Rails application deployment with heroku

Install git
Generate RSA public and Private keys in your system
Required Gems
Heroko
Taps - By default heroku uses postgreSQL as the database, so use this gem to convert your database from mysql to postgresql.

First create an account in heroku.com website.
Open terminal and CD to the application you want to deploy
#git init
#git add .
#git commit -m 'First submit'
Till now one empty git repository (.git) created in your local application folder and save the changes in the local repository.

#heroku create appname
It will ask you the email and password which you have already signup in heroku.com and create the appname in heroku as subdomain. i.e appname.heroku.com

#git push heroku master
This command will transfer all your files from local repo to the heroku application.

Process for Database Push and Pull
#heroku rake db:migrate
This will migrate all your local db to heroku, Make sure to maintain migrations clearly
#heroku rake db:push

Sometimes you may face many problems in db migrations, so take care of db migrations. If you face problems, just us heroku db:push without heroku rake db:migrate.

#Other commands
#heroku db:pull
to pull the db from heroku
#heroku db:open
to c all heroku commands


Repeate the above process when you change any modification to the files.

MYD files in mysql/data/database folder are not shown in database

Hi,
When you copy the database from c:/appserv/mysql/data/ folder instead export from phpmyadmin, and paste the copied database in some other system in c:/appserv/mysql/data/ folder, some times it might not work properly, it creates the database in the phpmyamdin but tables are not shown in that db. Solution for this problem is make sure the folder in c:/appserv/mysql/data/ is writeble and executable, Provide full permissions to this folder to the user who uses the phpmyadmin.

Linux SSH Error - Remote host identification changed

Hi all,
when I try to connect to my remote host through ssh, it throws an error called Remote host identification is changed, below is the process for how can we get rid of this message.

The possible reasons for getting this error are:
If os and openssh in your system is reinstalled, or os or openssh is reinstalled in remote system.
You have assigned the IP address of one system to another system and trying to ssh.
You system is dual boot with different ssh keys in both flavors of linux.
You are using an IP for load balancing and trying to ssh to the same IP.
You generated new ssh keys for your system.

When you tries to login to a remote system through ssh, then the destination hosts provides it’s keys and asked whether these keys are trusted and then those keys are added to your trusted database(known_hosts file). Whenever you tries to login again to the same system, the received keys are checked against the keys available in your file and if both matches then the next step occurs, which is authentication. But if due to any of the above given reason, the keys doesn’t match, then you will get this error and won’t be able to login.

The solution for this problem is
Just remove the old key for remote host from your system's known_hosts file, So when you try to connect through ssh it will again ask you to store the key in the known_hosts file.
OR
Completely Remove keys from known_hosts file
To remove the old keys from the known_hosts file, we can use -R option. This option will remove all the obsolete/old keys from your file. This can be used like this:
# ssh-keygen -R
# ssh-keygen -R

The path for known_hosts file is
In linux
home/venkat(username)/.ssh folder
In windows
c:/documentes and settings/venkat

Install and Remove RPM packages in linux

Install local rpm package
# rpm -ivh foo-2.0-4.i386.rpm
Install from remote host
# rpm -i ftp://ftp.redhat.com/pub/redhat/RPMS/foo-1.0-1.i386.rpm
# rpm -i http://oss.oracle.com/projects/firewire/dist/files/kernel-2.4.20-18.10.1.i686.rpm

Remove package
# rpm -e foo
To uninstall a RPM package. Note that we used the package name foo, not the name of the original package file foo-2.0-4.i386.rpm above

To upgrade
# rpm -Uvh foo-1.0-2.i386.rpm
# rpm -Uvh ftp://ftp.redhat.com/pub/redhat/RPMS/foo-1.0-1.i386.rpm
# rpm -Uvh http://oss.oracle.com/projects/firewire/dist/files/kernel-2.4.20-18.10.1.i686.rpm

Wordpress usefull URLs

Function reference
http://codex.wordpress.org/Function_Reference/wpdb_Class#INSERT_rows

Beginner guide
http://www.wpbeginner.com/wp-tutorials/useful-wordpress-configuration-tricks-that-you-may-not-know/


