fix typo + compiled files

compiled_starters/java/.gitattributes

@@ -0,0 +1 @@
+* text=auto

compiled_starters/java/.gitignore

@@ -0,0 +1,4 @@
+java_docker.jar
+target/*
+target/
+.idea/

compiled_starters/java/Dockerfile

@@ -0,0 +1,15 @@
+FROM maven:3.9.4-eclipse-temurin-8-alpine
+
+RUN apk add curl
+
+# Download docker-explorer
+ARG docker_explorer_version=v18
+RUN curl -Lo /usr/local/bin/docker-explorer https://github.com/codecrafters-io/docker-explorer/releases/download/${docker_explorer_version}/${docker_explorer_version}_linux_amd64
+RUN chmod +x /usr/local/bin/docker-explorer
+
+ADD . /app
+WORKDIR /app
+
+RUN sed -i -e 's/\r$//' /app/your_docker.sh
+
+ENTRYPOINT ["/app/your_docker.sh"]

compiled_starters/java/README.md

@@ -0,0 +1,52 @@
+![progress-banner](https://codecrafters.io/landing/images/default_progress_banners/docker.png)
+
+This is a starting point for Java solutions to the
+["Build Your Own Docker" Challenge](https://codecrafters.io/challenges/docker).
+
+In this challenge, you'll build a program that can pull an image from
+[Docker Hub](https://hub.docker.com/) and execute commands in it. Along the way,
+we'll learn about [chroot](https://en.wikipedia.org/wiki/Chroot),
+[kernel namespaces](https://en.wikipedia.org/wiki/Linux_namespaces), the
+[docker registry API](https://docs.docker.com/registry/spec/api/) and much more.
+
+**Note**: If you're viewing this repo on GitHub, head over to
+[codecrafters.io](https://codecrafters.io) to try the challenge.
+
+# Passing the first stage
+
+The entry point for your Docker implementation is `src/main/java/Main.java`.
+Study and uncomment the relevant code, and push your changes to pass the first
+stage:
+
+```sh
+git add .
+git commit -m "pass 1st stage" # any msg
+git push origin master
+```
+
+That's all!
+
+# Stage 2 & beyond
+
+Note: This section is for stages 2 and beyond.
+
+You'll use linux-specific syscalls in this challenge. so we'll run your code
+_inside_ a Docker container.
+
+Please ensure you have [Docker installed](https://docs.docker.com/get-docker/)
+locally.
+
+Next, add a [shell alias](https://shapeshed.com/unix-alias/):
+
+```sh
+alias mydocker='docker build -t mydocker . && docker run --cap-add="SYS_ADMIN" mydocker'
+```
+
+(The `--cap-add="SYS_ADMIN"` flag is required to create
+[PID Namespaces](https://man7.org/linux/man-pages/man7/pid_namespaces.7.html))
+
+You can now execute your program like this:
+
+```sh
+mydocker run ubuntu:latest /usr/local/bin/docker-explorer echo hey
+```

compiled_starters/java/codecrafters.yml

@@ -0,0 +1,11 @@
+# Set this to true if you want debug logs.
+#
+# These can be VERY verbose, so we suggest turning them off
+# unless you really need them.
+debug: false
+
+# Use this to change the Java version used to run your code
+# on Codecrafters.
+#
+# Available versions: java-1.8
+language_pack: java-1.8

compiled_starters/java/pom.xml

@@ -0,0 +1,83 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>io.codecrafters</groupId>
+    <artifactId>build-your-own-bittorrent</artifactId>
+    <version>1.0</version>
+
+    <properties>
+        <maven.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <java.version>8</java.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.dampcake</groupId>
+            <artifactId>bencode</artifactId>
+            <version>1.4.1</version>
+        </dependency>
+        <dependency>
+            <groupId>net.java.dev.jna</groupId>
+            <artifactId>jna-platform</artifactId>
+            <version>5.12.1</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.30</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>2.10.1</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>${java.version}</source>
+                    <target>${java.version}</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <configuration>
+                    <finalName>java_docker</finalName> <!-- Please do not change this final artifact name-->
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                    <appendAssemblyId>false</appendAssemblyId>
+                    <archive>
+                        <manifest>
+                            <addClasspath>true</addClasspath>
+                            <!-- This is the main class of your program which will be executed-->
+                            <mainClass>Main</mainClass>
+                        </manifest>
+                    </archive>
+                    <outputDirectory>${dir}</outputDirectory>
+                </configuration>
+
+                <executions>
+                    <execution>
+                        <id>make-assembly</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

