Tag: server

HTTP Cookie Header

Obviously “Cookies” have a lot of advantages in web applications to maintain “state”, unfortunately using standard server configurations leads to even static content serving them up un-necessarily wasting some (minimal) bandwidth.

Adding the following to the Apache httpd.conf file is a start:
#Remove Cookie from all static content (except HTML as javascript could use it)
<FilesMatch "\.(html|htm|js|css|gif|jpe?g|png|pdf|txt|zip|7z|gz|jar|war|tar|ear|java|pac)$">
<IfModule header_module>
Header unset Cookie
</IfModule>
</FilesMatch>

REFERENCES:

Cheers!

Web Proxy Autodiscovery Protocol (WPAD)

If you take a close look at your logs you may occasionally see requests for a file named wpad.dat. This file is related to automatic proxy configuration in many browsers.

To provide this capability to your users and website,

  1. DNS:

    Default behavior is to traverse the domain in reverse, looking for one with a file named /wpad.dat

    Example (using my domain for example):
    wpad.www.giantgeek.com
    wpad.giantgeek.com
    wpad.com

  2. Then in httpd.conf, set the MIME type:
    AddType application/x-ns-proxy-autoconfig .pac
  3. Also in httpd.conf, add a redirect to the actual file you wish to use.
    Redirect permanent /wpad.dat http://www.giantgeek.com/proxy.pac
  4. In the new file, add the following default contents, modify if you use a proxy:

    /* 'proxy.pac' - This is the main function called by any browser
    NOTE: there is NO proxy!
    */
    function FindProxyForURL(url, host)
    {
    return “DIRECT”;
    } // End function FindProxyForUrl

REFERENCES:

Enabling .htaccess in Apache 2.x

There may come a time when you want to change server behaviors for a specific path on your web server. Often times this becomes necessary if you host web sites that the customer wants to manage externally.

There are only a few small changes required:

  1. In your httpd.conf file…
    # use .htaccess files for overriding,
    AccessFileName .htaccess
    # and never show any file starting with .ht
    <files ~ "^\.ht">
    Order allow,deny
    Deny from all
    </files>
  2. The for the paths (or virtual hosts, you’ll need to add this line):
    AllowOverride All
  3. Add the appropriate .htaccess files where needed.

DISCLAIMER: This technique CAN result in performance improvements, but should be put in your main server configuration file (httpd.conf), rather than in .htaccess files. .These files, by their very nature, cause performance degradation on your website, and so should be avoided whenever possible as they require an increase in file I/O (reads) on the server.

REFERENCES:

Accessing VirtualBox client from host

Assuming that you are a developer on Windows that run a VirtualBox instance for a server, you might find it difficult to browse/access the “virtual” server that are running as a client. Here’s an example of the config required for standard HTTP, HTTPS and SSH, you can easily expand for other services as needed. Example assumes that your client is named “Ubuntu64”, you need to change appropriately for each client.

NOTE: if you are using a Linux host, the commands are similar.

cd C:\Program Files\Oracle\VirtualBox
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/ApacheHTTP/HostPort 80
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/ApacheHTTP/GuestPort 80
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/ApacheHTTP/Protocol TCP
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/ApacheHTTPS/HostPort 443
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/ApacheHTTPS/GuestPort 443
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/ApacheHTTPS/Protocol TCP
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/Tomcat/HostPort 8080
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/Tomcat/GuestPort 8080
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/Tomcat/Protocol TCP
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/SSH/HostPort 22
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/SSH/GuestPort 22
VBoxManage.exe setextradata "Ubuntu64" VBoxInternal/Devices/pcnet/0/LUN#0/Config/SSH/Protocol TCP
VBoxManage.exe getextradata "Ubuntu64" enumerate

NoMachineNX – SSH Remote Desktop for Linux/Unix

I’ve used a variety of means to connect to remote machines. Long ago, PCAnywhere was common place, later replaced by VNC and Windows Remote Desktop (RDP). As I’ve migrated nearly all of my work to Ubuntu, I’ve found that VNC is generally too slow, and SSH alone only gives access to my command line environment. NX over SSH allows for efficiently visual access to my entire desktop and all accessories remotely, regardless of my client system.

Setup on the server/host system only takes a few minutes, but is only available on Linux and Solaris. Installation of SSH on the host is required first.

Setup of the client is even easier, and is available for Linux, OS/X and Windows.

NOTE: A “NX Free Edition” is available for use.

