Apache Karaf WAR Example

Abstract

As a polymorphic runtime, Apache Karaf is able to deploy and run lot of different kind of applications.

It's especially possible to deploy a web application packaged as a war, as you can do in any web container.

This example shows how to create a regular war to be deployed in Apache Karaf.

Artifacts

karaf-war-example-webapp is a regular simple war.
karaf-war-example-features provides a Karaf features repository used for deployment.

## Build

Simply use:

mvn clean install

## Feature and Deployment

You have three ways to deploy the example war.

Using the war deployer
Using the bundle:install shell command (with webbundle protocol)
Using the provided feature

WAR deployer

The WAR deployer allows you to directly hotdeploy war files, by simpling dropping the war files in the Karaf deploy folder.

To enable the WAR deployer, you have to install the war feature first:

karaf@root()> feature:install war

Then, simply drop the war file in the deploy folder:

$ cp examples/karaf-war-example/karaf-war-example-webapp/target/karaf-war-example-webapp-*.war $KARAF_HOME/deploy

You can then see the webapp deployed using the web:list command:

karaf@root()> web:list
ID  │ State       │ Web-State   │ Level │ Web-ContextPath           │ Name
────┼─────────────┼─────────────┼───────┼───────────────────────────┼──────────────────────────
102 │ Active      │ Deployed    │ 80    │ /karaf-war-example-webapp │ karaf-war-example-webapp

You can point your browser to [http://localhost:8181/karaf-war-example-webapp].

Shell command (webbundle)

You can also install the war directly from a location using the “classic” bundle:install command. As a war is not a “regular” bundle, we need to use the webbundle protocol to specify the artifact is actually a war.

First, we install the war feature which provides the webbundle protocol:

karaf@root()> feature:install war

Then, we can directly install a war from any location, for instance:

karaf@root()> bundle:install -s webbundle:mvn:org.apache.karaf.examples/karaf-war-example-webapp/4.3.0-SNAPSHOT/war?Web-ContextPath=example

You can see the war deployed using web:list command:

karaf@root()> web:list
ID  │ State       │ Web-State   │ Level │ Web-ContextPath │ Name
────┼─────────────┼─────────────┼───────┼─────────────────┼──────────────────────────────────────────────────────────────────────────────
102 │ Active      │ Deployed    │ 80    │ /example        │ mvn_org.apache.karaf.examples_karaf-war-example-webapp_4.3.0-SNAPSHOT_war (0)

We specify the context path on the URL. You can then point your browser to [http://localhost:8181/example].

Feature

You can use the webbundle protocol on URL directly in a features repository.

It's illustrated in the karaf-war-example-features features repository.

Then, you simply have to add this features repository and directly install the karaf-war-example feature containing the war. This feature automatically installs the war feature, all in a row.

First, you add the features repository:

karaf@root()> feature:repo-add mvn:org.apache.karaf.examples/karaf-war-example-features/4.3.0-SNAPSHOT/xml
Adding feature url mvn:org.apache.karaf.examples/karaf-war-example-features/4.3.0-SNAPSHOT/xml

Then, you can install the karaf-war-example:

karaf@root()> feature:install karaf-war-example

You can see the war deployed using web:list command:

karaf@root()> web:list
ID  │ State       │ Web-State   │ Level │ Web-ContextPath │ Name
────┼─────────────┼─────────────┼───────┼─────────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
102 │ Active      │ Deployed    │ 80    │ /example        │ file__home_jbonofre_.m2_repository_org_apache_karaf_examples_karaf-war-example-webapp_4.3.0-SNAPSHOT_karaf-war-example-webapp-4.3.0-SNAPSHOT.war (0)

You can then point your browser to [http://localhost:8181/example].