backup -> Backup Now

Each Akeeba backup (a version of the website’s files data and sql info) will be created in an archive file with the extension .jpa
The backup files are created under joomla’s website (main) root directory in directory location administrator/components/com_akeeba/backup

The Akeeba plugin also has capabilities to recover a (.jpa) backup restore point easily.
To recover a backup with the Akeeba plugin one needs to do it once again, via the plugin joomla web interface.
5. Google Analytics (place easy tracking code) in Joomla

Google Analytics Tracking Module for Joomla

a. Download the Google Analytics Tracking Module
The module is available from Joomla Extensions on joomla.org

At the current time of writting you need to download the analytics_tracking15,zip file

b. Install the Google Analytics Tracking Module;
Login as joomla admin and navigate to;

Extensions -> Install

Place the analytics_tracking15.zip url to the Install URL: field.
Again as of time of writting you need to place https://www.pc-freak.net/files/analytics_tracking15.zip;

c. Open the Module Manager

Extensions -> Module Manager

d. Click over Google Analytics Tracking Module
On the right pane you will notice in the Module Parameters the Analytics_uacct_code field. In the uacct_code field you need to paste your UA obtained from your created google-analytics account.
This code is usually something like UA-2101595-10
Now place your code their and press the save green button located near the right top of the screen. You should see the text in blue Item Saved which would indicate your UA code is stored already in the Google Analytics Tracking Module, now press the Cancel button located again on the right top.
As a last step before the Google analytics is set-up on the Joomla you need to enable the plugin to do you need to press over the tick left sided from the text reading Google Analytics Tracking Module in the Module Manager
e. Click over the Enabled button in Module Manager;
Google Analytics Tracking Module -> Enabled

6. Itprism (Facebook, Twitter etc.) Social Network share buttons Joomla plugin

ITPShare Large Social Buttons Joomla

a. to add the itpsocialbuttons to joomla Download the Itpsocialbuttons latest module files from http://itprism.com/free-joomla-extensions/social-buttons-plugin or use my mirrored module files below:

Download mod_itpsocialbuttons .zip file
Download plg_itpsocialbuttons .zip

After having the two files necessery to be installed to make the ITPSocialButtons appear on website, installation is done like with any other installation:

Extensions -> Install/Uninstall -> Upload Package File (Choose File)

Next its necessery to configure the plugin to do so, follow to menus:

Extensions -> Module Manager -> Share

You will notice the Share dialog in the list of Module Name column in Module Manager

Here is a screenshot on how the settings options for ITpsocialbuttons will look like:

Mod ITpSocialButtons settings screen

The options which I personally changed was:

Show Title – I set this one to No as I wanted to omit the plugin title text to appear on my website.
Further on I’ve set the Enabled option to Yes to enable the plugin and choose the buttons Style option to be of a Small buttons type.
I’ve also found that the most suitable position for the Social Share buttons were to be of a right – Position .

Here is how the social network itprism share buttons looks like:

ITprism Joomla Social Share Plugin various button types

The plugin supports sharing of joomla pages to the following list of social networks:
 

  • Delicios.com
  • Digg.com
  • Facebook
  • Google Bookmarks
  • StumbleUpon
  • Technorati
  • Twitter
  • LinkedIn

The module configuration, also allows the user to configure the type of social network buttons, one wants to display on the website.

7. Joomla JCE Content Editor

This content editor is really awesome compared to the default editor TinyMCE. If you want to have an options rich content editor for Joomla, then this is the one for you 🙂
download JCE Content Editor here

After installing the JCE Joomla content editor in order to enable it as a default editor you need to go to the following location:

Site -> Global Configuration -> Default WYSIWYG Editor

There place on Editor TinyMCE and change it with Editor – JCE

Now go to edit some article, and you will see the difference in the editor 🙂

8. Add gallery Joomla capabilities with sigplus (Image Gallery Plus) and Very Simple Image Gallery

Image Gallery Plus sigplus Joomla Screenshot

Image Gallery Plus plugin (sigplus) gallery review screenshot

sigplus Image Gallery Plus is a straightforward way to add image or photo galleries to a Joomla article with a simple syntax. It takes a matter of minutes to set up a gallery but those who are looking for a powerful gallery solution will not be disappointed either: sigplus is suitable for both beginner and advanced users.

Download Sigplus Joomla Image Gallery plugin here
Using sigllus is quite easy all one has to do is use Joomla Media Manager from links:

Site -> Media Manager

Create new folder in the stories folder, let’s say New Pictures and further on use Media Manager to upload all desired pictures to be later displayed.

Being done with uploading the images you want to display, go to Article Manager :

Content -> Article Manager

From there choose your article where new uploaded pictures you want to display and type in the article:

{gallery}New Pictures{/gallery}.

Note that New Pictures is the directory just recently created as stated below, it’s important that there is no spacing between {gallery}and New Pictures, if one tries {gallery} New Pictures {/gallery} instead of {gallery}New Pictures{/gallery} an error will occur instead of the pictures being displayed in a scrolled gallery.

