Warn when the 'component' artifact is embedded in the bundle.

- Embedding it may cause resource leaks in the container runtime
  because the framework will not be able to identify user
  components that extend AbstractComponent.

1 files changed, 18 insertions, 0 deletions

diff --git a/bundle-plugin/src/main/java/com/yahoo/container/plugin/mojo/GenerateOsgiManifestMojo.java b/bundle-plugin/src/main/java/com/yahoo/container/plugin/mojo/GenerateOsgiManifestMojo.java
index 3020184fd35..864c8d6fe9c 100644
--- a/bundle-plugin/src/main/java/com/yahoo/container/plugin/mojo/GenerateOsgiManifestMojo.java
+++ b/bundle-plugin/src/main/java/com/yahoo/container/plugin/mojo/GenerateOsgiManifestMojo.java
@@ -59,6 +59,7 @@ public class GenerateOsgiManifestMojo extends AbstractGenerateOsgiManifestMojo {
         try {
             Artifacts.ArtifactSet artifactSet = Artifacts.getArtifacts(project);
             warnOnUnsupportedArtifacts(artifactSet.getNonJarArtifacts());
+            warnIfInternalContainerArtifactsAreIncluded(artifactSet.getJarArtifactsToInclude());
 
             List<Export> exportedPackagesFromProvidedJars = exportedPackagesAggregated(
                     artifactSet.getJarArtifactsProvided().stream().map(Artifact::getFile).collect(Collectors.toList()));
@@ -180,6 +181,23 @@ public class GenerateOsgiManifestMojo extends AbstractGenerateOsgiManifestMojo {
                         artifact.getId(), artifact.getType())));
     }
 
+    // TODO: fail the build by throwing a MojoExecutionException
+    private void warnIfInternalContainerArtifactsAreIncluded(Collection<Artifact> includedArtifacts) throws MojoExecutionException {
+        /* In most cases it's sufficient to test for 'component', as it's the lowest level container artifact,
+         * Embedding container artifacts will cause class loading issues at runtime, because the classes will
+         * not be equal to those seen by the framework (e.g. AbstractComponent).
+         */
+        if (includedArtifacts.stream().anyMatch(this::isJdiscComponentArtifact)) {
+            getLog().warn("This project includes the 'com.yahoo.vespa:component' artifact in compile scope." +
+                                  " It must be set to scope 'provided' to avoid resource leaks in your application at runtime." +
+                                  " The build will fail on a future Vespa version unless this is fixed.");
+        }
+    }
+
+    private boolean isJdiscComponentArtifact(Artifact a) {
+        return a.getArtifactId().equals("component") && a.getGroupId().equals("com.yahoo.vespa");
+    }
+
     private PackageTally getProjectClassesTally() {
         File outputDirectory = new File(project.getBuild().getOutputDirectory());