Merge pull request #90 from kumadee/master

feat: Specify `targetStage` in multi-stage container build

docs/modules/ROOT/pages/goals/build.adoc

@@ -90,6 +90,13 @@ When this option is specified _and_ `pullAlways` is also specified, builds will
 |tags
 |An array consisting of one or more tags to attach to the built container image. Tags will be appended at the end of the image name.
 
+|targetStage
+|Set the target build stage to build. When building a Containerfile with multiple build stages, it can be used to specify an intermediate build stage by name as the final stage for the resulting image. Commands after the target stage is skipped.
+
+**Default value is**: `null` (not specified).
+
+**See**: https://docs.podman.io/en/latest/markdown/podman-build.1.html
+
 |containerFile
 |The name of the `Containerfile` to build. If you are using a `Dockerfile` you should change this parameter.
 

src/main/java/nl/lexemmens/podman/command/podman/PodmanBuildCommand.java

@@ -28,6 +28,7 @@ public class PodmanBuildCommand extends AbstractPodmanCommand {
     private static final String NO_CACHE_CMD = "--no-cache";
     private static final String BUILD_ARG_CMD = "--build-arg";
     private static final String PLATFORM_CMD = "--platform";
+    private static final String TARGET_STAGE_CMD = "--target";
     private static final String SUBCOMMAND = "build";
 
     private PodmanBuildCommand(Log log, PodmanConfiguration podmanConfig, CommandExecutorDelegate delegate) {
@@ -149,6 +150,17 @@ public Builder setPlatform(String platform){
             return this;
         }
 
+        /**
+         * Sets the platform for the resulting image rather using the default of the build system
+         *
+         * @param targetStage Sets the target build stage to build in a multi-stage build.
+         * @return This builder instance
+         */
+        public Builder setTargetStage(String targetStage){
+            command.withOption(TARGET_STAGE_CMD, targetStage);
+            return this;
+        }
+
         public Builder addBuildArgs(Map<String, String> args) {
             Map<String, String> allBuildArgs = new HashMap<>(args);
             allBuildArgs.putAll(getBuildArgsFromSystem());

src/main/java/nl/lexemmens/podman/config/image/AbstractImageBuildConfiguration.java

@@ -156,6 +156,15 @@ public abstract class AbstractImageBuildConfiguration {
     @Parameter
     protected String platform;
 
+    /**
+     * Specify the final target stage to build. It is passed to the "--target" option of podman.
+     * <p>
+     *
+     * @see "https://docs.podman.io/en/latest/markdown/podman-build.1.html"
+     */
+    @Parameter
+    protected String targetStage;
+
     /**
      * Will be set when this class is validated using the #initAndValidate() method
      */
@@ -340,6 +349,15 @@ public Optional<String> getPlatform(){
         return Optional.ofNullable(platform);
     }
 
+    /**
+     * Returns the final target stage to build.
+     *
+     * @return if set, the final target stage to build defined in Containerfile.
+     */
+    public Optional<String> getTargetStage(){
+        return Optional.ofNullable(targetStage);
+    }
+
     /**
      * Returns a boolean indicating whether this configuration is valid
      *
@@ -369,6 +387,7 @@ protected boolean isContainerFileEmpty(Log log, Path fullContainerFilePath) thro
     }
 
     protected void determineBuildStages(Log log, Path fullContainerFilePath) throws MojoExecutionException {
+        boolean foundTargetStage = false;
         try (Stream<String> containerFileStream = Files.lines(fullContainerFilePath)) {
             List<String> content = containerFileStream.collect(Collectors.toList());
             for (String line : content) {
@@ -377,7 +396,9 @@ protected void determineBuildStages(Log log, Path fullContainerFilePath) throws
                     isMultistageContainerFile = true;
 
