CAMEL-23601: camel-jbang - export layered Docker packaging for Main and Spring Boot

docs/user-manual/modules/ROOT/pages/camel-4x-upgrade-guide-4_21.adoc

@@ -111,25 +111,25 @@ auto-disables `contentCache` on resource-based components (such as `xslt`) whose
 the route. Set `camel.component.<name>.contentCache=true` (or pass `?contentCache=true` on the
 URI) to opt back in to caching during dev mode.
 
-==== Unified `--packaging` option for `camel export`
+==== Container-optimized layered Docker packaging for `camel export`
 
-A new `--packaging` option has been added to `camel export` that works across all three runtimes
-(Camel Main, Spring Boot, and Quarkus). It replaces the Quarkus-specific `--quarkus-package-type`
-option, which is now deprecated.
+The `camel export` command now generates Dockerfiles optimized for container image layer caching
+across all three runtimes. Previously, Camel Main and Spring Boot exports produced a single-layer
+fat JAR Dockerfile; now each runtime uses a layered approach where dependencies (stable) and
+application code (volatile) are in separate Docker layers.
 
-Accepted values:
-
-- `layered` or `fast-jar` — container-optimized packaging with separate dependency layers (default)
-- `fat-jar` or `uber-jar` — single executable JAR
-
-The default is `layered`, which produces Dockerfiles optimized for container image layer caching.
 Each runtime implements layered packaging using its native mechanism:
 
-- **Camel Main**: thin JAR with dependencies in a `lib/` folder
-- **Spring Boot**: multi-stage Dockerfile using Spring Boot's built-in layer extraction
-- **Quarkus**: fast-jar packaging (unchanged from the previous `--quarkus-package-type=fast-jar` default)
+- **Camel Main**: the generated POM now includes `maven-jar-plugin` (with classpath manifest) and
+  `maven-dependency-plugin:copy-dependencies`. The Dockerfile copies `target/lib/` first (cached
+  dependency layer), then the thin `.original` JAR (small application layer).
+- **Spring Boot**: a multi-stage Dockerfile using Spring Boot's `jarmode=tools extract --layers`
+  to split the fat JAR into 4 Docker layers (dependencies, spring-boot-loader,
+  snapshot-dependencies, application).
+- **Quarkus**: unchanged — already uses fast-jar packaging with a 4-layer Dockerfile.
 
-The deprecated `--quarkus-package-type` option continues to work for backward compatibility.
+The Quarkus-specific `--quarkus-package-type` option is now deprecated and hidden from help output.
+Quarkus exports always use fast-jar (layered) packaging.
 
 ==== Improved default `--quarkus-version`
 

docs/user-manual/modules/ROOT/pages/jbang-commands/camel-jbang-dependency-copy.adoc

@@ -60,7 +60,6 @@ camel dependency copy [options]
 | `--quarkus-artifact-id` _(deprecated)_ | Deprecated. This value is not used anymore. It is kept only for backwards compatibility and will be removed in Camel 5.x. Camel commands may use either 'quarkus-bom' or 'quarkus-camel-bom' artifactIds depending on the context. | quarkus-bom | String
 | `--quarkus-ext-registry` | The base URI of Quarkus Extension Registry. The default is {@value RuntimeType#QUARKUS_EXTENSION_REGISTRY_BASE_URL} unless camel.jbang.quarkus.platform.url system property is set (the /client/platforms suffix is removed if present). |  | String
 | `--quarkus-group-id` | groupId of Quarkus Platform BOM; honored only if --quarkus-version is set | io.quarkus.platform | String
-| `--quarkus-package-type` | Quarkus package type (uber-jar or fast-jar) | fast-jar | String
 | `--quarkus-version` | version of Quarkus Platform BOM; the default value is looked up in Quarkus Extension Registry |  | String
 | `--quiet` | Will be quiet, only print when error occurs | false | boolean
 | `--repo,--repos` | Additional maven repositories for download on-demand (Use commas to separate multiple repositories) |  | String

docs/user-manual/modules/ROOT/pages/jbang-commands/camel-jbang-dependency-list.adoc