Custom fileds
http://millionclues.com/problogging/wordpress-tips/wordpress-custom-fields-tutorial-for-total-newbie/
Featured Gallery
http://www.featuredcontentgallery.com/
http://millionclues.com/problogging/wordpress-tips/custom-image-and-link-for-each-post-using-custom-fields/
Custom fileds
http://codex.wordpress.org/Using_Custom_Fields
Custom fileds
http://perishablepress.com/press/2008/12/17/wordpress-custom-fields-tutorial/
Top 10 galleries
http://techpp.com/2009/06/18/top-10-wordpress-gallery-plugins/
Galleries
http://codex.wordpress.org/Photoblogs_and_Galleries
http://smartboydesigns.com/2009/05/08/7-superb-wordpress-photo-gallery-plugins/
http://en.support.wordpress.com/images/gallery/

Themes
http://themeforest.net/

Resources
http://erkcm.wordpress.com/2010/03/29/300-resources-to-help-you-master-wordpress/

Clear history in linux

Hi,
When you connect to remote host using shell, then make sure to clear the history before you logout.
#command to clear the history is
history -c && rm -f ~/.bash_history

#Shell commands ref:
http://www.blogger.com/publish-confirmation.g?blogID=6810438578552048741&postID=843161968983163768×tamp=1272031182981&javascriptEnabled=true

Get full url with http or https protocol

/**
*
* @get the full url of page
*
* @return string
*
*/
function getAddress()
{
/*** check for https ***/
$protocol = $_SERVER['HTTPS'] == 'on' ? 'https' : 'http';
/*** return the full address ***/
return $protocol.'://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
}

/*** example usage ***/
echo getAddress();

?>

Drupal Front Page with multiple views content

I have posted one topic regarding how to load the multiple views in to single page ie:page-front.tpl.php .
In this example you have to create view name Mobile_applications and with in this view you have to create two page views those ids page_1 and page_2.

Now you can call those views using the fallowing code in page.tpl.php
//This is used to display the view in a page
$viewName = 'Mobile_applications';
$output = views_embed_view($viewName,'page_1');
echo "

Applications for your phone

";
print $output;

$output1 = views_embed_view($viewName,'page_2');
echo "

Top rated

";
print $output1;

?>

Center your block vertically using css

http://blog.themeforest.net/tutorials/vertical-centering-with-css/

Drupal display taxonomy terms for particular vocabulary

$vid = 3; /* <---- put correct vocabulary ID here */
$terms = taxonomy_get_tree($vid); /* need code from below to handle nesting */
print "

";
foreach ( $terms as $term ) {
$count = db_result(db_query("SELECT DISTINCT COUNT(nid) FROM {term_node} WHERE tid = %d ", $term->tid));
if ($count) { /* don't show terms with 0 count */
print "
• ".l($term->name .' ('. $count .')', "taxonomy/term/$term->tid") ."
";//this creates a link to the term
}
} /* end foreach */
print "

";
?>

Change date format in excel sheet

Hi,
I always prepare my documents in excel and i like it. I faced the problem when entering dates in the column, those are always formated to mm/dd/yy format even i entered in whatever format.
The solution i got is : Select formtat cells -> numbers -> date -> select custom format

Drupal load block content in any page

To Load block content in any page use below code in drupal

$blockView = module_invoke(, 'block', 'view', );
print($blockView['content']);

Where modulename is the type of the block, i.e you can create blocks in different ways like using views module, using taxonomyblock module etc. and delta is the numeric id of the block.

Example: below is the code to call a block which was generated using taxonomymenu block module.
$blockView = module_invoke('taxonomyblocks', 'block', 'view', 2);
print($blockView['content']);
?>


Display blocks based on some content types
$match = FALSE;

// block is visible on the content types entered here
$types = array('story' => 1, 'page' => 1);
$url = request_uri();

if ((arg(0) == 'node') && is_numeric(arg(1))) {
$node = node_load(arg(1));
$match = isset($types[$node->type]);
}

// block is invisible on URLs entered here
if (strpos($url, "edit")) {
$match = FALSE;
}

// copy paste these for additional URLs
if (strpos($url, "admin")) {
$match = FALSE;
}

return $match;
?>

Reference
http://drupal.org/node/26502
http://drupal.org/node/345361

Secure files transfer through SSH

http://www.unixwiz.net/techtips/putty-openssh.html
http://www.lesbell.com.au/Home.nsf/b8ec57204f60dfcb4a2568c60014ed0f/ed0d3f0199e49f57ca25734000023a77?OpenDocument


Some times you need to login two hosts.

