OpenLiberty notes¶

Create OpenLiberty webapp¶

From starting repo¶

git clone https://github.com/openliberty/guide-getting-started.git
# or
git clone https://github.com/OpenLiberty/sample-getting-started.git
cd sample-getting-started
mvn liberty:dev

maven commands¶

# dev mode: The Open Liberty server automatically reloads the configuration without restarting
mvn liberty:dev
# dev mode with docker
#builds a Docker image, mounts the required directories, binds the required ports, and then runs the application inside of a container
mvn liberty:devc 
# or control the start, stop...
mvn liberty:run
mvn liberty:start
mvn liberty:stop

These messages are also logged to the target/liberty/wlp/usr/servers/defaultServer/logs/console.log. You can find the error logs in the ffdc directory and the tracing logs in the trace.log file.

To set properties, they can be set in the server.xml

  <variable name="app.inMaintenance" value="false"/>

Build . test . package¶

mvn package
# will create a war file with the <artifactId> name

Instead of creating a server package, you can generate a runnable JAR file that contains the application along with a server runtime. As a result, the generated JAR file is only about 50 MB.

mvn liberty:package -Dinclude=runnable
# execute
java -jar yourapp.jar

Features¶

mpHealth-4.0" health Check and Readiness classes

CDI¶

When bean must be persistent between all of the clients, which means multiple clients need to share the same instance. Simply add the @ApplicationScoped annotation onto the class.

With the @RequestScoped annotation, the bean is instantiated when the request is received and destroyed when a response is sent back to the client. A request scope is short-lived.

The @Inject annotation indicates a dependency injection

OpenLiberty Operator¶

OpenLiberty Operator helps to deploy and manage applications running on Open Liberty into kubernetes or OpenShift clusters.

To build a openliberty app docker image follow guidelines here.

Install it using the Operator Hub. Once installed the following commands

Open liberty links¶

Debug Openliberty app¶

Start mvn liberty:debug, the console should display the port number, it listens to (7777). Then in Eclipse define a debud configuration for a remote java application, use localhost and the matching port number. Any breakpoint in the code should be reachable.

For VS code: