Inherit ENTRYPOINT and CMD from base image for WAR projects (#1071)

* Support WARs : inherit entrypoint from base images (Jetty / Tomcat / ? / ... )

* Improves UX

* Inherits entrypoint when entrypoint is null

* Some refactor

* Refactor

* Fixes rebasing + changes program arguments

* Fixes review comments

* Fixes rebase problems
Removes "CMD []" when entrypoint is present in Dockerfile
Changes a TODO description

jib-core/src/main/java/com/google/cloud/tools/jib/api/JibContainerBuilder.java

@@ -162,8 +162,10 @@ public JibContainerBuilder addLayer(LayerConfiguration layerConfiguration) {
  * @param entrypoint a list of the entrypoint command
  * @return this
  */
- public JibContainerBuilder setEntrypoint(List<String> entrypoint) {
- this.entrypoint = ImmutableList.copyOf(entrypoint);
+ public JibContainerBuilder setEntrypoint(@Nullable List<String> entrypoint) {
+ if (entrypoint != null) {
+ this.entrypoint = ImmutableList.copyOf(entrypoint);
+ }
  return this;
  }
 
@@ -194,8 +196,10 @@ public JibContainerBuilder setEntrypoint(String... entrypoint) {
  * @param programArguments a list of program argument tokens
  * @return this
  */
- public JibContainerBuilder setProgramArguments(List<String> programArguments) {
- this.programArguments = ImmutableList.copyOf(programArguments);
+ public JibContainerBuilder setProgramArguments(@Nullable List<String> programArguments) {
+ if (programArguments != null) {
+ this.programArguments = ImmutableList.copyOf(programArguments);
+ }
  return this;
  }
 

jib-core/src/main/java/com/google/cloud/tools/jib/builder/BuildSteps.java

@@ -158,12 +158,16 @@ public DescriptorDigest run() throws InterruptedException, ExecutionException {
 
  if (buildConfiguration.getContainerConfiguration() != null) {
  buildConfiguration.getEventDispatcher().dispatch(LogEvent.lifecycle(""));
- buildConfiguration
- .getEventDispatcher()
- .dispatch(
- LogEvent.lifecycle(
- "Container entrypoint set to "
- + buildConfiguration.getContainerConfiguration().getEntrypoint()));
+ // TODO refactor code to also log ENTRYPOINT and CMD when inheriting them in this code,
+ // instead of logging them elsewhere.
+ if (buildConfiguration.getContainerConfiguration().getEntrypoint() != null) {
+ buildConfiguration
+ .getEventDispatcher()
+ .dispatch(
+ LogEvent.lifecycle(
+ "Container entrypoint set to "
+ + buildConfiguration.getContainerConfiguration().getEntrypoint()));
+ }
  }
 
  return imageDigest;

jib-core/src/main/java/com/google/cloud/tools/jib/builder/steps/BuildImageStep.java

@@ -25,6 +25,7 @@
 import com.google.cloud.tools.jib.cache.CacheEntry;
 import com.google.cloud.tools.jib.configuration.BuildConfiguration;
 import com.google.cloud.tools.jib.configuration.ContainerConfiguration;
+import com.google.cloud.tools.jib.event.events.LogEvent;
 import com.google.cloud.tools.jib.image.DescriptorDigest;
 import com.google.cloud.tools.jib.image.Image;
 import com.google.cloud.tools.jib.image.Layer;
@@ -40,6 +41,7 @@
 import java.util.List;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
+import javax.annotation.Nullable;
 
 /** Builds a model {@link Image}. */
 class BuildImageStep
@@ -176,8 +178,9 @@ private Image<Layer> afterCacheEntrySteps()
  imageBuilder.addEnvironment(containerConfiguration.getEnvironmentMap());
  imageBuilder.setCreated(containerConfiguration.getCreationTime());
  imageBuilder.setUser(containerConfiguration.getUser());
- imageBuilder.setEntrypoint(containerConfiguration.getEntrypoint());
- imageBuilder.setProgramArguments(containerConfiguration.getProgramArguments());
+ imageBuilder.setEntrypoint(computeEntrypoint(baseImage, containerConfiguration));
+ imageBuilder.setProgramArguments(
+ computeProgramArguments(baseImage, containerConfiguration));
  imageBuilder.setExposedPorts(containerConfiguration.getExposedPorts());
  imageBuilder.addLabels(containerConfiguration.getLabels());
  }
@@ -186,4 +189,59 @@ private Image<Layer> afterCacheEntrySteps()
  return imageBuilder.build();
  }
  }
+
+ /**
+ * Computes the image entrypoint. If {@link ContainerConfiguration#getEntrypoint()} is null, the
+ * entrypoint is inherited from the base image. Otherwise {@link
+ * ContainerConfiguration#getEntrypoint()} is returned.
+ *
+ * @param baseImage the base image
+ * @param containerConfiguration the container configuration
+ * @return the container entrypoint
+ */
+ @Nullable
+ private ImmutableList<String> computeEntrypoint(
+ Image<Layer> baseImage, ContainerConfiguration containerConfiguration) {
+ if (baseImage.getEntrypoint() == null || containerConfiguration.getEntrypoint() != null) {
+ return containerConfiguration.getEntrypoint();
+ }
+
+ buildConfiguration
+ .getEventDispatcher()
+ .dispatch(
+ LogEvent.lifecycle(
+ "Container entrypoint set to "
+ + baseImage.getEntrypoint()
+ + " (inherited from base image)"));
+ return baseImage.getEntrypoint();
+ }
+
+ /**
+ * Computes the image program arguments. If {@link ContainerConfiguration#getEntrypoint()} and
+ * {@link ContainerConfiguration#getProgramArguments()} are null, the program arguments are
+ * inherited from the base image. Otherwise {@link ContainerConfiguration#getProgramArguments()}
+ * is returned.
+ *
+ * @param baseImage the base image
+ * @param containerConfiguration the container configuration
+ * @return the container program arguments
+ */
+ @Nullable
+ private ImmutableList<String> computeProgramArguments(
+ Image<Layer> baseImage, ContainerConfiguration containerConfiguration) {
+ if (baseImage.getProgramArguments() == null
+ || containerConfiguration.getEntrypoint() != null
+ || containerConfiguration.getProgramArguments() != null) {
+ return containerConfiguration.getProgramArguments();
+ }
+
+ buildConfiguration
+ .getEventDispatcher()
+ .dispatch(
+ LogEvent.lifecycle(
+ "Container program arguments set to "
+ + baseImage.getProgramArguments()
+ + " (inherited from base image)"));
+ return baseImage.getProgramArguments();
+ }
 }

jib-core/src/main/java/com/google/cloud/tools/jib/frontend/JavaDockerContextGenerator.java

@@ -89,7 +89,6 @@ private CopyDirective(
  * @param listBuilder the {@link ImmutableList.Builder} to add to
  * @param layerEntries the layer entries
  * @param directoryInContext the directory in the context to put the source files for the layer
- * @param extractionPath the extraction path to extract the directory to
  */
  private static void addIfNotEmpty(
  ImmutableList.Builder<CopyDirective> listBuilder,
@@ -132,9 +131,9 @@ private static String mapToDockerfileString(Map<String, String> map, String comm
  private final ImmutableList<CopyDirective> copyDirectives;
 
  @Nullable private String baseImage;
- private List<String> entrypoint = Collections.emptyList();
+ @Nullable private List<String> entrypoint = Collections.emptyList();
+ @Nullable private List<String> programArguments = Collections.emptyList();
  @Nullable private String user;
- private List<String> programArguments = Collections.emptyList();
  private Map<String, String> environment = Collections.emptyMap();
  private List<String> exposedPorts = Collections.emptyList();
  private Map<String, String> labels = Collections.emptyMap();
@@ -187,7 +186,7 @@ public JavaDockerContextGenerator setBaseImage(String baseImage) {
  * @param entrypoint the entrypoint
  * @return this
  */
- public JavaDockerContextGenerator setEntrypoint(List<String> entrypoint) {
+ public JavaDockerContextGenerator setEntrypoint(@Nullable List<String> entrypoint) {
  this.entrypoint = entrypoint;
  return this;
  }
@@ -209,7 +208,7 @@ public JavaDockerContextGenerator setUser(@Nullable String user) {
  * @param programArguments the list of arguments to append to {@code ENTRYPOINT}
  * @return this
  */
- public JavaDockerContextGenerator setProgramArguments(List<String> programArguments) {
+ public JavaDockerContextGenerator setProgramArguments(@Nullable List<String> programArguments) {
  this.programArguments = programArguments;
  return this;
  }
@@ -339,11 +338,12 @@ String makeDockerfile() throws JsonProcessingException {
 
  dockerfile.append(mapToDockerfileString(environment, "ENV"));
  dockerfile.append(mapToDockerfileString(labels, "LABEL"));
- dockerfile
- .append("\nENTRYPOINT ")
- .append(objectMapper.writeValueAsString(entrypoint))
- .append("\nCMD ")
- .append(objectMapper.writeValueAsString(programArguments));
+ if (entrypoint != null) {
+ dockerfile.append("\nENTRYPOINT ").append(objectMapper.writeValueAsString(entrypoint));
+ }
+ if (programArguments != null) {
+ dockerfile.append("\nCMD ").append(objectMapper.writeValueAsString(programArguments));
+ }
  if (user != null) {
  dockerfile.append("\nUSER ").append(user);
  }

jib-core/src/main/java/com/google/cloud/tools/jib/frontend/JavaEntrypointConstructor.java