First login:
ssh pete2@stickerguy.net
password:


su
root password:

Next server
ssh stickerguy@web2.greatbasin.net -p 2222
password:

Now you connected two hosting servers and you are in second server. To come out of second server press exit.

The below command will copy the first server files to second server.
scp -r pete2@stickerguy.net:/usr/local/lib/php/Services/ ./Services/

Drupal get term details for particular node you are viewing

$terms = taxonomy_node_get_terms($node);
print_r($terms);

Make will_paginate as ajax pagination

Add below code in your public/javascripts/application.js

document.observe("dom:loaded", function() {
// the element in which we will observe all clicks and capture
// ones originating from pagination links
var container = $(document.body)

if (container) {
var img = new Image
img.src = '/images/spinner.gif'

function createSpinner() {
return new Element('img', { src: img.src, 'class': 'spinner' })
}

container.observe('click', function(e) {
if (e.element().match('img'))
var el = e.element().ancestors()[0]
else
var el = e.element()
if (el.match('.pagination a')) {
el.up('.pagination').insert(createSpinner())
new Ajax.Request(el.href, { method: 'get' })
e.stop()
}
})

}
})

In app/controllers/controller.rb file add below

def product

@similar_products = Product.paginate(:per_page => 4,:page=>params[:similar_products_page],:conditions => ["shopping_category_id = ? and id != ?", @product.shopping_category_id, @product.id])

@featureproduct = Product.paginate(:per_page =>1, :page=>params[:featureproduct_page], :conditions => ["featured = ? and id != ?", 1, @product.id], :order=>'rand()', :limit => 3)

if params[:similar_products_page]
respond_to do |format|
#format.html
format.js {
render :update do |page|
# 'page.replace' will replace full "results" block...works for this example
# 'page.replace_html' will replace "results" inner html...useful elsewhere
page.replace_html 'related', :partial => 'related_products'
end
}
end
end

if params[:featureproduct_page]
respond_to do |format|
#format.html
format.js {
render :update do |page|
# 'page.replace' will replace full "results" block...works for this example
# 'page.replace_html' will replace "results" inner html...useful elsewhere
page.replace_html 'featured', :partial => 'product_featured'
end
}
end

end
In app/views/products/_product_featured.rb
<%= will_paginate @featureproduct, :param_name => 'featureproduct_page', :prev_label => image_tag('shopping/left_arrow.jpg'), :next_label => image_tag('shopping/right_arrow.jpg'), :page_links=>false%>


In app/views/products/_related_products.rb
<%= will_paginate @similar_products,:param_name => 'similar_products_page' %>

Now your pagination become ajax.

Multiple paginations in single page using will paginate

If you want to display multiple paginations in a single page then you have to change the detault page parameter. to change the default :page => params[:page] use below process

In controller add below
@featured = Product.paginate(:page => params[:featured_page])
@related = Product.paginate(:page => params[:related_page])

In view add below
<%= will_paginate @featured, :param_name => 'featured_page' %>
<%= will_paginate @related, :param_name => 'related_page' %>

Linux ssh Tips

Connect to ssh

You can connect to ssh using root@hostname.com If you have root access

If you dont have root access then do as below

1. First login ssh user@host1.com
2. su
3. Password: root password
After you login to host1's root.

then ssh user@host2.com -p 2222
host2password :

Now you logged into host2 from host1's root.

To come out to host1. use exit.

stickerguy@web2.greatbasin.net




locate is the command to search any folder or files.