REFERENCES:

Custom 404 Page for Tomcat web applications

This is a relatively common problem in JSP based apps as you need to understand the configuration. It’s further complicated if you use Apache HTTPD in front of the Apache Tomcat server to process requests as you need to know where each request is processed.

For this example, we will use the standard 404 error, but you can also intercept other errors for custom pages.

  1. create 404.jsp:

    <% final SimpleDateFormat simpleDate = new SimpleDateFormat("EE MMM dd yyyy hh:mm:ss aa zzz");
    final String dttm = simpleDate.format(new Date()); %>
    <html>
    <title>404 Not Found</title>
    <ul>
    <li>Time: <%= dttm %></li>
    <li>User-Agent: <%= request.getHeader("User-Agent") %></li>
    <li>Server: <%= request.getServerName() %></li>
    <li>Request: <%= request.getRequestURI() %></li>
    <li>Remote: <%= request.getRemoteAddr() %></li>
    <li>Referer: <%= request.getHeader("Referer") %></li>
    </ul>
    </html>
  2. in WEB-INF/web.xml – add the following (NOTE: location within the file is important but outside the scope of this post)

    <error-page>
    <error-code>404</error-code>
    <location>/404.jsp</location>
    </error-page>
  3. You might want to force the HTTP Header to give something other than a ‘404 status’ code, otherwise MSIE will show an unstyled ‘friendly error message’ if the user has not turned off the default setting. Unfortunately, this also means that search engines might index these pages that should not exist.

REF:

Enable HTTP GZip compression on Apache Tomcat

This one escaped me for a long time and I never saw a decent example of it in any of the documentation.

GZip compression saves on network bandwidth as files are compressed during transport between the HTTP Server and browser/client. If you already use Apache HTTP or a similar webserver to front Tomcat, this is not always necessary, but in cases where you expose your appserver directly, even if it is just for testing, you may want to add this configuration item as it increases the perceived speed of the application.

The solution is simple:

  1. To be safe, first stop the server and backup your configuration files
  2. Look in the /TOMCAT/conf installation folder.
  3. In the ‘server.xml’ file, you will find a line resembling…
    <Connector port="8080" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" />
  4. This one controls the HTTP/1.1 connections, add a new value to the list…
    compression="on"
  5. NOTE You might also see a value for for AJP/1.3, unfortunately compression only works for HTTP:
    <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />
  6. Restart your server.

Cheers

Enable .htaccess on Apache HTTPD Server

Occasionally, there becomes a need to expose the use of the .htaccess file to the domains hosted on your Apache server. This technique is particularly useful when you host websites for external clients (or developers).

The steps to enable it are relatively easy,

  • Uncomment the ‘httpd.conf’ line that reads as:

    LoadModule rewrite_module modules/mod_rewrite.so

  • Review (and replace as appropriate) all cases of :

    AllowOverride None with AllowOverride All

    in the following files:
    httpd.conf, /extra/httpd-vhosts.conf, /extra/httpd-autoindex.conf and any related files you may be using.

  • Add the .htaccess file into the appropriate websites/folders
  • Restart the server to accept the changes

NOTE: If you develop or host on Windows, you’ll likely have problems creating the file because there is no filename, just a file extension. You can create (or download) it from any non-Windows host and use it without additional changes. Apache does let you use a different filename, but you also need to be careful to update related security configuration that is used to prevent download of such files.

Happy hosting!

Open Source FTP Client (and Server)

At one time, FTP was the only means available to move large files, times have changed but the need still exists, especially for developers like myself.

For years I’ve happily used FileZilla for my FTP needs, the client is available on most platforms. There is also a server available for Windows as most Linux variants already provide FTP.

Happy file transfers!

MySQL (Windows) service startup error 1067

I’ve installed and managed dozens of MySQL installations for several years, occasionally it seems that an install just doesn’t run like it has in the past.

Recently I had a problem where the service would not start (Error 1067) on Windows Server 2003 (R2)… which is running under VMWare. After checking the obvious places and turning up nothing I started down the list of potential solutions exposed by Google search.

The ultimate solution it seems is that the ‘my.ini’ file needed to include the specific path information required by the service…. without it the service would not start.

Here’s my current file (c:\windows\my.ini) for reference:

[WinMySQLAdmin]
Server=C:/mysql40/bin/mysqld-nt.exe
[mysqld]
basedir=c:/mysql40
datadir=c:/mysql40/data

For the really observant readers of this entry… you will notice that this is for MySQL 4.0 (which is no longer officially supported). It’s mostly used as it is widely compatible across various host systems that are sometimes problematic with newer releases.

Cheers.