Deploying a web application to Liberty

You can manually configure your server.xml file to meet the specifications of your application. By deploying a helloworld.war application, you can learn how to manually change server configurations in Liberty.

Before you begin

To complete this task, you must provide a helloworld.war application that uses a simple servlet to display a message on your browser. You can create any other messages to be displayed. The coding of this application is not described within the Liberty documentation.

However, the Open Liberty Building a web application with Maven guide provides a similar introduction to deploying an application on Liberty and also includes instructions for creating a sample application. You can complete that guide as an alternative to supplying your own helloworld.war application and following the steps in this task.

About this task

When you deploy a web application to Liberty by using the developer tools, all configurations that are related to the application are automatically enabled in the server.xml file. However, you can also configure the server.xml file manually by completing the following steps.

This example uses the helloworld.war application and can be accessed by using http://localhost:9090/helloworld. In this example, a Liberty server instance is created, and then its default HTTP port is changed to 9090, and then an application is deployed to it.

Procedure

Create a server named hwserver by using the command server create hwserver.
Copy the helloworld.war application into the /usr/servers/hwserver/apps directory; this directory was created by the server create command in step 1.

In the server.xml file that was created by the

server
create

command, change the default HTTP port of the server hwserver to 9090 by replacing the attribute value httpPort="9080" with httpPort="9090".

<server description="new server">

  <!-- Enable features -->
    <featureManager>
      <feature>jsp-2.2</feature>
    </featureManager>

    <httpEndpoint id="defaultHttpEndpoint"
      host="localhost"
      httpPort="9090"
      httpsPort="9443" />
</server>

Configure the application by updating the server.xml in either of the following ways:
- Define the application by using a webApplication element.
```
<server description="Hello World Server">

 <featureManager>
   <feature>servlet-3.0</feature>
 </featureManager>

<httpEndpoint id="defaultHttpEndpoint" host="*" httpPort="9090" />

<webApplication contextRoot="helloworld" location="helloworld.war" />

</server>
```
- Define the application by using an application element.
```
<server description="Hello World Server">

 <featureManager>
   <feature>servlet-3.0</feature>
 </featureManager>

<httpEndpoint id="defaultHttpEndpoint" host="*" httpPort="9090" />

<application context-root="helloworld" type="war" id="helloworld"
    location="helloworld.war" name="helloworld"/>

</server>
```
The webApplication element can use the same child elements as the application element, except for context-root and type. The two elements do not work together for a context-root, and if both an application and webApplication element define the same context-root, only one is used and an error is displayed.
The context-root attribute specifies the entry point of the deployed application. The entry point of a deployed application is determined in the following precedence:
- context-root in the server.xml file
- application.xml, if an EAR application
- ibm-web-ext.xml, if a web application
  Note: The context-root attribute on the web-ext element underneath the application element in the server.xml file.
- name of the application in the server.xml file, if a web application
- Manifest.MF, if a WAB application
- Directory name or the file name relative to the drop-ins directory of Liberty
Note: In an application server server.xml configuration, the application element can contain a context-root tag. This context-root tag is applicable in combination with the tag type="war". For all other application types, the context-root element has no effect.
It is not possible to override the context-root for either an EAR application, or an EBA application. It is only possible to do an override for a stand-alone war file, or webApplication.
Start the server in foreground by using the command server run hwserver.
Test the application at http://localhost:9090/helloworld.
Optional: Stop the server if you do not need it.