Sigplus Image Gallery has also a number of configuration options, which might make it look a bit more decent.
I have to say in my view the default way sigplus displays pictures is awful!

Another alternative if you don’t like Sigplus ‘s way of creating new galleries is to use Very Simple Image Gallery

Very Simple Image Gallery joomla screenshot

Here is a screenshot on a sample gallery created with Very Simple Image Gallery Joomla Plugin

You can download Very simple image gallery here

After installing the plugin. It’s use is analogous to the Sigplus . To use it likewise sigplus create new directory through Media Manager and in stories and upload your files in let’s say New Pictures1 . Later on in your article place, the code

{vsig}New Pictures1{/vsig}

Gallery will be generated automatically by the plugin. I think Simple Image Gallery is a bit more advanced and gives a better outlook to Galleries, though it’s configuration settings are much less than with SigPlus image gallery.

To add pictures comments e.g. img link alt=” and title=” tib you need to place a code within the Article manager similar to:

{vsig_c}0|Picture_1.JPG|Some sample text|Some other text{/vsig_c}
{vsig_c}0|Picture_2.JPG|Some example text|Some text{/vsig_c}
etc. ..

Note that the 0 in above example specifies the gallery number if you for instance are using a couple of galleries with Simple Image Gallery , the first one you used would be call 0 . The text specified as comments to the picture will also appear after you preview the gallery right below the picture when clicked on as a picture description in a really nice way.
9. Install Google maps plugin for Joomla

Google Maps plugin for Joomla screenshot

It’s a wise idea that every website has a location map on it’s website, for that reason Google maps is just great.
To install Google maps capability to joomla one can use a plugin called Google Maps .

You can straighly download Joomla’s Googlemap plugin from here

Afterwards use Extension Manager to install the plugin e.g. follow:

Extensions -&gr; Install/Uninstall (Choose File)

and click on Upload File & Install button.

To further enable and configure the Joomla Googlemap plugin you will have to go to the location:

Extensions -> Plugin Manager

Therein you will have to find and enable the Google Maps plugin which is to be found in the column named Plugin Manager
On my Joomla installation the plugin was located in the second page with modules, so if you don’t find the module on the listing with modules on the first page, make sure you scroll to the bottom of the page and click on Next button.

Therein in the list you will most likely notice Google Maps use the Enable button to enable it.

Next step is to configure the plugin, to do so press on the plugin name Google Maps
All configuration necessery here is to place Googlemaps API Key in the respective field (you will see it among config options).

Issuing a new Google Maps api key takes just few seconds, if you already have a gmail account just go to http://code.google.com/apis/maps/signup.html and take few seconds to issue the key.

You will get the key right on your gmail account after being issued (to repeat myself issuing takes few seconds so no worrier here).

One moreOnce having the key place it in the Googlemaps API Key field and configuring Address (which is one of the list of many options the plugin provides) you will be done with configuration.

To display a google map the location you just configured go to the Article Manager , select the article where you want the google maps location picture of your address to appear and type in the Article:

{mosmap|text='Exact street address location'|zoom='15'|zoomType='Large'|zoomNew='0'}

After you save the article a very nice Google map showing you the location’s streets will appear.
You can further conifgure a number of things related to the google map to appear, one thing you might want to play with is the zoom option which as you see in below’s code is equal to 15, e.g. zoom=’15’
Set it to another one if you want to regulate your googlemaps zoom level. For more thoroughful options take a look at the extensive plugin documentation.

10. Joomla Xmap (generating static HTML sitemap) Download Xmap from here , install it the usual plugin way.

Right after installation on the plugin succesful install screen you will notice the link component menu .
Clicking on the component menu you will be leaded to a page showing you few links Sitemap’s URL :
 

  • XML Sitemap:
  • HTML Sitemap:
  • News Sitemap:
  • Images Sitemap:

11. Add Joomla donate Paypal capabilities with Joomla PAYPAL DONATION MODULE

Paypal Donation Module Joomla Screenshot

Just recently I’ve written a a post on how to add a paypal donation capabilities to joomla, you can read my previous post here

12. Install Joomla RSForms Module (Advanced Joomla Forms Support)

Simple Joomla RsForm contact form

If you’re planning to add a complicated form support for Joomla, there are plenty of plugins, however one that was suggested by a friend of mine which is deep in Joomla world and moreover works good on my joomla installations is RSForms

Joomla – RSForms! is free to download and has great and easy interface to create new joomla forms.

At the time of writting I use these three RSForms components on new Joomla installations:

RSform Pro 1.1.0 com
Mod RsForm for Joomla 1.5
Mod Rsform list for Joomla

For latest release of RSForms! use the link http://www.rsjoomla.com/joomla-components/rsform.html

Installation is like any other module and is done through Extensions -> Install/Uninstall menu.

