Support lazy configuration for jvmFlags property of ContainerParameters

Fixes GoogleContainerTools#3936.

Author: erdi

jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/ContainerParameters.java

@@ -26,6 +26,7 @@
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 import org.gradle.api.model.ObjectFactory;
+import org.gradle.api.provider.ListProperty;
 import org.gradle.api.provider.MapProperty;
 import org.gradle.api.provider.Property;
 import org.gradle.api.tasks.Input;
@@ -37,7 +38,7 @@
  */
 public class ContainerParameters {
 
-  private List<String> jvmFlags = Collections.emptyList();
+  private final ListProperty<String> jvmFlags;
   private Map<String, String> environment = Collections.emptyMap();
   @Nullable private List<String> entrypoint;
   private List<String> extraClasspath = Collections.emptyList();
@@ -60,6 +61,7 @@ public ContainerParameters(ObjectFactory objectFactory) {
     filesModificationTime = objectFactory.property(String.class).convention("EPOCH_PLUS_SECOND");
     creationTime = objectFactory.property(String.class).convention("EPOCH");
     mainClass = objectFactory.property(String.class);
+    jvmFlags = objectFactory.listProperty(String.class).convention(Collections.emptyList());
   }
 
   @Input
@@ -83,18 +85,18 @@ public void setEntrypoint(String entrypoint) {
 
   @Input
   @Optional
-  public List<String> getJvmFlags() {
-    if (System.getProperty(PropertyNames.CONTAINER_JVM_FLAGS) != null) {
-      return ConfigurationPropertyValidator.parseListProperty(
-          System.getProperty(PropertyNames.CONTAINER_JVM_FLAGS));
+  public ListProperty<String> getJvmFlags() {
+    String jvmFlagsSystemProperty = System.getProperty(PropertyNames.CONTAINER_JVM_FLAGS);
+    if (jvmFlagsSystemProperty != null) {
+      List<String> parsedJvmFlags =
+          ConfigurationPropertyValidator.parseListProperty(jvmFlagsSystemProperty);
+      if (!parsedJvmFlags.equals(jvmFlags.get())) {
+        jvmFlags.set(parsedJvmFlags);
+      }
     }
     return jvmFlags;
   }
 
-  public void setJvmFlags(List<String> jvmFlags) {
-    this.jvmFlags = jvmFlags;
-  }
-
   @Input
   @Optional
   public Map<String, String> getEnvironment() {

jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/GradleRawConfiguration.java

@@ -98,7 +98,7 @@ public Optional<String> getMainClass() {
 
   @Override
   public List<String> getJvmFlags() {
-    return jibExtension.getContainer().getJvmFlags();
+    return jibExtension.getContainer().getJvmFlags().get();
   }
 
   @Override

jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/GradleRawConfigurationTest.java

@@ -25,6 +25,7 @@
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Optional;
+import org.gradle.api.provider.ListProperty;
 import org.gradle.api.provider.MapProperty;
 import org.gradle.api.provider.Property;
 import org.junit.Assert;
@@ -40,6 +41,7 @@ public class GradleRawConfigurationTest {
 
   @Mock private MapProperty<String, String> labels;
   @Mock private Property<String> mainClass;
+  @Mock private ListProperty<String> jvmFlags;
 
   @Test
   public void testGetters() {
@@ -88,7 +90,8 @@ public void testGetters() {
     Mockito.when(containerParameters.getEntrypoint()).thenReturn(Arrays.asList("java", "Main"));
     Mockito.when(containerParameters.getEnvironment())
         .thenReturn(new HashMap<>(ImmutableMap.of("currency", "dollar")));
-    Mockito.when(containerParameters.getJvmFlags()).thenReturn(Arrays.asList("-cp", "."));
+    Mockito.when(jvmFlags.get()).thenReturn(Arrays.asList("-cp", "."));
+    Mockito.when(containerParameters.getJvmFlags()).thenReturn(jvmFlags);
     Mockito.when(labels.get()).thenReturn(Collections.singletonMap("unit", "cm"));
     Mockito.when(containerParameters.getLabels()).thenReturn(labels);
     Mockito.when(mainClass.getOrNull()).thenReturn("com.example.Main");

jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/JibExtensionTest.java

@@ -175,7 +175,7 @@ public void testToTags_containsEmptyTag() {
 
   @Test
   public void testContainer() {
-    assertThat(testJibExtension.getContainer().getJvmFlags()).isEmpty();
+    assertThat(testJibExtension.getContainer().getJvmFlags().get()).isEmpty();
     assertThat(testJibExtension.getContainer().getEnvironment()).isEmpty();
     assertThat(testJibExtension.getContainer().getExtraClasspath()).isEmpty();
     assertThat(testJibExtension.getContainer().getExpandClasspathDependencies()).isFalse();
@@ -191,7 +191,7 @@ public void testContainer() {
 
     testJibExtension.container(
         container -> {
-          container.setJvmFlags(Arrays.asList("jvmFlag1", "jvmFlag2"));
+          container.getJvmFlags().set(Arrays.asList("jvmFlag1", "jvmFlag2"));
           container.setEnvironment(ImmutableMap.of("var1", "value1", "var2", "value2"));
           container.setEntrypoint(Arrays.asList("foo", "bar", "baz"));
           container.setExtraClasspath(Arrays.asList("/d1", "/d2", "/d3"));
@@ -206,7 +206,7 @@ public void testContainer() {
         });
     ContainerParameters container = testJibExtension.getContainer();
     assertThat(container.getEntrypoint()).containsExactly("foo", "bar", "baz").inOrder();
-    assertThat(container.getJvmFlags()).containsExactly("jvmFlag1", "jvmFlag2").inOrder();
+    assertThat(container.getJvmFlags().get()).containsExactly("jvmFlag1", "jvmFlag2").inOrder();
     assertThat(container.getEnvironment())
         .containsExactly("var1", "value1", "var2", "value2")
         .inOrder();
@@ -477,7 +477,7 @@ public void testProperties() {
     System.setProperty("jib.container.format", "OCI");
     assertThat(testJibExtension.getContainer().getFormat()).isSameInstanceAs(ImageFormat.OCI);
     System.setProperty("jib.container.jvmFlags", "flag1,flag2,flag3");
-    assertThat(testJibExtension.getContainer().getJvmFlags())
+    assertThat(testJibExtension.getContainer().getJvmFlags().get())
         .containsExactly("flag1", "flag2", "flag3")
         .inOrder();
     System.setProperty("jib.container.labels", "label1=val1,label2=val2");

jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/JibPluginTest.java

@@ -413,6 +413,12 @@ public void testLazyEvalForMainClass() {
     assertThat(showLabels.getOutput()).contains("mainClass value updated");
   }
 
+  @Test
+  public void testLazyEvalForJvmFlags() {
+    BuildResult showLabels = testProject.build("showJvmFlags");
+    assertThat(showLabels.getOutput()).contains("jvmFlags value [updated]");
+  }
+
   private Project createProject(String... plugins) {
     Project project =
         ProjectBuilder.builder().withProjectDir(testProjectRoot.getRoot()).withName("root").build();

jib-gradle-plugin/src/test/resources/gradle/projects/lazy-evaluation/build.gradle

@@ -40,6 +40,7 @@ jib {
         creationTime = project.provider { project.ext.jibCreationTime }
         filesModificationTime = project.provider { project.ext.jibFilesModificationTime }
         mainClass = project.provider { project.ext.value }
+        jvmFlags = project.provider { [project.ext.value] }
     }
     extraDirectories {
         paths = project.provider { ['src/main/' + project.ext.value + '-custom-extra-dir'] }
@@ -70,3 +71,8 @@ tasks.register('showMainClass') {
     String prop = project.extensions.jib.container.mainClass.get()
     println('mainClass value ' + prop)
 }
+
+tasks.register('showJvmFlags') {
+    List<String> prop = project.extensions.jib.container.jvmFlags.get()
+    println('jvmFlags value ' + prop)
+}