                     String stage = matcher.group(3);
-
+                    if (Objects.equals(stage, targetStage)) {
+                        foundTargetStage = true;
+                    }
                     log.debug("Found a stage named: " + stage);
                 }
             }
@@ -386,6 +407,12 @@ protected void determineBuildStages(Log log, Path fullContainerFilePath) throws
             log.error(msg, e);
             throw new MojoExecutionException(msg, e);
         }
+
+        if (targetStage != null  && isMultistageContainerFile && !foundTargetStage) {
+            String msg = String.format("Target stage '%s' was not found in the given Containerfile.", targetStage);
+            log.error(msg);
+            throw new MojoExecutionException(msg);
+        }
     }
 
     /**
@@ -516,6 +543,15 @@ public void setContainerFileDir(File containerFileDir) {
         this.containerFileDir = containerFileDir;
     }
 
+    /**
+     * Sets the final target stage to build.
+     *
+     * @param targetStage The final target stage to build.
+     */
+    public void setTargetStage(String targetStage) {
+        this.targetStage = targetStage;
+    }
+
     /**
      * Retrieves a collection of build arguments to provide to podman build using --build-arg
      *

src/main/java/nl/lexemmens/podman/service/PodmanExecutorService.java

@@ -80,7 +80,12 @@ public List<String> build(SingleImageConfiguration image) throws MojoExecutionEx
         if (platform.isPresent()) {
             builder = builder.setPlatform(platform.get());
         }
-
+
+        Optional<String> targetStage = image.getBuild().getTargetStage();
+        if (targetStage.isPresent()) {
+            builder.setTargetStage(targetStage.get());
+        }
+
         builder.addBuildArgs(image.getBuild().getArgs());
 
         return builder.build().execute();

src/test/java/nl/lexemmens/podman/BuildMojoTest.java

@@ -826,6 +826,93 @@ public void testMultiStageBuildWithCustomTagPerStagePodman1x() throws MojoExecut
         );
     }
 