After installation, setting up a new form is available from the Joomla Menus:

Components -> RSform!Pro -> Manage Forms

I would not enter in details on how to edit the default RSForms or create a new RSForm. Just take some time and learn it by trying 😉

After the rsform is ready, to enable the new form, navigate to Joomla menus:

Menus -> Main Menu

Press the New button located in the buttons bar nearby the page header in the list of options in Select Menu item Type you will notice the RSForm!Pro as an option, press on it to establish the new form in the menus.

A follow up window will appear where one can set a Title: and Alias: for the new form as well as few other options.
After finalizing the settings press on Apply button to save the settings and the new form should appear in Joomla.

Probably there are many more handy plugins, which I’m missing here thus I’ll be glad if readers suggest some more helpful essential (must have plugins) for Joomla.
Feedback on this tutorial is very welcome!
Looking forward to hear for your opinions if my article was helpful to you 😉

Howto install GeoTrust RapidSSL certificate on Debian Lenny / Squeeze / Wheezy Linux

Thursday, March 25th, 2010

I faced the task of generating official Validated SSL Certificates by in mydaily duties as a System Administrator at cadiaholding.com . Though generating self-signedSSL certificate is comparatively easy task. It was a pain in the ass setting Apache version 2.2.9-10+lenny6to correctly serve pages through https:// protocol over openssl version 0.9.8g-15+lenny6.I’ll try to go through the whole process of Generating the certificate in order to help some other Debianusers out there to face less setbacks in such a simple task as installing a Trusted SSL Certificate issued(bought) by RapidSSL. Even though this article will mostly deal with SSL certificate issued by RapidSSL,it should be not a problem to apply this methodogy with Verisign or some of the other Geotrust issuedSecure Socket Layer certificates.

In generating the Validated certficate I used enom which is a domain name,ssl certificates, email and hosting company whole-saler.
Fron emon’s website after logging in and using the web interface, there are two major things required to fill inin order to issue your Trusted SSL certificate.

1. Fill in in a form a CSR file, this is usually generated on the Linux server using the openssl.
To issue the CSR file required by Enom use the following commands:

a. First we generate an DES3 RSA encrypted key which we will use next to generate the opeensl CSR file required by ENOM.
debian:~# /usr/bin/openssl genrsa -des3 -out www.domain.com.key 2048
Enter pass phrase for www.domain.com.key:

You’ll be required to fill in a pass-phrase that will be later be required to fill in before Apache servers starts or restarts,so make sure you fill something you either remember or you keep the password stored in a file.
You have to change also the www.domain.com.key in accordance with your domain name.
Now as we already have a proper generated DES3 RSA key afterwards it’s necessery to generate the CSR file with the openssl command line frontend.
So here is how:

debian:~# /usr/bin/openssl req -new -key /home/hipo/www.domain.com.key -out /home/hipo/www.domain.com.csr

Again in the above example change all the paths and file names as you wish.
It’s necessery that the end user fill in a number of questions related to the Certificate Signing Request.
Herein I’ll list what kind of prompts will emerge after executing the above command:

Enter pass phrase for /home/hipo/www.domain.com.key:
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:
State or Province Name (full name) [Some-State]:
Locality Name (eg, city) []:
Organization Name (eg, company) [Internet Widgits Pty Ltd]:
Organizational Unit Name (eg, section) []:
Common Name (eg, YOUR name) []:
Email Address []:
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

Note that you’ll hav eto fill in the pass phrase previously entered during the generation of the www.domain.com.key file.
In case if you’d like to read more thoroughly on the subject of howto create a Certificate Signing Request or (CSR) as we called it on multiple times, you can read About Certificate Signing Request (CSR) Generation Instructions – Apache SSL more in depth here

2. Hopefully following the above instructions you’ll now have a file named www.domain.csrJust open the www.domain.scr and copy paste it’s content to the ENOM website CSR * webform.

3. Further on select your Webserver type on Enom’s website:In our case we have to select Apache + ApacheSSL

4. What follows next is filling in your company contact information This is also required for proper certificate generation, you have to think twice before you fill in this data, take a note this can’t be changed later on without issuing a brand SSL new certificate.

Apart from the 3 major above requirements to fill in Enom there are some few more radio buttons to use to make some selections according to your personal preferences, however I won’t take time to dig in that and I’ll leave this to you.
After all the above is fulfilled you’ll have to submit your certificate details and choose an email address to which you will receive in a minute a RapidSSL Certificate Request Confirmation

Following a link from the email, will show you some basic information about the certificate about to be generated. That’s your final chance to cancel the issued Trusted Certificated.
If you’re absolutely sure the information about to enter the certificate is correct then you’ll have to follow a link and approve the certificate.

You’ll be informed that you’ll receive your certificate either through Certifier website (e.g. Enom’s website) or via another email.
I thought it’s more probable I receive it via email but anyways I was wrong. More thank 4 hours has passed since the certificate was issued and is available via Enom’s interface but I haven’t received nothing on my mail.
Therefore my friendly advice is to check about your brand new shiny Trusted Certificate on Emom’s website. I had mine ready in about 10 minutes after the CSR was issued.