compiled_starters/java/src/main/java/Main.java

@@ -0,0 +1,56 @@
+import com.sun.jna.Library;
+import com.sun.jna.Native;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardCopyOption;
+import java.util.Arrays;
+
+// your_docker.sh run <image>       <command> <arg1> <arg2> ...
+//                run ubuntu:latest /usr/local/bin/docker-explorer exit 1
+//                run ubuntu:latest /usr/local/bin/docker-explorer ls /some_dir
+//                run ubuntu:latest echo hey
+public class Main {
+
+  public interface LibC extends Library {
+    // GO: <CLONE_NEWPID = 0x20000000 // New pid namespace>
+    int CLONE_NEWPID_NAMESPACE_FLAG = 0x20000000;
+
+    int chroot(String path); // Define the JNA interface for libc, which includes the chroot function
+
+    int unshare(int flags);
+  }
+
+
+  public static void main(String[] args) {
+    // You can use print statements as follows for debugging, they'll be visible when running tests.
+    System.out.println("Logs from your program will appear here!");
+
+    // Uncomment this block to pass the first stage!
+    // System.out.println(Arrays.toString(args));
+    // String imageName = args[1];
+    // String command = args[2];
+    // String[] commandWithArgs = Arrays.copyOfRange(args, 2, args.length);
+    // try {
+    //   ProcessBuilder processBuilder = new ProcessBuilder(commandWithArgs);
+    //   processBuilder.redirectOutput(ProcessBuilder.Redirect.INHERIT);
+    //   processBuilder.redirectError(ProcessBuilder.Redirect.INHERIT);
+    //
+    //   Process process = processBuilder.start();
+    // 
+    //   int exitCode = process.waitFor();
+    // 
+    //   if (exitCode != 0) {
+    //     System.err.printf("Err: %d\n", exitCode);
+    //     System.exit(1);
+    //   }
+    // } catch (IOException | InterruptedException e) {
+    //   System.err.printf("Err: %s\n", e.getMessage());
+    //   System.exit(1);
+    // }
+
+
+}

compiled_starters/java/your_docker.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+#
+# DON'T EDIT THIS!
+#
+# CodeCrafters uses this file to test your code. Don't make any changes here!
+#
+# DON'T EDIT THIS!
+set -e
+
+ls -alh
+
+mvn -B --quiet package -Ddir=/tmp/codecrafters-docker-target
+exec java -jar /tmp/codecrafters-docker-target/java_docker.jar "$@"

course-definition.yml

@@ -36,7 +36,6 @@ languages:
 
   - slug: "java"
     release_status: "alpha"
-    alpha_tester_usernames: ["anugrahsinghal"]
 
   - slug: "swift"
     release_status: "alpha"

dockerfiles/java-1.8.Dockerfile

@@ -1,4 +1,4 @@
-FROM maven:3.9.4-eclipse-temurin-11-alpine
+FROM maven:3.9.4-eclipse-temurin-8-alpine
 
 RUN apk add curl
 

solutions/java/01-init/code/.gitattributes

@@ -0,0 +1 @@
+* text=auto

solutions/java/01-init/code/.gitignore

@@ -0,0 +1,4 @@
+java_docker.jar
+target/*
+target/
+.idea/

solutions/java/01-init/code/Dockerfile

@@ -0,0 +1,15 @@
+FROM maven:3.9.4-eclipse-temurin-8-alpine
+
+RUN apk add curl
+
+# Download docker-explorer
+ARG docker_explorer_version=v18
+RUN curl -Lo /usr/local/bin/docker-explorer https://github.com/codecrafters-io/docker-explorer/releases/download/${docker_explorer_version}/${docker_explorer_version}_linux_amd64
+RUN chmod +x /usr/local/bin/docker-explorer
+
+ADD . /app
+WORKDIR /app
+
+RUN sed -i -e 's/\r$//' /app/your_docker.sh
+
+ENTRYPOINT ["/app/your_docker.sh"]

solutions/java/01-init/code/README.md

@@ -0,0 +1,52 @@
+![progress-banner](https://codecrafters.io/landing/images/default_progress_banners/docker.png)
+
+This is a starting point for Java solutions to the
+["Build Your Own Docker" Challenge](https://codecrafters.io/challenges/docker).
+
+In this challenge, you'll build a program that can pull an image from
+[Docker Hub](https://hub.docker.com/) and execute commands in it. Along the way,
+we'll learn about [chroot](https://en.wikipedia.org/wiki/Chroot),
+[kernel namespaces](https://en.wikipedia.org/wiki/Linux_namespaces), the
+[docker registry API](https://docs.docker.com/registry/spec/api/) and much more.
+
+**Note**: If you're viewing this repo on GitHub, head over to
+[codecrafters.io](https://codecrafters.io) to try the challenge.
+
+# Passing the first stage
+
+The entry point for your Docker implementation is `src/main/java/Main.java`.
+Study and uncomment the relevant code, and push your changes to pass the first
+stage:
+
+```sh
+git add .
+git commit -m "pass 1st stage" # any msg
+git push origin master
+```
+
+That's all!
+
+# Stage 2 & beyond
+
+Note: This section is for stages 2 and beyond.
+
+You'll use linux-specific syscalls in this challenge. so we'll run your code
+_inside_ a Docker container.
+
+Please ensure you have [Docker installed](https://docs.docker.com/get-docker/)
+locally.
+
+Next, add a [shell alias](https://shapeshed.com/unix-alias/):
+
+```sh
+alias mydocker='docker build -t mydocker . && docker run --cap-add="SYS_ADMIN" mydocker'
+```
+
+(The `--cap-add="SYS_ADMIN"` flag is required to create
+[PID Namespaces](https://man7.org/linux/man-pages/man7/pid_namespaces.7.html))
+
+You can now execute your program like this:
+
+```sh
+mydocker run ubuntu:latest /usr/local/bin/docker-explorer echo hey
+```

solutions/java/01-init/code/codecrafters.yml

@@ -0,0 +1,11 @@
+# Set this to true if you want debug logs.
+#
+# These can be VERY verbose, so we suggest turning them off
+# unless you really need them.
+debug: false
+
+# Use this to change the Java version used to run your code
+# on Codecrafters.
+#
+# Available versions: java-1.8
+language_pack: java-1.8