+    @Test
+    public void testMultiStageBuildWithUnknownTargetStageThrowsException() {
+        PodmanConfiguration podman = new TestPodmanConfigurationBuilder().setTlsVerify(TlsVerify.FALSE).build();
+        String unknownStage = "healthcheck-builder";
+        SingleImageConfiguration image = new TestSingleImageConfigurationBuilder("sample")
+                .setContainerfileDir("src/test/resources/multistagecontainerfile")
+                .setTags(new String[]{"0.2.1"})
+                .setCreateLatestTag(false)
+                .setTargetStage(unknownStage)
+                .build();
+
+        configureMojo(podman, image, true, false, false, true, true);
+        when(mavenProject.getBuild()).thenReturn(build);
+        when(build.getDirectory()).thenReturn("target");
+
+        try {
+            buildMojo.execute();
+            fail("Expected an exception, however none was thrown.");
+        } catch (MojoExecutionException e) {
+            assertEquals(String.format("Target stage '%s' was not found in the given Containerfile.", unknownStage), e.getMessage());
+        }
+    }
+
+    @Test
+    public void testMultiStageBuildWithGivenTargetStage() throws MojoExecutionException, IOException, URISyntaxException {
+        URI sampleBuildOutputUri = PushMojoTest.class.getResource("/multistagecontainerfile/samplebuildoutput-phase2.txt").toURI();
+        Path sampleBuildOutputPath = Paths.get(sampleBuildOutputUri);
+
+        List<String> buildOutputUnderTest;
+        try (Stream<String> buildSampleOutput = Files.lines(sampleBuildOutputPath)) {
+            buildOutputUnderTest = buildSampleOutput.collect(Collectors.toList());
+        }
+
+        Assertions.assertNotNull(buildOutputUnderTest);
+
+        String targetStage = "phase";
+        PodmanConfiguration podman = new TestPodmanConfigurationBuilder().setTlsVerify(TlsVerify.FALSE).build();
+        SingleImageConfiguration image = new TestSingleImageConfigurationBuilder("sample")
+                .setContainerfileDir("src/test/resources/multistagecontainerfile")
+                .setTags(new String[]{"0.2.1"})
+                .setCreateLatestTag(false)
+                .setTargetStage(targetStage)
+                .build();
+        configureMojo(podman, image, true, false, false, false, true);
+
+        when(mavenProject.getBuild()).thenReturn(build);
+        when(build.getDirectory()).thenReturn("target");
+        when(serviceHubFactory.createServiceHub(isA(Log.class), isA(MavenProject.class), isA(MavenFileFilter.class), isA(PodmanConfiguration.class), isA(SkopeoConfiguration.class), isA(Settings.class), isA(SettingsDecrypter.class), isA(MavenProjectHelper.class))).thenReturn(serviceHub);
+        when(serviceHub.getContainerfileDecorator()).thenReturn(containerfileDecorator);
+        when(serviceHub.getPodmanExecutorService()).thenReturn(podmanExecutorService);
+        when(serviceHub.getSecurityContextService()).thenReturn(securityContextService);
+        when(serviceHub.getMavenProjectHelper()).thenReturn(mavenProjectHelper);
+        when(podmanExecutorService.build(isA(SingleImageConfiguration.class))).thenReturn(buildOutputUnderTest);
+
+        buildMojo.execute();
+
+        // Verify logging
+        verify(log, times(1)).info("Detected multistage Containerfile...");
+
+        // At random verify some lines
+        verify(log, times(1)).debug("Processing line: 'STEP 1: FROM nexus.example:15000/adoptopenjdk/openjdk11:11.0.3 AS base'");
+        verify(log, times(1)).debug("Processing candidate: 'STEP 7: LABEL Build-User=sample-user2 Git-Repository-Url=null'");
+
+        // Verify stage detection
+        verify(log, times(1)).debug("Processing stage in Containerfile: base");
+        verify(log, times(1)).debug("Processing stage in Containerfile: phase");
+        verify(log, times(0)).debug("Processing stage in Containerfile: phase2");
+
+        // Verify hashes for stages
+        verify(log, times(1)).info("Final image for stage base is: 7e72c870614");
+        verify(log, times(1)).info("Final image for stage phase is: 7f55eab001a");
+        verify(log, times(0)).info("Final image for stage phase2 is: d2efc6645cb");
+
+        // Verify tagging image
+        verify(log, times(0)).info("Tagging container image 7f55eab001a from stage phase as registry.example.com/sample:0.2.1");
+        verify(log, times(0)).info("Tagging container image d2efc6645cb from stage phase2 as registry.example.com/sample:0.2.1");
+        verify(log, times(1)).info("Tagging container image 7f55eab001adf2dfeas8adc03ef847dd3d2b4fa42b4fa418ca4cdeb6eaef8f3b as registry.example.com/sample:0.2.1");
+
+        verify(podmanExecutorService, times(1)).tag("7f55eab001adf2dfeas8adc03ef847dd3d2b4fa42b4fa418ca4cdeb6eaef8f3b", "registry.example.com/sample:0.2.1");
+
+        verify(log, times(1)).info("Built container image.");
+
+        verifyContainerCatalog(
+                "registry.example.com/sample:0.2.1"
+        );
+    }
+
     private void configureMojo(PodmanConfiguration podman, SingleImageConfiguration image, boolean skipAuth, boolean skipAll, boolean skipBuild, boolean skipTag, boolean failOnMissingContainerFile) {
         buildMojo.podman = podman;
         buildMojo.skip = skipAll;

src/test/java/nl/lexemmens/podman/config/image/single/TestSingleImageConfigurationBuilder.java

@@ -123,6 +123,11 @@ public TestSingleImageConfigurationBuilder setPullAlways(boolean pullAlways) {
         return this;
     }
 