Assuming that you’ve succesfully obtained the SSL Trusted certificate from RapidSSL what follows is setting up the certificate.
Initially I tried using documentation from RapidSSL website called Installing your SSL Certificate / Web Server Certificate / Secure Server Certificate from RapidSSL.com
I tried to configure one of my Virtualhost as shown in their example inserting in my /etc/apache/sites-available/www.domain.com file, few directives within the VirtualHost something like the shown below

SSLEngine on
# domain.com.crt cointains the Trusted SSL certificate generated and obtained by you from RapidSSL
SSLCertificateFile /etc/apache2/ssl/www.domain.com.crt
# www.domain.com.key contains the file used to generate the CSR file as described earlier in this post
SSLCertificateKeyFile /etc/apache2/ssl/www.domain.com.key

It is also possible insetad of using the SSLCertificateFile and SSLCertificateKeyFile directvies directives in Apache config to use:

 

Another alternative is to use

SSLCertificateFile /etc/ssl/certs/your-domain-name.crt
SSLCertificateKeyFile /etc/ssl/certs/your-domain-name.key
SSLCACertificateFile /etc/ssl/certs/gd_bundle.crt

The key file is the one generated earlier on the server and handed to the SSL regisrar, the files:

your-domain-name.crt and gd_bundle.crt files are provided by RapidSSL or from whatever SSL registrater the SSL was purchased.

After trying the above configuration and restarting apache with:

/etc/init.d/apache2 restart

Apache failed to start, it might be helpful to somebody out there the error I had in my apache error.log:
The error.log red the following:

[warn] RSA server certificate is a CA certificate (BasicConstraints: CA == TRUE !?)

After some 30 minutes or an hour of Googling on the error I came to the conclusion that the error is caused, becauseApache is supposed to work with .PEM files instead of the classical .CRT and .KEY files asnormally approached in most of the other Unix operating systems.

It took me a bit more of reading on the internet to find out that actually the .pem files so widely adopted in Debian simply contain both the www.domain.com.key file and the www.domain.com.crt key simply pasted one after another, this I also observed from the default Apache self-signed certificate that I believe comes with debian /etc/apache2/ssl/apache.pem .
So I copied both the content of my www.domain.com.key and www.domain.com.crt and store it in one file:
/etc/apache2/ssl/www.domain.com.pem

Also the following configuration:
SSLEngine on
SSLCertificateFile /etc/apache2/ssl/www.domain.com.pem

had to go in your
/etc/apache2/sites-enabled/www.domain.com

Last thing that’s left is to restart your Apache;

/etc/init.d/apache2 restart

Apache will prompt you for your certificate password entered by you during the www.domain.com.key generation. Type your password and with a bit of luck and hopefully with God’s help you’ll be having a Trusted Certificate on your webserver.

Last step is to check if the certificate is okay accessing your domain https://www.domain.com.

Well this is the end of the article, hope you enjoy.If you do please leave your comments, any corrections are also welcomed 🙂

Windows: VMWare Start / Stop from command line stop-vmware.bat / start-vmware.bat script

Wednesday, June 4th, 2014

vmware_start-stop-from-command-line-on-windows-os-bat-script
I'm experimenting with different Virtual Machines these days, because often running VMWare together with other Virtual Machines (like VirtualBox) might be causing crashes or VM instability – hence it is always best to have VMWare completely stopped. Unfortunately VMWare keeps running a number of respawning processes (vmnat.exe, vmnetdhcp.exe, vmware-authd.exe, vmware-usbarbitrator64.exe) which cannot be killed from Task Manager with Process KillEnd Tree option. Thus to make this services stop it is necessery run from cmd.exe (which is Run as Administrator):
 

NET STOP "VMware Workstation Server"
NET STOP "VMware USB Arbitration service"
NET STOP "VMware NAT Service"
NET STOP "VMware DHCP Service"
NET STOP "VMware Authorization Service"

If you will be doing regular START / STOP of VMWare on Windows servers it will be handy to create a little batch script stop-vmware.bat containing:
 

@ECHO OFF
NET STOP "VMware Workstation Server"
NET STOP "VMware USB Arbitration service"
NET STOP "VMware NAT Service"
NET STOP "VMware DHCP Service"
NET STOP "VMware Authorization Service"


Later whether it is necessery to start VMWare from Windows command line execute above services in reverse order (to prevent from getting warnings or errors on vmware dependent services.

NET START "VMware Authorization Service"
NET START "VMware DHCP Service"
NET START "VMware NAT Service"
NET START "VMware USB Arbitration service"
NET START "VMware Workstation Server"

To script it as a start script create file start-vmware.bat with:
 

NET START "VMware Authorization Service"
NET START "VMware DHCP Service"
NET START "VMware NAT Service"
NET START "VMware USB Arbitration service"
NET START "VMware Workstation Server"


Of course it is possible to also stop / start VMWare from GUI's Windows Services interface by righclicking on services with VMWare names and selecting "Start" / "Stop".

