first

.dockerignore

+# compiled output
+/dist
+/node_modules
+
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# OS
+.DS_Store
+
+# Tests
+/coverage
+/.nyc_output
+
+# IDEs and editors
+/.idea
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# IDE - VSCode
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+/data
+/output
+/config.yaml
+
+.git*
+Dockerfile
+.dockerignore
+/tests

.eslintignore

+webpack.config.js
+dist/*
+build/*
+*.js

.eslintrc.js

+module.exports = {
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    project: 'tsconfig.json',
+    sourceType: 'module',
+  },
+  plugins: ['@typescript-eslint/eslint-plugin'],
+  extends: [
+    'plugin:@typescript-eslint/recommended',
+    'plugin:prettier/recommended',
+  ],
+  root: true,
+  env: {
+    node: true,
+    jest: true,
+  },
+  ignorePatterns: ['.eslintrc.js'],
+  rules: {
+    '@typescript-eslint/interface-name-prefix': 'off',
+    '@typescript-eslint/explicit-function-return-type': 'off',
+    '@typescript-eslint/explicit-module-boundary-types': 'off',
+    '@typescript-eslint/no-explicit-any': 'off',
+  },
+};

.gitignore

+# compiled output
+/dist
+/node_modules
+
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# OS
+.DS_Store
+
+# Tests
+/coverage
+/.nyc_output
+
+# IDEs and editors
+/.idea
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# IDE - VSCode
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+/data
+/output
+/config.yaml

.gitlab-ci.upload.yml

+stages:
+  - install
+  - build
+  - deploy
+
+variables:
+  GIT_DEPTH: "1"
+
+npm_ci:
+  stage: install
+  tags:
+    - linux
+  script:
+    - npm ci
+  artifacts:
+    paths:
+      - node_modules
+
+.build_base:
+  stage: build
+  tags:
+    - linux
+  dependencies:
+    - npm_ci
+
+build:
+  extends: .build_base
+  script: npm run build
+  artifacts:
+    paths:
+      - dist/
+
+upload_to_minio:
+  stage: deploy
+  dependencies:
+    - build
+  tags:
+    - linux
+  script:
+    - aws s3 --endpoint=https://minio.momobako.com:9000 sync --delete dist/ s3://nanahira/path
+  only:
+    - master

.gitlab-ci.yml

+stages:
+  - build
+  - combine
+  - deploy
+variables:
+  GIT_DEPTH: "1"
+  CONTAINER_TEST_IMAGE: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG
+  CONTAINER_TEST_ARM_IMAGE: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG-arm
+  CONTAINER_TEST_X86_IMAGE: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG-x86
+  CONTAINER_RELEASE_IMAGE: $CI_REGISTRY_IMAGE:latest
+before_script:
+  - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+build-x86:
+  stage: build
+  tags:
+    - docker
+  script:
+    - TARGET_IMAGE=$CONTAINER_TEST_X86_IMAGE
+    - docker build --pull -t $TARGET_IMAGE .
+    - docker push $TARGET_IMAGE
+build-arm:
+  stage: build
+  tags:
+    - docker-arm
+  script:
+    - TARGET_IMAGE=$CONTAINER_TEST_ARM_IMAGE
+    - docker build --pull -t $TARGET_IMAGE .
+    - docker push $TARGET_IMAGE
+combine:
+  stage: combine
+  tags:
+    - docker
+  script:
+    - TARGET_IMAGE=$CONTAINER_TEST_IMAGE
+    - SOURCE_IMAGE_2=$CONTAINER_TEST_ARM_IMAGE
+    - SOURCE_IMAGE_1=$CONTAINER_TEST_X86_IMAGE
+    - docker pull $SOURCE_IMAGE_1
+    - docker pull $SOURCE_IMAGE_2
+    - docker manifest create $TARGET_IMAGE --amend $SOURCE_IMAGE_1 --amend
+      $SOURCE_IMAGE_2
+    - docker manifest push $TARGET_IMAGE
+deploy_latest:
+  stage: deploy
+  tags:
+    - docker
+  script:
+    - TARGET_IMAGE=$CONTAINER_RELEASE_IMAGE
+    - SOURCE_IMAGE=$CONTAINER_TEST_IMAGE
+    - docker pull $SOURCE_IMAGE
+    - docker tag $SOURCE_IMAGE $TARGET_IMAGE
+    - docker push $TARGET_IMAGE
+  only:
+    - master
+deploy_tag:
+  stage: deploy
+  tags:
+    - docker
+  script:
+    - TARGET_IMAGE=$CI_REGISTRY_IMAGE:$CI_COMMIT_TAG
+    - SOURCE_IMAGE=$CONTAINER_TEST_IMAGE
+    - docker pull $SOURCE_IMAGE
+    - docker tag $SOURCE_IMAGE $TARGET_IMAGE
+    - docker push $TARGET_IMAGE
+  only:
+    - tags