@@ -59,7 +59,6 @@ camel dependency list [options]
 | `--quarkus-artifact-id` _(deprecated)_ | Deprecated. This value is not used anymore. It is kept only for backwards compatibility and will be removed in Camel 5.x. Camel commands may use either 'quarkus-bom' or 'quarkus-camel-bom' artifactIds depending on the context. | quarkus-bom | String
 | `--quarkus-ext-registry` | The base URI of Quarkus Extension Registry. The default is {@value RuntimeType#QUARKUS_EXTENSION_REGISTRY_BASE_URL} unless camel.jbang.quarkus.platform.url system property is set (the /client/platforms suffix is removed if present). |  | String
 | `--quarkus-group-id` | groupId of Quarkus Platform BOM; honored only if --quarkus-version is set | io.quarkus.platform | String
-| `--quarkus-package-type` | Quarkus package type (uber-jar or fast-jar) | fast-jar | String
 | `--quarkus-version` | version of Quarkus Platform BOM; the default value is looked up in Quarkus Extension Registry |  | String
 | `--quiet` | Will be quiet, only print when error occurs | false | boolean
 | `--repo,--repos` | Additional maven repositories for download on-demand (Use commas to separate multiple repositories) |  | String

docs/user-manual/modules/ROOT/pages/jbang-commands/camel-jbang-dependency-update.adoc

@@ -60,7 +60,6 @@ camel dependency update [options]
 | `--quarkus-artifact-id` _(deprecated)_ | Deprecated. This value is not used anymore. It is kept only for backwards compatibility and will be removed in Camel 5.x. Camel commands may use either 'quarkus-bom' or 'quarkus-camel-bom' artifactIds depending on the context. | quarkus-bom | String
 | `--quarkus-ext-registry` | The base URI of Quarkus Extension Registry. The default is {@value RuntimeType#QUARKUS_EXTENSION_REGISTRY_BASE_URL} unless camel.jbang.quarkus.platform.url system property is set (the /client/platforms suffix is removed if present). |  | String
 | `--quarkus-group-id` | groupId of Quarkus Platform BOM; honored only if --quarkus-version is set | io.quarkus.platform | String
-| `--quarkus-package-type` | Quarkus package type (uber-jar or fast-jar) | fast-jar | String
 | `--quarkus-version` | version of Quarkus Platform BOM; the default value is looked up in Quarkus Extension Registry |  | String
 | `--quiet` | Will be quiet, only print when error occurs | false | boolean
 | `--repo,--repos` | Additional maven repositories for download on-demand (Use commas to separate multiple repositories) |  | String

docs/user-manual/modules/ROOT/pages/jbang-commands/camel-jbang-export.adoc

@@ -58,7 +58,6 @@ camel export [options]
 | `--quarkus-artifact-id` _(deprecated)_ | Deprecated. This value is not used anymore. It is kept only for backwards compatibility and will be removed in Camel 5.x. Camel commands may use either 'quarkus-bom' or 'quarkus-camel-bom' artifactIds depending on the context. | quarkus-bom | String
 | `--quarkus-ext-registry` | The base URI of Quarkus Extension Registry. The default is {@value RuntimeType#QUARKUS_EXTENSION_REGISTRY_BASE_URL} unless camel.jbang.quarkus.platform.url system property is set (the /client/platforms suffix is removed if present). |  | String
 | `--quarkus-group-id` | groupId of Quarkus Platform BOM; honored only if --quarkus-version is set | io.quarkus.platform | String
-| `--quarkus-package-type` | Quarkus package type (uber-jar or fast-jar) | fast-jar | String
 | `--quarkus-version` | version of Quarkus Platform BOM; the default value is looked up in Quarkus Extension Registry |  | String
 | `--quiet` | Will be quiet, only print when error occurs | false | boolean
 | `--repo,--repos` | Additional maven repositories for download on-demand (Use commas to separate multiple repositories) |  | String