Configure Linux users to see only their own user processes with Hidepid – Stop users to see what others are doing

Tuesday, December 23rd, 2014

configure-Linux-users-to-see-only-ther-own-processes-with-hidepid-ps-aux-stop-system-users-to-see-what-others-are-doing
If you administer a university shared free shell Linux server, have a small community of *NIX users offering free accounts for them, or responsible for Linux software company with development servers, where programmers login and use daily to program software / websites its necessery to have tightened security rules with a major goal to keep the different user accounts processes separate one from other (hide all system and user processes from single logged in user).

Preventing users to see other users processes is essential for Linux servers which are at high risk to be hacked. At earlier times to achieve hiding all processes besides own ones from a logged in user was possible by using A kernel security module Grsecurity.
In latest currenlt Linux kernel version 3.2+ (on both Debian (unstable) / Ubuntu 14.04 / RHEL/CentOS v6.5+ above) you can hide process from other user so only root (useruser) can see all running process with (ps auxwwf) with a native kernel option hidepid. 

Configuring Hidepid

To enable hidepid option you have to remount the /proc filesystem with the Linux kernel hardening hidepid option, to make it one time setting on already running server issue:
 

 mount -o remount,rw,hidepid=2 /proc


To make the hidepid setting permanently active its necessery to modify /proc filesystem settings in /etc/fstab


 

vim /etc/fstab

proc    /proc    proc    defaults,hidepid=2     0     0
 

  • hidepid=0 – Anybody may read all world-readable /proc/PID/* files (default).
  • hidepid=1 – Means users may not access any /proc/ / directories, but only ones owned by them.Important  files like cmdline, sched*, status are now protected to read from other other users.
  • hidepid=2 – Means hidepid=1 plus all /proc/PID/ will be invisible to other users besides logged in. Using this options stops Cracker's from gathering info about running processes, indication of daemon (services) which runs with elevated privileges, other user running processes (some might contain password) passed as argument or some sensitive data. Revealing such data is frequently used to get versions of local / remote running services that can be exploited.
     

Below is output of htop of a logged in user on hidepid activated server:

:htop_screenshot_on_hideid_showing-only-own-user-credentials-gnu-linux-debian

How to disable IPv6 on Debian / Ubuntu / CentOS and RHEL Linux

Friday, December 9th, 2011

I have few servers, which have automatically enabled IPv6 protocols (IPv6 gets automatically enabled on Debian), as well as on most latest Linux distribituions nowdays.

Disabling IPv6 network protocol on Linux if not used has 2 reasons:

1. Security (It’s well known security practice to disable anything not used on a server)
Besides that IPv6 has been known for few criticil security vulnerabilities, which has historically affected the Linux kernel.
2. Performance (Sometimes disabling IPv6 could have positive impact on IPv4 especially on heavy traffic network servers).
I’ve red people claiming disabling IPv6 improves the DNS performance, however since this is not rumors and did not check it personally I cannot positively confirm this.

Disabling IPv6 on all GNU / Linuces can be achieved by changing the kernel sysctl settings net.ipv6.conf.all.disable_ipv6 by default net.ipv6.conf.all.disable_ipv6 equals 1 which means IPv6 is enabled, hence to disable IPv6 I issued:

server:~# sysctl net.ipv6.conf.all.disable_ipv6=0

To set it permanently on system boot I put the setting also in /etc/sysctl.conf :

server:~# echo 'net.ipv6.conf.all.disable = 1 >> /etc/sysctl.conf

The aforedescribed methods should be working on most Linux kernels version > 2.6.27 in that number it should work 100% on recent versions of Fedora, CentOS, Debian and Ubuntu.

To disable IPv6 protocol on Debian Lenny its necessery to blackist the ipv6 module in /etc/modprobe.d/blacklist by issuing:

echo 'blacklist ipv6' >> /etc/modprobe.d/blacklist

On Fedora / CentOS there is a another universal “Redhat” way disable IPv6.

On them disabling IPv6 is done by editting /etc/sysconfig/network and adding:

NETWORKING_IPV6=no
IPV6INIT=no

I would be happy to hear how people achieved disabling the IPv6, since on earlier and (various by distro) Linuxes the way to disable the IPv6 is probably different.
 

Alto to stop Iptables IPV6 on CentOS / Fedora and RHEL issue:

# service ip6tables stop

# service ip6tables off

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 😉

Installing Usual PHP Apache needed modules for new Debian GNU / Linux servers

Tuesday, September 18th, 2012

Almost evertime whether install a new Debian Linux server to host some websites, use the popular small and mid-sized hosting solution combination:
 

  • Apache webserver
  • PHP module to interpret the PHP programming code
  • MySQL to store the DB Backend

Installing the basis for on Debian is easy:


# apt-get install --yes apache2 apache2-mpm-prefork libapache2-mod-php \
mysql-server php5 php5-mysql mysql-client mysql-common phpmyadmin
....

This of course is in case, if necessery to run websites which are written to usephp code which is not thread safety (Use Apache child prefork technology to manage processes); For websites writen to be thread safety (not use some forking php functions like: php – exec(); fork(); etc. – I install apache2-mpm-prefork for better Webserver performance and speed.

This minimum collection of packages is good only for basic, websites and most Joomla, WordPress, Drupal or whatever custom PHP websites has to be hosted usually require much more PHP functions which are not part of this basic bundle. Hence as I said prior on almost all new Linux debian / ubuntu deb package based servers need to install following list of extra PHP deb packages:


# apt-get install --yes php-apc php-auth-ssl php-mail \
php-http php-net-smtp php-net-socket php-pear php5-cli php5-curl \
php5-gd php5-imagick php5-mapscript php5-mcrypt php5-odbc php5-sybase \
php5-xsl
...,

After installing this standard bundle of modules PHP is extended to support somenice functionalities like Image editting / convertion / resizing … various graphic editting functions as supported by infamous ImageMagick and GDlib, PEAR support (PHP Extension and Application Repository) bundle providing number of useful PHP classes.
php5-xInstalling Usual PHP Apache needed modules for new Debian GNU / Linux serverssl is usually necessery for websites which pass data in XSL format (a specific formatted XML data). php5-xsl is usually necessery for websites containing flash animationsPresentation, videos, games etc.

That is mostly it, hope this helps some sys admin like me who need configure new Debian based hosting server 🙂

Text Monitoring of connection server (traffic RX / TX) business in ASCII graphs with speedometer / Easy Monitor network traffic performance

Friday, May 4th, 2012

While reading some posts online related to MS-Windows TcpViewnetwork traffic analyzing tool. I've came across very nice tool for tracking connection speed for Linux (Speedometer). If I have to compare it, speedometer is somehow similar to nethogs and iftop bandwidth network measuring utilities .

What differentiates speedometer from iftop / nethogs / iptraf is it is more suitable for visualizing a network file or data transfers.
The graphs speedometer draws are way easier to understand, than iftop graphs.

Even complete newbies can understand it with no need for extraordinary knowledge in networking. This makes Speedometer, a top tool to visually see the amount of traffic flowing through server network interface (eth0) … (eth1) etc.

What speedometer shows is similar to the Midnight Commander's (mc) file transfer status bar, except the statistics are not only for a certain file transfer but can show overall statistics over server passing network traffic amount (though according to its manual it can be used to also track individual file transfers).

The simplicity for basic use makes speedometer nice tool to track for network congestion issues on Linux. Therefore it is a  must have outfit for every server admin. Below you see a screenshot of my terminal running speedometer on a remote server.

Speedometer ascii traffic track server network business screenshot in byobu screen like virtual terminal emulator

1. Installing speedometer on Debian / Ubuntu and Debian derivatives

For Debian and Ubuntu server administrators speedometer is already packaged as a deb so its installation is as simple as:

debian:~# apt-get --yes install speedometer
....

2. Installing speedometer from source for other Linux distributions CentOS, Fedora, SuSE etc.

Speedometer is written in python programming language, so in order to install and use on other OS Linux platforms, it is necessery to have installed (preferably) an up2date python programming language interpreter (python ver. 2.6 or higher)..
Besides that it is necessary to have installed the urwid -( console user interface library for Python) available for download via excess.org/urwid/

 

Hence to install speedometer on RedHat based Linux distributions one has to follow these steps:

a) Download & Install python urwid library

[root@centos ~]# cd /usr/local/src
[root@centos src]# wget -q http://excess.org/urwid/urwid-1.0.1.tar.gz
[root@centos src]# tar -zxvvf urwid-1.0.1.tar.gz
....
[root@centos src]# cd urwid-1.0.1
[root@centos urwid-1.0.1]# python setup.py install
running install
running build
running build_py
creating build
creating build/lib.linux-i686-2.4
creating build/lib.linux-i686-2.4/urwid
copying urwid/tests.py -> build/lib.linux-i686-2.4/urwid
copying urwid/command_map.py -> build/lib.linux-i686-2.4/urwid
copying urwid/graphics.py -> build/lib.linux-i686-2.4/urwid
copying urwid/vterm_test.py -> build/lib.linux-i686-2.4/urwid
copying urwid/curses_display.py -> build/lib.linux-i686-2.4/urwid
copying urwid/display_common.py -> build/lib.linux-i686-2.4/urwid
....

b) Download and install python-setuptools

python-setuptools is one other requirement of speedometer, happily on CentOS and Fedora the rpm package is already there and installable with yum:

[root@centos ~]# yum -y install python-setuptools
....

c) Download and install Speedometer

[root@centos urwid-1.0.1]# cd /usr/local/src/
[root@centos src]# wget -q http://excess.org/speedometer/speedometer-2.8.tar.gz
[root@centos src]# tar -zxvvf speedometer-2.8.tar.gz
.....
[root@centos src]# cd speedometer-2.8
[root@centos speedometer-2.8]# python setup.py install
Traceback (most recent call last):
File "setup.py", line 26, in ?
import speedometer
File "/usr/local/src/speedometer-2.8/speedometer.py", line 112
n = n * granularity + (granularity if r else 0)
^

While running the CentOS 5.6 installation of speedometer-2.8, I hit the
"n = n * granularity + (granularity if r else 0)
error.

After consultation with some people in #python (irc.freenode.net), I've figured out this error is caused due the outdated version of python interpreter installed by default on CentOS Linux 5.6. On CentOS 5.6 the python version is:

[root@centos ~]# python -V
Python 2.4.3

As I priorly said speedometer 2.8's minimum requirement for a python to be at v. 2.6. Happily there is quick way to update python 2.4 to python 2.6 on CentOS 5.6, as there is an RPM repository maintained by Chris Lea which contains RPM binary of python 2.6.

To update python 2.4 to python 2.6:

[root@centos speedometer-2.8]# rpm -Uvh http://yum.chrislea.com/centos/5/i386/chl-release-5-3.noarch.rpm[root@centos speedometer-2.8]# rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CHL[root@centos speedometer-2.8]# yum install python26

Now the newly installed python 2.6 is executable under the binary name python26, hence to install speedometer:

[root@centos speedometer-2.8]# python26 setup.py install
[root@centos speedometer-2.8]# chown root:root /usr/local/bin/speedometer
[root@centos speedometer-2.8]# chmod +x /usr/local/bin/speedometer

[root@centos speedometer-2.8]# python26 speedometer -i 1 -tx eth0

The -i will instruct speedometer to refresh the screen graphs once a second.

3. Using speedometer to keep an eye on send / received traffic network congestion

To observe, the amount of only sent traffic via a network interface eth0 with speedometer use:

debian:~# speedometer -tx eth0

To only keep an eye on received traffic through eth0 use:

debian:~# speedometer -rx eth0

To watch over both TX and RX (Transmitted and Received) network traffic:

debian:~# speedometer -tx eth0 -rx eth0

If you want to watch in separate windows TX and RX traffic while  running speedometer you can run in separate xterm windows speedometer -tx eth0 and speedometer -rx eth0, like in below screenshot:

Monitor Received and Transmitted server Network traffic in two separate xterm windows with speedometer ascii graphs

4. Using speedometer to test network maximum possible transfer speed between server (host A) and server (host B)

The speedometer manual suggests few examples one of which is:

How fast is this LAN?

host-a$ cat /dev/zero | nc -l -p 12345
host-b$ nc host-a 12345 > /dev/null
host-b$ speedometer -rx eth0

When I red this example in speedometer's manual, it wasn't completely clear to me what the author really meant, but a bit after when I thought over the example I got his point.

The idea behind this example is that a constant stream of zeros taken from /dev/zero will be streamed over via a pipe (|) to nc which will bind a port number 12345, anyone connecting from another host machine, lets say a server with host host-b to port 12345 on machine host-a will start receiving the /dev/zero streamed content.

Then to finally measure the streamed traffic between host-a and host-b machines a speedometer is started to visualize the received traffic on network interface eth0, thus measuring the amount of traffic flowing from host-a to host-b

I give a try to the exmpls, using for 2 test nodes my home Desktop PC, Linux running  arcane version of Ubuntu and my Debian Linux notebook.

First on the Ubuntu PC I issued
 

hipo@hip0-desktop:~$ cat /dev/zero | nc -l -p 12345
 

Note that I have previously had installed the netcat, as nc is not installed by default on Ubuntu and Debian. If you, don't have nc installed yet, install it with:

apt-get –yes install netcat

"cat /dev/zero | nc -l -p 12345" will not produce any output, but will display just a blank line.

Then on my notebook I ran the second command example, given in the speedometer manual:
 

hipo@noah:~$ nc 192.168.0.2 12345 > /dev/null

Here the 192.168.0.2 is actually the local network IP address of my Desktop PC. My Desktop PC is connected via a normal 100Mbit switch to my routing machine and receives its internet via  NAT. The second test machine (my laptop), gets its internet through a WI-FI connection received by a Wireless Router connected via a UTP cable to the same switch to which my Desktop PC is connected.

Finally to test / get my network maximum thoroughput I had to use:

hipo@noah:~$ speedometer -rx wlan0

Here, I  monitor my wlan0 interface, as this is my (laptop) wireless card interface over which I have connectivity to my local network and via which through the the WI-FI router I get connected to the internet.

