GradleContainerDemo.java

import com.github.dockerjava.api.DockerClient;
import com.github.dockerjava.api.async.ResultCallback;
import com.github.dockerjava.api.model.WaitResponse;
import lombok.SneakyThrows;
import org.eclipse.jgit.api.ArchiveCommand;
import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.archive.TarFormat;
import org.eclipse.jgit.errors.RepositoryNotFoundException;
import org.testcontainers.containers.GenericContainer;
import org.testcontainers.containers.startupcheck.StartupCheckStrategy;
import org.testcontainers.utility.DockerImageName;
import org.testcontainers.utility.MountableFile;

import java.awt.desktop.SystemSleepEvent;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Files;
import java.util.concurrent.atomic.AtomicReference;

public class GradleContainerDemo {
    public static class GradleContainer extends GenericContainer<GradleContainer> {
        public GradleContainer(DockerImageName imageName) {
            super(imageName);
            //noinspection resource
            withStartupCheckStrategy(new StartupCheckStrategy() {
                @Override
                public StartupStatus checkStartupState(DockerClient dockerClient, String containerId) {
                    return StartupStatus.SUCCESSFUL;
                }
            });
        }

        @Override
        public void start() {
            super.start();
            followOutput(s -> logger().info(s.getUtf8String()));
            waitForContainerExit();
        }

        @SneakyThrows
        public void waitForContainerExit() {
            dockerClient.waitContainerCmd(getContainerId()).exec(new ResultCallback.Adapter<>() {
                @Override
                public void onNext(WaitResponse object) {
                    logger().info("waitResponse: {}", object);
                }
            }).awaitCompletion();
        }

        @Override
        public StartupCheckStrategy getStartupCheckStrategy() {
            return new StartupCheckStrategy() {
                @Override
                public StartupStatus checkStartupState(DockerClient dockerClient, String containerId) {
                    return StartupStatus.SUCCESSFUL;
                }
            };
        }
    }

    @SneakyThrows
    public static void main(String[] args) {
        ArchiveCommand.registerFormat("tar", new TarFormat());

        FileOutputStream fos;
        String filename;
        var dir = new File(System.getProperty("user.dir")); // use rootProject.projectDir or whatever in gradle
        try (Git git = Git.open(dir)) {
            var branch = git.getRepository().getBranch();
            filename = "archive-" + branch + "-" + System.currentTimeMillis() + ".tar";
            OutputStream tar = git.archive()
                    .setFormat("tar")
                    .setTree(git.getRepository().resolve(branch))
                    .setFilename(filename)
                    .setOutputStream(fos = new FileOutputStream(filename))
                    .call();
            tar.close();
            fos.flush();
            fos.close();
            Runtime.getRuntime().addShutdownHook(new Thread(() -> {
                try {
                    Files.delete(new File(filename).toPath());
                } catch (IOException ignored) {
                }
            }));
        } catch (RepositoryNotFoundException rnfe) {
            throw new RuntimeException("could not find repo", rnfe);
        }

        try (GradleContainer g = new GradleContainer(
                DockerImageName.parse("gradle")
                        .withTag("jdk17-alpine"))) {
            g
                    .withCopyFileToContainer(MountableFile.forHostPath(filename), "/repo.tar")
                    // todo abstract the ugliness (meanwhile avert your eyes)
                    // is busy box acts up again, add "apk add tar"
                    .withCommand("sh", "-c", """
                            mkdir /repo && \
                            tar xf /repo.tar -C /repo && \
                            cd /repo && \
                            gradle tasks
                            """);

            g.start();
        }
    }
}