docs/user-manual/modules/ROOT/pages/jbang-commands/camel-jbang-sbom.adoc

@@ -61,7 +61,6 @@ camel sbom [options]
 | `--quarkus-artifact-id` _(deprecated)_ | Deprecated. This value is not used anymore. It is kept only for backwards compatibility and will be removed in Camel 5.x. Camel commands may use either 'quarkus-bom' or 'quarkus-camel-bom' artifactIds depending on the context. | quarkus-bom | String
 | `--quarkus-ext-registry` | The base URI of Quarkus Extension Registry. The default is {@value RuntimeType#QUARKUS_EXTENSION_REGISTRY_BASE_URL} unless camel.jbang.quarkus.platform.url system property is set (the /client/platforms suffix is removed if present). |  | String
 | `--quarkus-group-id` | groupId of Quarkus Platform BOM; honored only if --quarkus-version is set | io.quarkus.platform | String
-| `--quarkus-package-type` | Quarkus package type (uber-jar or fast-jar) | fast-jar | String
 | `--quarkus-version` | version of Quarkus Platform BOM; the default value is looked up in Quarkus Extension Registry |  | String
 | `--quiet` | Will be quiet, only print when error occurs | false | boolean
 | `--repo,--repos` | Additional maven repositories for download on-demand (Use commas to separate multiple repositories) |  | String

dsl/camel-jbang/camel-jbang-core/src/main/java/org/apache/camel/dsl/jbang/core/commands/Export.java

@@ -321,18 +321,23 @@ protected void copyDockerFiles(String buildDir) throws Exception {
         model.put("Version", ids[2]);
         model.put("AppJar", ids[1] + "-" + ids[2] + ".jar");
 
-        String ftlName = "Dockerfile" + javaVersion + ".ftl";
+        String ftlName = getDockerfileTemplateName() + javaVersion + ".ftl";
         String context;
         try {
             context = TemplateHelper.processTemplate(ftlName, model);
         } catch (IOException e) {
             // fallback to JDK 21 template
+            String fallback = getDockerfileTemplateName() + "21.ftl";
             printer().printf("No Dockerfile template for Java %s, falling back to Java 21 template%n", javaVersion);
-            context = TemplateHelper.processTemplate("Dockerfile21.ftl", model);
+            context = TemplateHelper.processTemplate(fallback, model);
         }
         Files.writeString(docker.resolve("Dockerfile"), context);
     }
 
+    protected String getDockerfileTemplateName() {
+        return "Dockerfile";
+    }
+
     // Copy the readme.md into the same Maven project root directory.
     protected void copyReadme(String buildDir, String appJar) throws Exception {
         String[] ids = gav.split(":");

dsl/camel-jbang/camel-jbang-core/src/main/java/org/apache/camel/dsl/jbang/core/commands/ExportBaseCommand.java

@@ -194,9 +194,11 @@ public abstract class ExportBaseCommand extends CamelCommand {
     @CommandLine.Mixin
     protected QuarkusPlatformMixin quarkusPlatform;
 
+    @Deprecated
     @CommandLine.Option(names = { "--quarkus-package-type" },
-                        description = "Quarkus package type (uber-jar or fast-jar)",
-                        defaultValue = "fast-jar")
+                        description = "Deprecated: Quarkus always uses fast-jar (layered) packaging",
+                        defaultValue = "fast-jar",
+                        hidden = true)
     protected String quarkusPackageType = "fast-jar";
 
     @CommandLine.Option(names = { "--maven-wrapper" }, defaultValue = "true",

dsl/camel-jbang/camel-jbang-core/src/main/java/org/apache/camel/dsl/jbang/core/commands/ExportQuarkus.java

