yarn: migrate sample-nodejs-app example

[derasdf]

No description provided.

[gemini-code-assist]

Summary of Changes

Hello @derasdf, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request establishes a new, self-contained sample Node.js application, demonstrating a basic Express.js server. It integrates Yarn for dependency management and provides a Dockerfile for easy containerization, offering a complete example for testing and deployment within a containerized environment.

Highlights

• New Sample Application: A new sample Node.js application using Express.js was introduced, providing a basic web server.
• Yarn Integration: The project was configured to use Yarn for package management, including a generated yarn.lock file for deterministic dependency resolution.
• Docker Support: A Containerfile was added to enable Docker containerization of the Node.js application, facilitating easy deployment and testing.
• Development Configuration: Standard development configuration files such as .dockerignore, .editorconfig, and .gitattributes were included to ensure consistent project setup and behavior.

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Changelog

• .dockerignore
  • Added a new file to specify patterns for files and directories to be ignored by Docker builds.
• .editorconfig
  • Added a new file to define consistent coding styles across different editors and IDEs.
• .gitattributes
  • Added a new file to configure Git attributes, specifically for Yarn-related files.
• .gitignore
  • Updated the file to include new ignore patterns for Yarn-specific directories and files, such as .yarn/* and .pnp.*.
• Containerfile
  • Added a new Dockerfile to define the steps for building a Docker image for the Node.js application.
• README.md
  • Updated the content to describe the new sample Node.js app and provide instructions on how to run it using Yarn.
• index.js
  • Added a new file containing a simple Express.js server that listens on port 9000 and responds with 'Hello Dude!'.
• package.json
  • Added a new file defining the project metadata, scripts (start, test), and dependencies, including Express.js.
• yarn.lock
  • Added a new file generated by Yarn, which locks the versions of all project dependencies for reproducible builds.

Activity

• No human activity recorded for this pull request.

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[gemini-code-assist]

Code Review

This pull request migrates the sample NodeJS application to use Yarn, including a simple Express server, a Containerfile for building a container image, and the necessary Yarn configuration files. The changes are straightforward and set up a good foundation for the example.

My review includes several suggestions to improve the project:

• Optimizing the Containerfile for better Docker layer caching, which will speed up builds.
• Adhering to the conventions defined in .editorconfig by ensuring all files end with a newline.
• Improving the Node.js application by using environment variables for configuration (like the port), enhancing logging, and filling out package.json metadata.
• A few minor fixes like a typo in a log message.

These changes will make the example more robust, maintainable, and aligned with common best practices.

[gemini-code-assist]

To improve Docker build performance, it's better to copy only package.json, yarn.lock and the .yarn directory first, run yarn install, and then copy the rest of the application source code. This allows Docker to cache the dependencies layer and avoid reinstalling them on every code change. For example:

WORKDIR /src
COPY package.json yarn.lock ./
COPY .yarn ./.yarn
RUN yarn install
COPY . .

[gemini-code-assist]

The file should end with a newline. The .editorconfig file specifies insert_final_newline = true for all files.

[gemini-code-assist]

Hardcoding the port number makes the application less flexible. It's a good practice to read the port from an environment variable (e.g., process.env.PORT) and provide a default value if the environment variable is not set. This makes it easier to run the application in different environments, especially in containers.

Suggested change

	const port = 9000;
	const port = process.env.PORT || 9000;

[gemini-code-assist]

The current test script indicates that no tests are specified. Even for a sample application, including a basic test suite (e.g., using Jest or Mocha) would be a great addition to demonstrate best practices and ensure the application works as expected.

[gemini-code-assist]

The author field is empty. It's good practice to specify the author of the package.