@@ -43,18 +43,6 @@ public static List<String> makeDefaultEntrypoint(
  mainClass);
  }
 
- /**
- * Constructs the container entrypoint for the gcr.io/distroless/jetty base image.
- *
- * @return ["java", "-jar", "/jetty/start.jar"]
- * @see <a href="https:/GoogleContainerTools/distroless/blob/master/java/jetty/BUILD">
- * https:/GoogleContainerTools/distroless/blob/master/java/jetty/BUILD</a>
- */
- // TODO: inherit CMD and ENTRYPOINT from the base image and remove this.
- public static List<String> makeDistrolessJettyEntrypoint() {
- return Arrays.asList("java", "-jar", "/jetty/start.jar");
- }
-
  /**
  * Constructs the container entrypoint.
  *

jib-core/src/test/java/com/google/cloud/tools/jib/builder/steps/BuildImageStepTest.java

@@ -116,6 +116,8 @@ public Blob getLayerBlob() {
  .addEnvironment(ImmutableMap.of("BASE_ENV", "BASE_ENV_VALUE"))
  .addLabel("base.label", "base.label.value")
  .setWorkingDirectory("/base/working/directory")
+ .setEntrypoint(ImmutableList.of("baseImageEntrypoint"))
+ .setProgramArguments(ImmutableList.of("catalina.sh", "run"))
  .addHistory(nonEmptyLayerHistory)
  .addHistory(emptyLayerHistory)
  .addHistory(emptyLayerHistory)
@@ -184,6 +186,74 @@ public void test_propagateBaseImageConfiguration()
  Assert.assertEquals(image.getHistory().get(0), nonEmptyLayerHistory);
  Assert.assertEquals(image.getHistory().get(1), emptyLayerHistory);
  Assert.assertEquals(image.getHistory().get(2), emptyLayerHistory);
+ Assert.assertEquals(ImmutableList.of(), image.getEntrypoint());
+ Assert.assertEquals(ImmutableList.of(), image.getProgramArguments());
+ }
+
+ @Test
+ public void test_inheritedEntrypoint() throws ExecutionException, InterruptedException {
+ Mockito.when(mockContainerConfiguration.getEntrypoint()).thenReturn(null);
+ Mockito.when(mockContainerConfiguration.getProgramArguments())
+ .thenReturn(ImmutableList.of("test"));
+
+ BuildImageStep buildImageStep =
+ new BuildImageStep(
+ MoreExecutors.listeningDecorator(Executors.newSingleThreadExecutor()),
+ mockBuildConfiguration,
+ mockPullBaseImageStep,
+ mockPullAndCacheBaseImageLayersStep,
+ ImmutableList.of(
+ mockBuildAndCacheApplicationLayerStep,
+ mockBuildAndCacheApplicationLayerStep,
+ mockBuildAndCacheApplicationLayerStep));
+ Image<Layer> image = buildImageStep.getFuture().get().getFuture().get();
+
+ Assert.assertEquals(ImmutableList.of("baseImageEntrypoint"), image.getEntrypoint());
+ Assert.assertEquals(ImmutableList.of("test"), image.getProgramArguments());
+ }
+
+ @Test
+ public void test_inheritedEntrypointAndProgramArguments()
+ throws ExecutionException, InterruptedException {
+ Mockito.when(mockContainerConfiguration.getEntrypoint()).thenReturn(null);
+ Mockito.when(mockContainerConfiguration.getProgramArguments()).thenReturn(null);
+
+ BuildImageStep buildImageStep =
+ new BuildImageStep(
+ MoreExecutors.listeningDecorator(Executors.newSingleThreadExecutor()),
+ mockBuildConfiguration,
+ mockPullBaseImageStep,
+ mockPullAndCacheBaseImageLayersStep,
+ ImmutableList.of(
+ mockBuildAndCacheApplicationLayerStep,
+ mockBuildAndCacheApplicationLayerStep,
+ mockBuildAndCacheApplicationLayerStep));
+ Image<Layer> image = buildImageStep.getFuture().get().getFuture().get();
+
+ Assert.assertEquals(ImmutableList.of("baseImageEntrypoint"), image.getEntrypoint());
+ Assert.assertEquals(ImmutableList.of("catalina.sh", "run"), image.getProgramArguments());
+ }
+
+ @Test
+ public void test_notInheritedProgramArguments() throws ExecutionException, InterruptedException {
+ Mockito.when(mockContainerConfiguration.getEntrypoint())
+ .thenReturn(ImmutableList.of("myEntrypoint"));
+ Mockito.when(mockContainerConfiguration.getProgramArguments()).thenReturn(null);
+
+ BuildImageStep buildImageStep =
+ new BuildImageStep(
+ MoreExecutors.listeningDecorator(Executors.newSingleThreadExecutor()),
+ mockBuildConfiguration,
+ mockPullBaseImageStep,
+ mockPullAndCacheBaseImageLayersStep,
+ ImmutableList.of(
+ mockBuildAndCacheApplicationLayerStep,
+ mockBuildAndCacheApplicationLayerStep,
+ mockBuildAndCacheApplicationLayerStep));
+ Image<Layer> image = buildImageStep.getFuture().get().getFuture().get();
+
+ Assert.assertEquals(ImmutableList.of("myEntrypoint"), image.getEntrypoint());
+ Assert.assertNull(image.getProgramArguments());
  }
 