.npmignore

+/install-npm.sh
+.git*
+/data
+/output
+/config.yaml
+.idea
+.dockerignore
+Dockerfile
+/src
+/coverage
+/tests
+/dist/tests

.prettierrc

+{
+  "singleQuote": true,
+  "trailingComma": "all"
+}
\ No newline at end of file

Dockerfile

+FROM node:lts-bullseye-slim as base
+LABEL Author="Nanahira <nanahira@momobako.com>"
+
+RUN apt update && apt -y install python3 build-essential && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* /var/log/*
+WORKDIR /usr/src/app
+COPY ./package*.json ./
+
+FROM base as builder
+RUN npm ci && npm cache clean --force
+COPY . ./
+RUN npm run build
+
+FROM base
+ENV NODE_ENV production
+RUN npm ci && npm cache clean --force
+COPY --from=builder /usr/src/app/dist ./dist
+
+CMD [ "npm", "start" ]

LICENSE

+The MIT License (MIT)
+
+Copyright (c) 2021 Nanahira
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

README.md

 # Minecraft Stub
 
-Minecraft stub server
\ No newline at end of file
+Minecraft stub server
+
+## Environment
+
+- `PORT` - Minecraft server port
+- `MC_VERSION` - Minecraft version to use
+- `MC_MOTD` - Minecraft server MOTD
+- `MC_MAX` - Minecraft server max players
+- `MC_CURRENT_MIN` - Minecraft server current min players
+- `MC_CURRENT_MAX` - Minecraft server current max players
+- `MC_CURRENT_PLAYERS` - Minecraft server current players
+- `MC_REFRESH_COUNT` - Minecraft server ping refresh period count
+- `MC_KICK_MESSAGE` - Minecraft server kick message
+
+## Path
+
+- `/usr/src/app/icon.png` - Minecraft server icon

index.ts

+import net from 'net';
+import { createLogger } from 'bunyan';
+import { parsePacket, encode } from './src/decode';
+import { PingGenerator } from './src/ping';
+
+const server = net.createServer();
+const log = createLogger({ name: 'minecraft-stub' });
+const generator = new PingGenerator();
+
+server.on('error', (err) => {
+  log.error('Server error', err);
+});
+
+server.on('connection', (socket) => {
+  let buffer = Buffer.alloc(0);
+  socket.on('data', async (data) => {
+    buffer = Buffer.concat([buffer, data]);
+    const baseBuffer = buffer.slice(buffer.indexOf(0x00) + 1, buffer.length);
+    const baseHostname =
+      parsePacket.hostname(baseBuffer).length <= 10
+        ? parsePacket.hostname(baseBuffer).length + 10
+        : parsePacket.hostname(baseBuffer).length;
+    if (buffer.length < baseHostname && buffer.length > 10) return;
+    try {
+      const player = parsePacket.player(buffer, baseBuffer);
+      const protocol = parsePacket.protocol(baseBuffer);
+      const hostname = parsePacket.hostname(baseBuffer);
+      const port = parsePacket.port(baseBuffer);
+      const state = parsePacket.state(baseBuffer);
+
+      // Perhaps someone can change the logging message? :/
+      switch (state) {
+        case 1:
+          /*
+          Response handshake with server status
+          https://wiki.vg/Server_List_Ping#Handshake
+          */
+
+          log.info(
+            `Handshake is initiated with hostname ${hostname} and port ${port}`,
+          );
+
+          const config = await generator.generate(protocol);
+
+          socket.write(encode(config));
+          break;
+        case 2:
+          /*
+          Response when client tries to connect
+          https://wiki.vg/Protocol#Disconnect_.28login.29
+          */
+
+          log.info(`${player} is trying to connect to ${hostname}:${port}`);
+
+          socket.write(encode(generator.kickMessage(player)));
+          break;
+        default:
+          log.info(`Responding to ping`);
+          socket.write(buffer);
+          break;
+      }
+    } catch (error) {
+      log.error(error);
+    } finally {
+      buffer = Buffer.alloc(0);
+    }
+  });
+});
+
+const port = parseInt(process.env.PORT || '25565', 10);
+
+server.listen(port, null, () => {
+  log.info(`Fake Minecraft Server Listening in ${port}`);
+});

