title: JKube maven plugin can't find jar file when building docker image using mvn k8s:build
body: <p>I'm trying to use <a href="https://www.eclipse.org/jkube/" rel="nofollow noreferrer">JKube</a> for building and deploying APIs to my K8S cluster but when I do <code>mvn k8s:build</code> I'm getting this error :</p>
  <pre><code>[INFO] --- kubernetes-maven-plugin:1.1.1:build (default-cli) @ trips-api ---
  [INFO] k8s: Running in Kubernetes mode
  [INFO] k8s: Building Docker image in Kubernetes mode
  [INFO] k8s: [carpooling/trips-api:latest]: Created docker-build.tar in 2 seconds 
  [ERROR] k8s: Failed to execute the build [Error while trying to build the image: Unable to build image [carpooling/trips-api:latest] : &quot;COPY failed: no source files were specified&quot; ]
  </code></pre>
  <p>This is the content of my <code>Dockerfile</code>:</p>
  <pre><code>FROM adoptopenjdk/openjdk11:latest
  VOLUME /tmp
  COPY target/*.jar app.jar
  ENTRYPOINT [&quot;java&quot;,&quot;-jar&quot;,&quot;/app.jar&quot;]
  </code></pre>
  <p>NB: I'm ensuring that under my target/ directory I have the right jar file.</p>
  <p>Does anyone have an idea about why I'm getting this error ?</p>