@@ -319,15 +319,14 @@ protected String applicationPropertyLine(String key, String value) {
     protected void copyDockerFiles(String buildDir) throws Exception {
         Path dockerSrc = Path.of(buildDir).resolve("src/main/docker");
         if ("uber-jar".equals(quarkusPackageType)) {
-            // For uber-jar, the generic Dockerfile works as-is
             super.copyDockerFiles(buildDir);
         } else {
-            // For fast-jar, use a Quarkus-specific JVM Dockerfile
             Files.createDirectories(dockerSrc);
-            InputStream is
-                    = ExportQuarkus.class.getClassLoader().getResourceAsStream("quarkus-docker/Dockerfile.jvm");
-            if (is != null) {
-                PathUtils.copyFromStream(is, dockerSrc.resolve("Dockerfile"), true);
+            try (InputStream is
+                    = ExportQuarkus.class.getClassLoader().getResourceAsStream("quarkus-docker/Dockerfile.jvm")) {
+                if (is != null) {
+                    PathUtils.copyFromStream(is, dockerSrc.resolve("Dockerfile"), false);
+                }
             }
         }
 
@@ -339,9 +338,11 @@ protected void copyDockerFiles(String buildDir) throws Exception {
 
         // Quarkus-specific Dockerfiles for native builds
         for (String dockerfile : List.of("Dockerfile.native", "Dockerfile.native-micro")) {
-            InputStream is = ExportQuarkus.class.getClassLoader().getResourceAsStream("quarkus-docker/" + dockerfile);
-            if (is != null) {
-                PathUtils.copyFromStream(is, dockerSrc.resolve(dockerfile), true);
+            try (InputStream is
+                    = ExportQuarkus.class.getClassLoader().getResourceAsStream("quarkus-docker/" + dockerfile)) {
+                if (is != null) {
+                    PathUtils.copyFromStream(is, dockerSrc.resolve(dockerfile), false);
+                }
             }
         }
     }

dsl/camel-jbang/camel-jbang-core/src/main/java/org/apache/camel/dsl/jbang/core/commands/ExportSpringBoot.java

@@ -385,6 +385,11 @@ private static String legacyMavenRepositoriesAsPomXml(String repos) {
         return sb.toString();
     }
 
+    @Override
+    protected String getDockerfileTemplateName() {
+        return "Dockerfile-spring-boot";
+    }
+
     @Override
     protected Set<String> resolveDependencies(Path settings, Path profile) throws Exception {
         Set<String> answer = super.resolveDependencies(settings, profile);

dsl/camel-jbang/camel-jbang-core/src/main/resources/templates/Dockerfile-spring-boot21.ftl

@@ -0,0 +1,67 @@
+<#--
+
+    Licensed to the Apache Software Foundation (ASF) under one or more
+    contributor license agreements.  See the NOTICE file distributed with
+    this work for additional information regarding copyright ownership.
+    The ASF licenses this file to You under the Apache License, Version 2.0
+    (the "License"); you may not use this file except in compliance with
+    the License.  You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+
+-->
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+####
+# Multi-stage layered Dockerfile for Spring Boot (container-optimized).
+#
+# Uses Spring Boot's built-in layer extraction to produce optimized Docker layers.
+# Dependencies (most stable) are copied first, application code (most volatile) last.
+#
+# ./mvnw clean package
+# docker build -f src/main/docker/Dockerfile -t [=ArtifactId]:[=Version] .
+# docker run -it [=ArtifactId]:[=Version]
+#
+###
+
+# Stage 1: Extract Spring Boot layers
+FROM registry.access.redhat.com/ubi9/openjdk-21:1.24 AS builder
+WORKDIR /builder
+COPY target/[=AppJar] application.jar
+RUN java -Djarmode=tools -jar application.jar extract --layers --destination extracted
+
+# Stage 2: Build the optimized image
+FROM registry.access.redhat.com/ubi9/openjdk-21-runtime:1.24
+
+COPY --from=builder --chown=185 /builder/extracted/dependencies/ /deployments/
+COPY --from=builder --chown=185 /builder/extracted/spring-boot-loader/ /deployments/
+COPY --from=builder --chown=185 /builder/extracted/snapshot-dependencies/ /deployments/
+COPY --from=builder --chown=185 /builder/extracted/application/ /deployments/
+
+# Uncomment to expose any given port
+# EXPOSE 8080
+USER 185
+WORKDIR /deployments
+
+ENTRYPOINT ["java", "-jar", "application.jar"]

dsl/camel-jbang/camel-jbang-core/src/main/resources/templates/Dockerfile-spring-boot25.ftl