Below is a snapshot captured showing approximately what is the max network thoroughput from:

Desktop PC -> to my Thinkpad R61 laptop

Using Speedometer to test network thorougput between two network server hosts screenshot Debian Squeeze Linux

As you can see in the shot approximately the maximum network thoroughput is in between:
2.55MB/s min and 2.59MB/S max, the speed is quite low for a 100 MBit local network, but this is normal as most laptop wireless adapters hardly transfer traffic in more than 10 to 20 MBits per sec.

If the same nework thoroughput test is conducted between two machines both connected to a same 100 M/bit switch, the traffic should be at least a 8 MB/sec.

There is something, else to take in consideration that probably makes the provided example network thoroughput measuring a bit inaccurate. The fact that the /dev/zero content is stremed over is slowing down the zeroes sent over network because of the  pipe ( | ) use slows down the stream.

5. Using speedometer to visualize maximum writting speed to a local hard drive on Linux

In the speedometer manual, I've noticed another interesting application of this nifty tool.

speedometer can be used to track and visualize the maximum writing speed a hard disk drive or hard drive partition can support on Linux OS:

A copy paster from the manual text is as follows:

How fast can I write data to my filesystem? (with at least 1GB free)
dd bs=1000000 count=1000 if=/dev/zero of=bigfile &
speedometer bigfile

However, when I tried copy/pasting the example in terminal, to test the maximum writing speed to an external USB hard drive, only dd command was started and speedometer failed to initialize and display graphs of the file creation speed.

I've found a little "hack" that makes the man example work by adding a 3 secs sleep like so:

debian:/media/Expansion Drive# dd bs=1000000 count=1000 if=/dev/zero of=bigfile & sleep 3; speedometer bigfile

Here is a screenshot of the bigfile created by dd and tracked "in real time" by speedometer:

How fast is writting data to local USB expandable hard disk Debian Linux speedometer screenshot

Actually the returned results from this external USB drive are, quite high, the possible reason for that is it is connected to my laptop over an USB protocol verion 3.

6. Using Speedometer to keep an eye on file download in progress

This application of speedometer is mostly useless especially on Linux where it is used as a Desktop.

However in some occasions if files are transferred over ssh or in non interactive FTP / Samba file transfers between Linux servers it can come handy.

To visualize the download and writing speed of lets say FTP transferred .AVI movie (during the actual file transfer) on the download host issue:

# speedometer Download-Folder/What-goes-around-comes-around.avi

7. Estimating approximate time for file transfer

There is another section in the speedometer manual pointing of the program use to calculate the time remaining for a file transfer.

The (man speedometer) provided example text is:

How long it will take for my 38MB transfer to finish?
speedometer favorite_episode.rm $((38*1024*1024))

At first glimpse it hard to understand (like the other manual example). A bit of reasoning and I comprehend what the man author meant by the obscure calculation:

$((38*1024*1024))

This is a formula used in which 38 has to be substituted with the exact file size amount of the transferred file. The author manual used a 38MB file so this is why he put $((38* … in the formula.

I give it a try – (just for the sake to see how it works) with a file with a size of 2500MB, in below two screenshot pictures I show my preparation to copy the file and the actual copying / "real time" transfer tracking with speedometer's status percentage completion bar.

xterm terminal copy file and estimate file copying operation speed on linux with speedometer preparation

Two xterm terminals one is copying a file the other one uses speedometer to estimate the time remaining to complete the file transfer from expansion USB hard drive to my laptop harddrive

 

How to create ssh tunnels / ssh tunneling on Linux and FreeBSD with openssh

Saturday, November 26th, 2011

ssh-tunnels-port-forwarding-windows-linux-bypassing-firewall-diagram
SSH tunneling
allows to send and receive traffic using a dedicated port. Using an ssh traffic can have many reasons one most common usage reason is to protect the traffic from a host to a remote server or to access port numbers which are by other means blocked by firewall, e.g.: (get around firewall filtering)
SSH tunneling works only with TCP traffic. The way to make ssh tunnel is with cmds:

host:/root# ssh -L localhost:deshost:destport username@remote-server.net
host:/root# ssh -R restport:desthost:localport username@remote-server.net
host:/root# ssh -X username@remote-server.net

This command will make ssh to bind a port on localhost of the host host:/root# machine to the host desthost:destport (destination host : destinationport). Important to say deshost is the host destination visible from the remote-server.net therefore if the connection is originating from remote-server.net this means desthost will be localhost.
Mutiple ssh tunnels to multiple ports using the above example commands is possible. Here is one example of ssh tunneling
Let’s say its necessery to access an FTP port (21) and an http port (80), listening on remote-server.net In that case desthost will be localhost , we can use locally the port (8080) insetad of 80, so it will be no necessery to make the ssh tunnel with root (admin privileges). After the ssh session gets opened both services will be accessible on the local ports.

host:/home/user$ ssh -L 21:localhost:21 -L 8080:localhost:80 user@remote-server.net

That’s all enjoy 😉