P2P Recipe Sharing App

A peer-to-peer distributed recipe-sharing system built in Rust. Nodes can store, replicate, and retrieve recipes over a lightweight TCP-based P2P protocol. The project includes full Docker support, multi-node Compose testing, and a clean multi-stage build.

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Project Goals

• Build a minimal but functional P2P protocol in Rust
• Support recipe storage, retrieval, discovery, and propagation
• Run multiple nodes locally with Docker Compose
• Use a production-ready Dockerfile with efficient build caching
• Provide a scalable architecture suitable for future features

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Project Plan

1. MVP

1.1 Core Features

• TCP peer listener
• Connect to initial peers
• Broadcast new recipes
• Store recipes in a JSON file
• Respond to GET/SET requests

1.2 Rust Components

• p2p/mod.rs → message protocol (PING, STORE, GET, RECIPE)
• storage.rs → JSON file read/write
• peer.rs → manage peer list
• server.rs → TCP listener
• client.rs → outgoing messages

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2. Multi-Stage Dockerfile

Requirements:

• Cache dependencies correctly
• Avoid missing src/main.rs during cargo fetch
• Minimize final image size

Output:

• Multi-stage builder (Rust)
• runtime (Debian slim) layer containing only the binary
• Includes SSL + CA certificates

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3. Build and Test With Docker Compose

Compose Goals:

• Run 3+ nodes
• Each node has its own data folder
• Nodes know each other using environment variables
• Expose ports but run isolated networks

Example:

docker compose up --build

Each container will run a P2P node that joins the network automatically.

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Running the Project

1. Build Docker image

docker build -t p2p-recipe .

2. Run a single node

docker run -p 4001:4001 p2p-recipe

3. Run multi-node network

docker compose up --build

4. Check logs

docker compose logs -f peer1

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Environment Variables

Variable Description

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P2P_PORT Port to listen on STORAGE_FILE_PATH Path to recipes.json file PEERS Comma-separated list of peer addresses

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Testing the P2P Network

With Compose running:

Store a recipe:

echo '{"title":"Soup"}'   | nc localhost 4001

Retrieve a recipe:

echo 'GET Soup' | nc localhost 4002

Check replication:

docker exec peer3 cat /data/recipes.json