@@ -0,0 +1,67 @@
+<#--
+
+    Licensed to the Apache Software Foundation (ASF) under one or more
+    contributor license agreements.  See the NOTICE file distributed with
+    this work for additional information regarding copyright ownership.
+    The ASF licenses this file to You under the Apache License, Version 2.0
+    (the "License"); you may not use this file except in compliance with
+    the License.  You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+
+-->
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+####
+# Multi-stage layered Dockerfile for Spring Boot (container-optimized).
+#
+# Uses Spring Boot's built-in layer extraction to produce optimized Docker layers.
+# Dependencies (most stable) are copied first, application code (most volatile) last.
+#
+# ./mvnw clean package
+# docker build -f src/main/docker/Dockerfile -t [=ArtifactId]:[=Version] .
+# docker run -it [=ArtifactId]:[=Version]
+#
+###
+
+# Stage 1: Extract Spring Boot layers
+FROM registry.access.redhat.com/ubi9/openjdk-25:1.24 AS builder
+WORKDIR /builder
+COPY target/[=AppJar] application.jar
+RUN java -Djarmode=tools -jar application.jar extract --layers --destination extracted
+
+# Stage 2: Build the optimized image
+FROM registry.access.redhat.com/ubi9/openjdk-25-runtime:1.24
+
+COPY --from=builder --chown=185 /builder/extracted/dependencies/ /deployments/
+COPY --from=builder --chown=185 /builder/extracted/spring-boot-loader/ /deployments/
+COPY --from=builder --chown=185 /builder/extracted/snapshot-dependencies/ /deployments/
+COPY --from=builder --chown=185 /builder/extracted/application/ /deployments/
+
+# Uncomment to expose any given port
+# EXPOSE 8080
+USER 185
+WORKDIR /deployments
+
+ENTRYPOINT ["java", "-jar", "application.jar"]

dsl/camel-jbang/camel-jbang-core/src/main/resources/templates/Dockerfile21.ftl

@@ -35,11 +35,15 @@
 
 ####
 # This Dockerfile is used in order to build a container that runs the Camel application
+# using layered packaging for optimized container image caching.
 #
 # ./mvnw clean package
 # docker build -f src/main/docker/Dockerfile -t [=ArtifactId]:[=Version] .
 # docker run -it [=ArtifactId]:[=Version]
 #
+# Dependencies are copied first (changes infrequently - cached layer),
+# then the application JAR (changes frequently - small layer).
+#
 # This image uses the `run-java.sh` script to run the application.
 # This scripts computes the command line to execute your Java application, and
 # includes memory/GC tuning.
@@ -100,15 +104,16 @@
 # when running the container
 #
 ###
-FROM registry.access.redhat.com/ubi9/openjdk-21:1.23
+FROM registry.access.redhat.com/ubi9/openjdk-21:1.24
 
-COPY --chown=185 target/[=AppJar] /deployments/
+# Copy dependencies first for better layer caching
+COPY --chown=185 target/lib/ /deployments/lib/
+# Copy application JAR (the .original is the thin JAR before repackaging)
+COPY --chown=185 target/[=AppJar].original /deployments/[=AppJar]
 
 # Uncomment to expose any given port
 # EXPOSE 8080
 USER 185
-# Uncomment to provide any Java option
-# ENV JAVA_OPTS=""
 ENV JAVA_APP_JAR="/deployments/[=AppJar]"
 
 ENTRYPOINT [ "/opt/jboss/container/java/run/run-java.sh" ]