Image Thumbnails

30 09 2008

So I have a directory on my server with several (more than 50) sub-directories filled with pictures. Obviously this is a lot of pictures, and since I did not name the images as I uploaded them, I have no idea what’s what. I just know where and when they were taken from the folder titles. I thought something that would generate thumbnails would be great for browsing through the pictures, especially if you were looking for a certain image. So I found this script, and added a two lines that would automatically create a thumbs directory in the Image directory, and that would redirect to the newly generated html page.

Basically what the script does is resize all the .jpg files in the directory, and saves them in the newly created thumbs directory. It then creates a file called gallery.html which shows all the new thumbnails with links to their originals. It does pretty much exactly what I was looking for. Originally the script was called create_thumbs.php, but I renamed it to index.php so it would load each time you opened the folder. In case images had been added. Then I added a redirect line so that it would automatically redirect to gallery.html. This is what I ended up with.
<?php
/*
This is the PHP code for the How to Create Thumbnail Images using PHP Tutorial
This script creates all of the thumbnail images and the gallery.html page.
Note: Make sure that PHP has permission to read and write
to the directory in which .jpg files are stored and the directory
in which you're trying to create thumbnails.
You may use this code in your own projects as long as this
copyright is left in place. All code is provided AS-IS.
This code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Copyright 2007 WebCheatSheet.com
*/

header( 'Location: ./gallery.html' ) ;
mkdir("./thumbs", 0777);
function createThumbs( $pathToImages, $pathToThumbs, $thumbWidth )
{

// open the directory
$dir = opendir( $pathToImages );

// loop through it, looking for any/all JPG files:
while (false !== ($fname = readdir( $dir ))) {
// parse path for the extension
$info = pathinfo($pathToImages . $fname);
// continue only if this is a JPEG image
if ( strtolower($info['extension']) == 'jpg' )
{
echo "Creating thumbnail for {$fname} <br />";

// load image and get image size
$img = imagecreatefromjpeg( "{$pathToImages}{$fname}" );
$width = imagesx( $img );
$height = imagesy( $img );

// calculate thumbnail size
$new_width = $thumbWidth;
$new_height = floor( $height * ( $thumbWidth / $width ) );

// create a new tempopary image
$tmp_img = imagecreatetruecolor( $new_width, $new_height );

// copy and resize old image into new image
imagecopyresized( $tmp_img, $img, 0, 0, 0, 0, $new_width, $new_height, $width, $height );

// save thumbnail into a file
imagejpeg( $tmp_img, "{$pathToThumbs}{$fname}" );
}
}
// close the directory
closedir( $dir );
}

function createGallery( $pathToImages, $pathToThumbs )
{
echo "Creating gallery.html <br />";

$output = ";
$output .= "<head><title>Thumbnails</title></head>";
$output .= "<body>";
$output .= "<table cellspacing=\"0\" cellpadding=\"2\" width=\"500\">";
$output .= "<tr>";

// open the directory
$dir = opendir( $pathToThumbs );

$counter = 0;
// loop through the directory
while (false !== ($fname = readdir($dir)))
{
// strip the . and .. entries out
if ($fname != '.' && $fname != '..')
{
$output .= "<td valign=\"middle\" align=\"center\"><a href=\"{$pathToImages}{$fname}\">";
$output .= "<img src=\"{$pathToThumbs}{$fname}\" border=\"0\" />";
$output .= "</a></td>";

$counter += 1;
if ( $counter % 4 == 0 ) { $output .= "</tr><tr>"; }
}
}
// close the directory
closedir( $dir );

$output .= "</tr>";
$output .= "</table>";
$output .= "<br />";
$output .= "<a href = 'http://thesupportdepartment.com/Pictures/Willem Sr Pictures'>Return To Pictures</a>";
$output .= "</body>";
$output .= "</html>";

// open the file
$fhandle = fopen( "gallery.html", "w" );
// write the contents of the $output variable to the file
fwrite( $fhandle, $output );
// close the file
fclose( $fhandle );
}

// call createThumb function and pass to it as parameters the path
// to the directory that contains images, the path to the directory
// in which thumbnails will be placed and the thumbnail's width.
// We are assuming that the path will be a relative path working
// both in the filesystem, and through the web for links
createThumbs("./","thumbs/",100);
// call createGallery function and pass to it as parameters the path
// to the directory that contains images and the path to the directory
// in which thumbnails will be placed. We are assuming that
// the path will be a relative path working
// both in the filesystem, and through the web for links
createGallery("./","thumbs/");
?>

You place it in the folder where the images are located, name it index.php, make sure the folder is chmodded to 777 and when you navigate to that folder, it will create a thumbs directory and the gallery.html file. Then it will redirect to your gallery.