install-npm.sh

+#!/bin/bash
+
+npm install --save-dev \
+	@types/node \
+	typescript \
+	'@typescript-eslint/eslint-plugin@^4.28.2' \
+	'@typescript-eslint/parser@^4.28.2 '\
+	'eslint@^7.30.0' \
+	'eslint-config-prettier@^8.3.0' \
+	'eslint-plugin-prettier@^3.4.0' \
+	prettier \
+	jest \
+	@types/jest \
+	ts-jest \
+	rimraf

package.json

+{
+  "name": "myproject",
+  "description": "myproject-desc",
+  "version": "1.0.0",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "scripts": {
+    "lint": "eslint --fix .",
+    "build": "rimraf dist && tsc",
+    "test": "jest --passWithNoTests",
+    "start": "node dist/index.js | bunyan"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://code.mycard.moe/3rdeye/myproject.git"
+  },
+  "author": "Nanahira <nanahira@momobako.com>",
+  "license": "MIT",
+  "keywords": [],
+  "bugs": {
+    "url": "https://code.mycard.moe/3rdeye/myproject/issues"
+  },
+  "homepage": "https://code.mycard.moe/3rdeye/myproject",
+  "jest": {
+    "moduleFileExtensions": [
+      "js",
+      "json",
+      "ts"
+    ],
+    "rootDir": "tests",
+    "testRegex": ".*\\.spec\\.ts$",
+    "transform": {
+      "^.+\\.(t|j)s$": "ts-jest"
+    },
+    "collectCoverageFrom": [
+      "**/*.(t|j)s"
+    ],
+    "coverageDirectory": "../coverage",
+    "testEnvironment": "node"
+  },
+  "devDependencies": {
+    "@types/bunyan": "^1.8.8",
+    "@types/jest": "^28.1.1",
+    "@types/node": "^18.0.0",
+    "@typescript-eslint/eslint-plugin": "^4.33.0",
+    "@typescript-eslint/parser": "^4.33.0",
+    "eslint": "^7.32.0",
+    "eslint-config-prettier": "^8.5.0",
+    "eslint-plugin-prettier": "^3.4.1",
+    "jest": "^28.1.1",
+    "prettier": "^2.7.1",
+    "rimraf": "^3.0.2",
+    "ts-jest": "^28.0.5",
+    "typescript": "^4.7.3"
+  },
+  "dependencies": {
+    "bunyan": "^1.8.15",
+    "make-random": "^3.0.2"
+  }
+}

src/decode.ts

+const leb = {
+  encode: (value) => {
+    value |= 0;
+    const result = [];
+    while (true) {
+      const byte = value & 0x7f;
+      value >>= 7;
+      if (
+        (value === 0 && (byte & 0x40) === 0) ||
+        (value === -1 && (byte & 0x40) !== 0)
+      ) {
+        result.push(byte);
+        return Buffer.from(result);
+      }
+      result.push(byte | 0x80);
+    }
+  },
+  decode: (input) => {
+    let result = 0;
+    let shift = 0;
+    while (true) {
+      const byte = input.shift();
+      result |= (byte & 0x7f) << shift;
+      shift += 7;
+      if ((0x80 & byte) === 0) {
+        if (shift < 32 && (byte & 0x40) !== 0) {
+          return result | (~0 << shift);
+        }
+        return result;
+      }
+    }
+  },
+};
+
+export const parsePacket = {
+  hostname: (buffer: Buffer) => {
+    const val1 = 3;
+    const val2 =
+      buffer.indexOf(0x00) == -1 ? buffer.length - 3 : buffer.indexOf(0x00) - 4;
+
+    const result = buffer.slice(val1, val2).toString('utf8');
+
+    return result;
+  },
+  port: (buffer: Buffer) => {
+    const val1 =
+      buffer.indexOf(0x00) == -1 ? buffer.length - 3 : buffer.indexOf(0x00) - 4;
+    const val2 =
+      buffer.indexOf(0x00) == -1 ? buffer.length - 1 : buffer.indexOf(0x00) - 2;
+
+    const result = buffer.slice(val1, val2).readUInt16BE();
+    return result;
+  },
+  protocol: (buffer: Buffer) => {
+    return leb.decode(Array.prototype.slice.call(buffer.slice(0, 2)));
+  },
+  player: (rawBuffer: Buffer, buffer: Buffer) => {
+    if (buffer.indexOf(0x00) == -1) return '';
+    const val1 = buffer.indexOf(0x00) + 2;
+    const val2 = rawBuffer.length;
+
+    const result = buffer.slice(val1, val2).toString('utf8');
+
+    return result;
+  },
+  state: (buffer) => {
+    const val1 =
+      buffer.indexOf(0x00) == -1 ? buffer.length - 1 : buffer.indexOf(0x00) - 2;
+    const val2 =
+      buffer.indexOf(0x00) == -1 ? buffer.length : buffer.indexOf(0x00) - 1;
+
+    const result = buffer.slice(val1, val2).readInt8();
+
+    return result;
+  },
+};
+
+export function encode(data: any) {
+  data = Buffer.from(JSON.stringify(data), 'utf-8');
+  return Buffer.concat([
+    leb.encode(data.byteLength + leb.encode(data.byteLength).byteLength + 1),
+    Buffer.alloc(1),
+    leb.encode(data.byteLength),
+    data,
+  ]);
+}

