Using OGCE's JavaScript API to MyProxy

We are in the process of releasing a JavaScript COG API, Cyberaide, that works with common Grid services like MyProxy, GRAM, and GridFTP. Our goal is to provide a method for embedding these calls into many different frameworks, including non-Java languages and tools such as PHP and Ruby on Rails. We are want to provide tools that can be used to build Open Social gadgets that perform Grid operations.

For a fuller description of the project, see http://cyberaide.org/projects/cyberaide/cyberaide-javascript. To browse or download the working version of the code, see http://code.google.com/p/cyberaide/. The examples (very actively developed) can be built using one command,

mvn clean install

from the cyberaide source's top level directory. Edit the top level pom.xml file's properties first. Use the version of Maven provided in the download. You can also rebuild portions of the system with the command

mvn clean install -f client/pom.xml

where client is one of the project modules. After you build everything, start up Tomcat (use the startup-tomcat.sh convenience script). Point your browser to http://localhost:8080/jsportal.html to see some examples.

To shut down everything, you can use the shutdown scripts (shutdown-tomcat.sh and shutdown-mediator.sh). To see debugging information, check out the log files: agent.log and mediator/mediator.log.

MyProxy API Example
The full example is called "MyProxyGadget.html" and is located in the subdirectory client of the source code. To start, you need a set of HTML input fields as usual:

<table>
<tr>
<div id="authStatus" name="authStatus"/>
</tr>
<tr>
<td>Myproxy Server Host:</td>
<td><input name="host" type="text" id="myproxy.host" size="50" value="myproxy.teragrid.org"/></td>

</tr>
<tr>
<td>Myproxy Server Port:</td>
<td><input name="port" type="text" id="myproxy.port" size="50" value="7512"/></td>
</tr>
<tr>
<td>Myproxy Username:</td>
<td><input name="user" type="text" id="myproxy.user" size="50"/></td>
</tr>
<tr>
<td>Myproxy Passphrase:</td>
<td><input name="password" type="password" id="myproxy.password" size="50"/></td>
</tr>
</table>
<input name="button0" type="button" class="runButton" id="button0" onclick="auth();return false" value="Authenticate"/>

Next, you need to import the COG JavaScript library:

<script type="text/javascript" src="CogKit2.js"/>

Now implement the auth() method from your button's onclick attribute. This should of course be located in a section <script language="javascript" > section.

/* Initialize the JavaScript COG */
var url = "../agent/services/agent";
var jscog = new CogKit2(url);
var authStatus = false;

//Define your auth function here.
function auth(){

//These point to the elements in the table above.
var host = document.getElementById("myproxy.host").value;
var port = document.getElementById("myproxy.port").value;
var user = document.getElementById("myproxy.user").value;
var password = document.getElementById("myproxy.password").value;

//A little window dressing
document.getElementById("authStatus").innerHTML=" Authenticating";

//Now invoke the JS CoG auth method from the imported library.
jscog.auth(host, port, user, password, authResponse);
}

The last argument, authResponse, is a callback function that you can use to determine if authentication was successful or not. A sample implementation is shown below.

/*
* the authenticate callback function
*/
function authResponse(ret) {
if(ret){
authStatus = true;
document.getElementById("authStatus").innerHTML="Authenticated successfully!";
document.getElementsByName("password")[0].value="";
} else{
authStatus = false;
document.getElementById("authStatus").innerHTML="Failed to Authenticate!";
document.getElementsByName("password")[0].value="";
}
}

We'll look at more functions in upcoming posts.