+    public TestSingleImageConfigurationBuilder setTargetStage(String targetStage){
+        image.getBuild().setTargetStage(targetStage);
+        return this;
+    }
+
     public SingleImageConfiguration build() {
         return image;
     }

src/test/java/nl/lexemmens/podman/service/PodmanExecutorServiceTest.java

@@ -627,6 +627,30 @@ public void testBuildWithCustomRootAndRunRootDir() throws MojoExecutionException
                 delegate.getCommandAsString());
     }
 
+    @Test
+    public void testTargetStage() throws MojoExecutionException {
+        when(mavenProject.getBuild()).thenReturn(build);
+        when(build.getDirectory()).thenReturn("target");
+
+        PodmanConfiguration podmanConfig = new TestPodmanConfigurationBuilder().setTlsVerify(TRUE).initAndValidate(mavenProject, log).build();
+        SingleImageConfiguration image = new TestSingleImageConfigurationBuilder("test_image")
+                .setFormat(OCI)
+                .setLayers(false)
+                .setContainerfileDir("src/test/resources")
+                .setTargetStage("phase2")
+                .initAndValidate(mavenProject, log, true)
+                .build();
+
+        String sampleImageHash = "this_would_normally_be_an_image_hash";
+        InterceptorCommandExecutorDelegate delegate = new InterceptorCommandExecutorDelegate(Collections.singletonList(sampleImageHash));
+        podmanExecutorService = new PodmanExecutorService(log, podmanConfig, delegate);
+
+        podmanExecutorService.build(image);
+
+        Assertions.assertEquals("podman build --tls-verify=true --format=oci --file="
+                + image.getBuild().getTargetContainerFile() + " --no-cache=false --layers=false --target=phase2 .", delegate.getCommandAsString());
+
+    }
 
     private static class InterceptorCommandExecutorDelegate implements CommandExecutorDelegate {
 

src/test/resources/multistagecontainerfile/samplebuildoutput-phase2.txt

@@ -0,0 +1,28 @@
+Building container image...
+STEP 1: FROM nexus.example:15000/adoptopenjdk/openjdk11:11.0.3 AS base
+Getting image source signatures
+Copying blob sha256:df15d82c4ffe976522b836c1f0c300e289f797cb2e302df1b7d0b917af7d3795
+Copying blob sha256:c29f4698c17768b4bf36dde25d584231424db9f4b9c9e67cce8980cfc50efbc1
+Copying blob sha256:b08df05e829707fdd711d6669671a0dd0431a20ca7ae89d7cd415e0025ba3a84
+Copying blob sha256:ad26192fb1166465550d702a8418c67ecda7b089149870f48673d8f0fb5ab8c1
+Copying blob sha256:95c2c089cb32f9959093f091b223b04c3a8e0e0aa8b703c0052ebfe9be5f0b3c
+Copying blob sha256:67300986eedeec2c7442a3b30e65142200b72dc72dc6da2e945a0f06d5e9183b
+Copying config sha256:c83be72afce332f5c3c3ae4992f3340479fee3115d7f449afebf39d0b6eb16b6
+Writing manifest to image destination
+Storing signatures
+STEP 2: LABEL Build-User=example Git-Repository-Url=null
+--> ab579b718da
+STEP 3: ENV RUN_CMD="exec java -jar a-sample-jar-file.jar"
+--> d8874e40423
+STEP 4: WORKDIR /application
+--> 932d8db203e
+STEP 5: ENTRYPOINT /application
+--> 7e72c870614
+STEP 6: FROM 7e72c870614c842cefe268dec15cd84d8abd64be16a0c4f76d4883846b1e6104 AS phase
+STEP 7: LABEL Build-User=sample-user2 Git-Repository-Url=null
+--> f6d4d237662
+STEP 8: COPY target/a-sample-jar-file.jar ./
+--> 1149d5e6695
+STEP 9: ENTRYPOINT ${RUN_CMD}
+--> 7f55eab001a
+7f55eab001adf2dfeas8adc03ef847dd3d2b4fa42b4fa418ca4cdeb6eaef8f3b