  @Test

jib-core/src/test/java/com/google/cloud/tools/jib/frontend/JavaEntrypointConstructorTest.java

@@ -73,10 +73,4 @@ public void testMakeDefaultEntrypoint_classpathStringWithNonDefaultAppRoot() {
  AbsoluteUnixPath.get("/my/app"), Collections.emptyList(), "Main");
  Assert.assertEquals("/my/app/resources:/my/app/classes:/my/app/libs/*", entrypoint.get(2));
  }
-
- @Test
- public void testMakeDistrolessJettyEntrypoint() {
- List<String> expected = Arrays.asList("java", "-jar", "/jetty/start.jar");
- Assert.assertEquals(expected, JavaEntrypointConstructor.makeDistrolessJettyEntrypoint());
- }
 }

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

@@ -38,7 +38,7 @@ public class ContainerParameters {
  private Map<String, String> environment = Collections.emptyMap();
  private List<String> entrypoint = Collections.emptyList();
  @Nullable private String mainClass;
- private List<String> args = Collections.emptyList();
+ @Nullable private List<String> args;
  private ImageFormat format = ImageFormat.Docker;
  private List<String> ports = Collections.emptyList();
  private Map<String, String> labels = Collections.emptyMap();
@@ -115,6 +115,7 @@ public void setMainClass(String mainClass) {
  }
 
  @Input
+ @Nullable
  @Optional
  public List<String> getArgs() {
  if (System.getProperty(PropertyNames.CONTAINER_ARGS) != null) {

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

@@ -42,6 +42,7 @@
 import java.util.List;
 import java.util.Optional;
 import java.util.logging.Level;
+import javax.annotation.Nullable;
 import org.gradle.api.GradleException;
 import org.gradle.api.logging.Logger;
 import org.gradle.internal.logging.events.LogEvent;
@@ -139,6 +140,7 @@ static PluginConfigurationProcessor processCommonConfiguration(
  .setLayers(projectProperties.getJavaLayerConfigurations().getLayerConfigurations())
  .setEntrypoint(entrypoint)
  .setEnvironment(jibExtension.getContainer().getEnvironment())
+ .setProgramArguments(jibExtension.getContainer().getArgs())
  .setExposedPorts(ExposedPortsParser.parse(jibExtension.getContainer().getPorts()))
  .setProgramArguments(jibExtension.getContainer().getArgs())
  .setLabels(jibExtension.getContainer().getLabels())
@@ -174,7 +176,7 @@ static void configureContainerizer(
  *
  * <ol>
  * <li>the user specified one, if set
- * <li>for a WAR project, the Jetty default one
+ * <li>for a WAR project, null (it must be inherited from base image)
  * <li>for a non-WAR project, by resolving the main class
  * </ol>
  *
@@ -183,6 +185,7 @@ static void configureContainerizer(
  * @param projectProperties used for providing additional information
  * @return the entrypoint
  */
+ @Nullable
  static List<String> computeEntrypoint(
  Logger logger, JibExtension jibExtension, GradleProjectProperties projectProperties) {
  ContainerParameters parameters = jibExtension.getContainer();
@@ -194,7 +197,7 @@ static List<String> computeEntrypoint(
  }
 
  if (projectProperties.isWarProject()) {
- return JavaEntrypointConstructor.makeDistrolessJettyEntrypoint();
+ return null;
  }
 
  String mainClass = projectProperties.getMainClass(jibExtension);