How can I configure the port a Quarkus application runs on?

The Quarkus configuration property to be used is quarkus.http.port (the default value is 8080). If this property is set in application.properties then that value will be used.

The property can also be overridden at runtime as follows:

When running a Quarkus application in JVM mode you can set the port using the quarkus.http.port System property. For example:

java -Dquarkus.http.port=8081 -jar example-runner.java

The same property applies to GraalVM Native Mode images. For example:

./example-runner -Dquarkus.http.port=8081

To complement geoand’s answer, you can use the same property for mvn quarkus:dev. Unfortunately you cannot directly set it in a profile in ~/.m2/settings.xml to avoid the need to type it each time (for example because Microk8s binds 8080), but you can set it via jvm.args:

<profiles>
    <profile>
        <id>microk8s-quarkus-dev</id>
        <activation>
            <activeByDefault>true</activeByDefault>
        </activation>
        <properties>
            <jvm.args>-Dquarkus.http.port=8090</jvm.args>
        </properties>
    </profile>
</profiles>

Alternately, you could configure this in project sources:

echo '%dev.quarkus.http.port=8090' >> src/main/resources/application.properties

though this would not be shared across projects, and might be unwanted by other developers of the same project.