Finally, since I had to place this file in a lot of directories, I placed a copy of the file in the parent directory. Changed to the parent directory, and issued the following Unix command. Then I deleted the copy located in the parent directory.

sudo for dir in *; do [ -d “$dir” ] && cp index.php “$dir” ; done

I got the script from here.





A better way!

20 09 2008

Well, I was told by a reader that .htaccess is not a very secure way to block off parts of your website. Since I am busy learning everything for the first time, I was willing to take his advice and was able to use httpd.conf to restrict access. Also, he showed me a way that sends passwords encrypted, rather than in plain text. Anyway, I’d like to thank Bob for this advice, and here is a much better way to block off parts of your site…
(Please note the following is directly quoted from Bob’s comments as to not take credit for this myself.)

You should never use .htaccess files unless you don’t own the server and don’t have access to the main server configuration file (httpd.conf).

See the Apache documentation article When (not) to use .htaccess files: http://httpd.apache.org/docs/2.2/howto/htaccess.html#when

Basically, httpd.conf would, in your case, look something like:

<Directory>

AuthType Basic
AuthName “SECRET SQUIRREL RESTRICTED ACCESS AREA”
AuthUserFile /etc/apache2/passwd/passwords
Require valid-user

</Directory>

The /var/www/music is the directory you want to password.
AuthType Basic is basic HTTP authentication, as opposed to AuthType Digest which uses MD5 authentication.
AuthName is simply the text that will be displayed in the password request box.
AuthUserFile is where the passwords are stored, which you create using the htpasswd command.
And finally, Require valid-user means that anyone in the password file can get in. Or, you can specify a particular name, such as Require Willem.

See Apache access control for more info: http://httpd.apache.org/docs/2.2/howto/auth.html#gettingitworking

Bob

But wait! There’s an even better way!

AuthType Basic sends the password in clear text, so it’s fairly unsecure. AuthType Digest uses a little bit of encryption with an MD5 checksum and a once-used number and does not send the password in clear text, so it’s more secure.

And, since AuthType Digest is really no harder to use than AuthType Basic, you might as well get the enhanced security. The only real drawback that I see with AuthType Digest is that really old browsers don’t support it. But unless you’re using a browser from 2004, that’s not much of a problem )

Anyway, AuthType Digest is really similar to AuthType Basic except that the way you create a password is slightly different and the httpd.conf entry refers to ‘Digest’, rather than ‘Basic’.

For example, to use AuthType Digest to password-protect the ‘private’ realm and directory /var/www/music and only let in user Joe. First, create a password for joe:

htdigest -c /etc/apache2/passwordfile private joe
(note: location of password file is just an example and doesn’t have to be at that location or use that file name)

Then edit httpd.conf file to require password to access /var/www/music:

<Directory /var/www/music>
AuthType Digest
AuthName “private”
AuthDigestDomain /music/
AuthUserFile /etc/apache2/passwordfile
Require user joe
</Directory>
(Note: replace ( and ) with in the real httpd.conf file. I just used parentheses here so the HTML wouldn’t be stripped out by the blog software).

See here for more techie details: http://httpd.apache.org/docs/2.2/mod/mod_auth_digest.html

Good luck, and enjoy your Ubuntu server! I sure enjoy mine! )

Bob

One more thing on Digest. It is an Apache mod-file, which Ubuntu does not have enabled by default.

If you look in /etc/apache2/mods-available, you will see it: auth_digest.load

But, if you look in /etc/apache2/mods-enabled, it isn’t there by default in Ubuntu server.

But enabling it is easy. If you notice that in /etc/apache2/mods-enabled there aren’t actually any files, just symbolic links to the /etc/apache2/mods-available directory (do an ls -l). So, to enable the auth_digest.load, all you have to do is create a symbolic link like so:

cd /etc/apache2/mods-enabled
sudo ln -s ../mods-available/auth_digest.load auth_digest.load

Then restart Apache:
sudo /etc/init.d/apache2 restart

Have fun! )

Bob

I can verify that this did indeed work, and once again, thanks to Bob for showing me a better way.





.htaccess

14 09 2008

So after I made my music available in my web root, I felt it necessary to password protect it. I don’t want anyone to download my music or stream it or anything like that. No one except me, that is. No illegal activity should be coming from my server I figured. So I thought of the most basic way to do it which was htaccess.

Basically, you create a file called .htaccess with certain parameters. Here’s mine:

AuthType Basic
AuthName "Music"
AuthUserFile /var/.htpasswd
require valid-user

I’m not exactly sure what

AuthType

is, but

AuthName

is whatever you wanna call the folder you’re protecting. It doesn’t change the folder name, this is just what shows up in the little login window that pops up when you navigate to this folder.

AuthUserFile

is where the .htpasswd file is stored. The .htpasswd file specifies which user and password combinations are allowed to access this folder.

require valid-user

just lets it know that any valid user specified within the .htpasswd file is required for access.

In .htpasswd, each individual user should have his own line, and username and password should be seperated by a colon. i.e.

username:password
username:password

Finally, in your apache settings, specifically if you’re using Ubuntu the file will be located at /etc/apache2/sites-available/default. Find the line

AllowOverride None

and change it to

AllowOverride All





Worth a mention

10 09 2008

Well, this is kind of short, but I got wordpress loaded on the server. I was having trouble accessing the MySQL database. What happened was, I forgot the password I originally set for the root user, and thought I could just use my username and password. So all I had to do was reinstall MySQL and actually remember what the password was this time. I assume you already know how to install wordpress. If not there are plenty of help topics on it.

I know there is a command for resetting the MySQL root user password, I just forgot what it is.





External HDD

9 09 2008

So the most recent thing I’ve done is add on a 1TB external hard drive. This will be where basically all media such as photos and videos and music will be stored to be shared with the family.

When I first plugged in the drive, I couldn’t even move files on and off it. I wasn’t sure what was wrong, but eventually found out you have to make it your own. So you chown it by doing the following:

sudo chown -R user.user mountpoint

Where user is replaced with you username, in my case muzak, and mountpoint replaced with the location where the drive is mounted, in my case /media/disk.

This should’ve worked, only it didn’t. The problem was that the disk was using the FAT32 filesystem, which doesn’t support permissions. So basically what I had to do was reformat it. I opened up gparted,

sudo gparted

Navigated to the external disk and unmounted and reformatted it to ext3. After that I unplugged the disk and plugged it back in, ran the same command and everything was great.

Another way you can modify the permissions is to enter

sudo "filemanager"

filemanager being whatever you use to manage your filesystem, in my case dolphin. It will open up the filesystem, but you’ll be treated as the root user. You can now right click where the drive is mounted, in my case /media/disk, and click on the permissions tab. This is the thread where I got all my help from.





Let’s kick things off (VSFTPD)

8 08 2008

To start:
~Everything is installed on a Dell PowerEdge 2850 web server
~I installed Ubuntu 8.04 LTS Server Edition. You can download or request a CD be sent to you for free at http://www.ubuntu.com
~I plan on making this a ftp, LAMP, print, and mail server.

After downloading and installing Ubuntu, I thought it would be a good idea to install some sort of GUI, since I am not very knowledgeable in command line operating systems, and I did not feel like spending all the time learning. I decided to go with kubuntu. To install this I just had to enter the command:

sudo apt-get install kubuntu-desktop

Now that I had a GUI, it was time to get started. I figured the easiest thing to do would be to install the ftp client. It seemed pretty basic, and would allow me to back up other computers onto the server right away. I decided to go with vsftpd as this was said to be a reliable and light yet flexible client. To install this I entered the following command.

sudo apt-get install vsftpd

After a long time of trying to customize the config file myself, I was at the end of my fuse. I knew there had to be an easier way. So I searched a little bit on the internet and came accross Webmin. You can read more about what it is on the website, but basically it’s an easy way to manage various aspects of your server. This was pretty much exactly what I was looking for. I downloaded and installed it using this site as a guide.

Now that I had Webmin installed, I noticed it did not come with a module for vsftpd. Luckily someone had made one. Using this site as a guide, I was able to get it up and running.

The issue I was having with vsftpd was with security. I knew there were ways to lock users to their own folders and to create virtual users and all that, but I just could not figure it out. The Webmin module helped me figure that out to some degree. I was able to jail all users to their home directories, but I was never able to figure out how to create the virtual users, and from what I could tell, the module was no help whatsoever. So I decided to not worry so much about the virtual part, and just create local users. So I went into Webmin, and clicked System>>Users and Groups, and selected create new a new user. I noticed vsftpd had already created a user called virtual belonging to a group it had also created, also aptly named virtual. So I figured the “virtual” group had all the right settings. I created my own users and specified where their home directories were to be at. Logins from different machines proved successful, and users were not allowed outside their directories. Everything was great.

The next thing I decided to tackle was VNC. Since I am leaving for school the 14th, I figured I probably wouldn’t be done with this server before then, so I thought it would be nice to be able to work on it remotely from about 760 miles away. The VNC which was already loaded on the system required you to send out an invitation to whomever you wanted to connect to the server. This invitation is only valid for one hour or one login, whichever comes first. So this would require someone to send me an invitation everytime I wanted to work on the server, one phone call and hassle too much. So I looked a little, and found a client which could be started from the terminal. It runs with a single password, so if I know the password and the host, I can connect. This seemed alright for my purposes. I could log into the computer using PuTTY, and execute the command to start the VNC. This site explained, in a clear and concise manner (4 steps), how to set up x11vnc. After installing the client, I simply had to log into my router and open ports 5800 and 5900.

That’s pretty much how far I’ve gotten so far. This is pretty much going straight past all the struggles and searching and straight to the successes. I know this will help someone, even if it’s just me again in the future.