src/ping.ts

+import fs from 'fs';
+import { randomEnglish, randomUUID } from 'make-random';
+
+export interface Ping {
+  version: Version;
+  players: Players;
+  description: Description;
+  favicon: string;
+}
+
+export interface Description {
+  text: string;
+}
+
+export interface Players {
+  max: number;
+  online: number;
+  sample: Sample[];
+}
+
+export interface Sample {
+  name: string;
+  id: string;
+}
+
+export interface Version {
+  name: string;
+  protocol: number;
+}
+
+export class PingGenerator {
+  private icon: string;
+  private players: Players;
+  private max = 20;
+  private currentMax = 10;
+  private currentMin = 5;
+
+  private refreshPeriod = 100;
+  private pointer = 0;
+
+  async refreshPlayers() {
+    this.pointer = 0;
+    this.players = {
+      max: this.max,
+      online:
+        Math.floor(Math.random() * (this.currentMax - this.currentMin + 1)) +
+        this.currentMin,
+      sample: [
+        {
+          name: await randomEnglish(1),
+          id: await randomUUID(),
+        },
+      ],
+    };
+  }
+
+  async getPlayers() {
+    if (!this.players || ++this.pointer >= this.refreshPeriod) {
+      await this.refreshPlayers();
+    }
+    return this.players;
+  }
+
+  async generate(protocol: number): Promise<Ping> {
+    return {
+      version: {
+        name: process.env.MC_VERSION || '1.12.2',
+        protocol,
+      },
+      players: await this.getPlayers(),
+      description: {
+        text: process.env.MC_MOTD || 'A Minecraft server',
+      },
+      favicon: this.icon ? `data:image/png;base64,${this.icon}` : undefined,
+    };
+  }
+
+  load;
+
+  constructor() {
+    if (process.env.MC_MAX) {
+      this.max = parseInt(process.env.MC_MAX);
+    }
+    if (process.env.MC_CURRENT_MAX) {
+      this.currentMax = parseInt(process.env.MC_CURRENT_MAX);
+    }
+    if (process.env.MC_CURRENT_MIN) {
+      this.currentMin = parseInt(process.env.MC_CURRENT_MIN);
+    }
+    if (process.env.MC_REFRESH_COUNT) {
+      this.refreshPeriod = parseInt(process.env.MC_REFRESH_COUNT);
+    }
+    fs.promises
+      .readFile('./icon.png', 'base64')
+      .then((data) => {
+        this.icon = data;
+      })
+      .catch();
+  }
+  kickMessage(name: string) {
+    const message =
+      process.env.MC_KICK_MESSAGE ||
+      'You ({name}) are not allowed to join this server.';
+    return message.replaceAll('{name}', name);
+  }
+}

tests/sample.spec.ts

+describe('Sample test.', () => {
+  it('should pass', () => {
+    expect(true).toBe(true);
+  });
+});

tsconfig.json

+{
+	"compilerOptions": {
+		"outDir": "dist",
+		"module": "commonjs",
+		"target": "es2021",
+		"esModuleInterop": true,
+		"emitDecoratorMetadata": true,
+		"experimentalDecorators": true,
+		"declaration": true,
+		"sourceMap": true
+	},
+	"compileOnSave": true,
+	"allowJs": true,
+	"include": [
+		"*.ts",
+		"src/**/*.ts",
+		"test/**/*.ts",
+		"tests/**/*.ts"
+	]
+}