Sample use of the XL Deploy Generic plugin

This is an example of using the Generic Model plugin to implement support for a simple middleware platform. Deployment to this platform is done by simply copying a WAR archive to the right directory on the container. Resources are created by copying configuration files into the container’s configuration directory. The Tomcat application server works in a very similar manner.

By defining a container and several other CIs based on CIs from the Generic Model plugin, it is possible to add support for deploying to this platform to XL Deploy.

Defining the container

To use any of the CIs in the Generic Model plugin, they need to be targeted to a generic.Container. This snippet shows how to define a generic container as a synthetic type:

<type type="tc.Server" extends="generic.Container">
    <property name="home" default="/tmp/tomcat"/>
</type>

<type type="tc.UnmanagedServer" extends="tc.Server">
    <property name="startScript" default="tc/start.sh" hidden="true"/>
    <property name="stopScript" default="tc/stop.sh" hidden="true"/>
    <property name="restartScript" default="tc/restart.sh" hidden="true"/>
</type>

Note that the tc.UnmanagedServer CI defines a start, stop and restart script. The XL Deploy Server reads these scripts from the classpath. When targeting a deployment to the tc.UnmanagedServer, XL Deploy will include steps executing the start, stop and restart scripts in appropriate places in the deployment plan.

Defining a configuration file

The following snippet defines a CI based on the generic.CopiedArtifact. The tc.DeployedFile CI can be targeted to the tc.Server. The target directory is specified as a hidden property. Note the placeholder syntax used here.

<type type="tc.DeployedFile" extends="generic.CopiedArtifact" deployable-type="tc.File"
      container-type="tc.Server">
    <generate-deployable type="tc.File" extends="generic.File"/>
    <property name="targetDirectory" default="${deployed.container.home}/conf" hidden="true"/>
</type>

Using the above snippet, it is possible to create a package with a tc.File deployable and deploy it to an environment containing a tc.UnmanagedServer. This will result in a tc.DeployedFile deployed.

Defining a WAR

To deploy a WAR file to the tc.Server, one possibility is to define a tc.DeployedWar CI that extends the generic.ExecutedScript. The tc.DeployedWar CI is generated when deploying a jee.War to the tc.Server CI. This is what the XML looks like:

<type type="tc.DeployedWar" extends="generic.ExecutedScript" deployable-type="jee.War"
      container-type="tc.Server">
    <generate-deployable type="tc.War" extends="jee.War"/>
    <property name="createScript" default="tc/install-war" hidden="true"/>
    <property name="modifyScript" default="tc/reinstall-war" hidden="true" required="false"/>
    <property name="destroyScript" default="tc/uninstall-war" hidden="true"/>
</type>

When performing an initial deployment, the create script, tc/install-war is executed on the target container. Inside the script, a reference to the file property is replaced by the actual archive. Note that the script files do not have an extension. Depending on the target platform, the extension sh (Unix) or bat (Windows) is used.

The WAR file is referenced from the script as follows:

echo Installing WAR ${deployed.deployable.file} in ${deployed.container.home}

Defining a datasource

Configuration files can be deployed by creating a CI based on the generic.ProcessedTemplate. By including a generic.Resource in the package that is a FreeMarker template, a configuration file can be generated during the deployment and copied to the container. This snippet defines such a CI, tc.DeployedDataSource:

<type type="tc.DeployedDataSource" extends="generic.ProcessedTemplate" deployable-type="tc.DataSource"
      container-type="tc.Server">
    <generate-deployable type="tc.DataSource" extends="generic.Resource"/>

    <property name="jdbcUrl"/>
    <property name="port" kind="integer"/>
    <property name="targetDirectory" default="${deployed.container.home}/webapps" hidden="true"/>
    <property name="targetFile" default="${deployed.name}-ds.xml" hidden="true"/>
    <property name="template" default="tc/datasource.ftl" hidden="true"/>
</type>

The template property specifies the FreeMarker template file that the XL Deploy Server reads from the classpath. The targetDirectory controls where the template is copied to. Inside the template, properties like jdbcUrl on the datasource can be used to produce a proper configuration file.