Drupal usefull reference URLs

Usefull modules
Handbooks
http://drupal.org/handbooks

http://www.nicklewis.org/40-essential-drupal-6-modules

http://www.eadhoc.com/2010/03/drupal-terminology.html

Node auto term.It will create categories automatically when node contetn added.
http://www.facebook.com/note.php?note_id=196164430516

Node autotem
http://blog.adyax.com/2009/03/english-drupal-tutorial-node-auto-term-taxonomy-tips-and-jquery-menu-api-in-use/


Drupal 6
http://drupal.org/node/733182

Module functions
http://drupalcontrib.org/api/drupal/contributions--nat--nat.module/6


Taxonomy
http://drupal.org/node/2498

Reasons for why you use drupal
http://www.tajahdev.com/Resource/drupal.htm


15 Usefull views modules
http://ntt.cc/2009/01/28/15-userful-views-module-for-drupal.html

Views theming
http://www.packtpub.com/article/drupal-6-attachment-views-page-views-theming

http://realtech.burningbird.net/content-management/planet-drupal-entries/drupal-views-and-taxonomy-pages

http://zugec.com/drupal/theme-wizard-in-views-with-drupal-5

Advanced taxonomy term blocks
http://www.pixelclever.com/documentation-advanced-taxonomy-blocks-module-drupal-6

Views Help
http://views-help.doc.logrus.com/
http://drupal.org/node/59157

http://drupal.org/files/issues/nat-views-support-term-node-count_1.patch

Copying files from one host to another with scp command

Best Reference

http://www.lesbell.com.au/Home.nsf/b8ec57204f60dfcb4a2568c60014ed0f/04eaff076bce249dca256fb6007f53e5?OpenDocument

Copy entire folder with all files and subfolders
user@user:~$ scp -r /var/www/localdir/ user@192.168.10.150:/var/www/


In windows
Putty and pscp are excellent tools for ssh and scp operations in windows os.
Download putty and pscp softwares from http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
They are self executable files so no need to install those just place in some folder ex: c:\programfiles\putty folder and set the path in command prompt.

open command prompt (DOS Prompt)from start -> run -> cmd

set PATH=C:\path\to\putty\directory;%PATH%

So to copy the file /etc/hosts from the server example.com as user fred to the file c:\temp\example-hosts.txt, you would type:

pscp fred@example.com:/etc/hosts c:\temp\example-hosts.txt

To send (a) file(s) to a remote server:

pscp [options] source [source...] [user@]host:target

So to copy the local file c:\documents\foo.txt to the server example.com as user fred to the file /tmp/foo you would type:

pscp c:\documents\foo.txt fred@example.com:/tmp/foo

You can use wildcards to transfer multiple files in either direction, like this:

pscp c:\documents\*.doc fred@example.com:docfiles
pscp fred@example.com:source/*.c c:\source

Copy entire folder from remote server to local computer along with files and subfolders
pscp -r user@example.com:source/* c:\source

Ref : http://www.jfitz.com/tips/ssh_for_windows.html

Export and import database to and from remote servers through telnet

Hi, If you want to take database backup from one server and import it into another remote server use the below process.


Import command at terminal or dos
mysql -u user_login -p database_name < /path_to_the_file/my_backup.sql

Export command at terminal or dos
mysqldump -u user_login -p database_name > /path_to_the_file/my_backup.sql

Database Backup
connect to remote host with SSH from termail using below command
#ssh user@host.com
password:
After login, crate one folder to store the backup file and make it writeble, then run the beloc ommand to take backup for the whole database
#mysqldump -u dbusername -p dbname > dbbackup.sql
It will ask you the dbpassword

After download ddbackup.sql and transfer to new host where you have to set up the database..

connect to remote host with SSH
#mysql -u dbusername -p dbname -e 'source dbbackup.sql'
It wil ask you the dbpassword.


The other way, which is even cooler, and more secure, assuming you have ssh access on both machines (this, again, is a direct dump-to-import):

mysqldump -ux -px database | ssh me@newhost "mysql -ux -px database"

This will dump the data to stdout, pipe it to ssh @ the newhost, and into mysql. Of course, replace all x's with username's and password.


If you want to keep two databases equal, you can use rsync (if your system supports it) to do it by creating a simple script:

rsync you@yourserver::share/path/to/mysql/data/* /path/on/the/other/server/

that you call with a cron job every 10 minutes/1 hour/1day/...

This way, whenever your database change, rsync will find the difference and would transfer ONLY the bytes that have changed.

Ref: http://www.webhostingtalk.com/archive/index.php/t-226992.html