Dockerfile

# MCP-Compliant Dockerfile for Hugging Face Spaces deployment of Coral Server

# ==============================================================================
# Build Stage: Compile the Coral Server application
# ==============================================================================
FROM gradle:8.5-jdk21 AS build

# Set working directory
WORKDIR /app

# Clone the Coral Server repository
RUN git clone https://github.com/Coral-Protocol/coral-server.git .

# Build the application, skipping tests to speed up the build
RUN gradle build --no-daemon -x test

# Create configuration directory
RUN mkdir -p /coral-config

# Copy default configs if they exist, otherwise create minimal ones.
# Note: The server port here is set to 7860, but it will be overridden at runtime.
RUN if [ ! -f src/main/resources/application.yaml ]; then \
        echo "server:" > /coral-config/application.yaml && \
        echo "  port: 7860" >> /coral-config/application.yaml && \
        echo "mcp:" >> /coral-config/application.yaml && \
        echo "  transport: sse" >> /coral-config/application.yaml; \
    else \
        cp src/main/resources/application.yaml /coral-config/; \
    fi && \
    if [ ! -f src/main/resources/registry.toml ]; then \
        touch /coral-config/registry.toml; \
    else \
        cp src/main/resources/registry.toml /coral-config/; \
    fi

# ==============================================================================
# Runtime Stage: Set up the final container with Nginx and the Java app
# ==============================================================================
FROM openjdk:21-jdk-slim

# Install Nginx for reverse proxying
RUN apt-get update && apt-get install -y \
    curl \
    nginx \
    && rm -rf /var/lib/apt/lists/*

# Set working directory
WORKDIR /app

# Copy built application and configs from the build stage
COPY --from=build /app/build/libs/*.jar app.jar
COPY --from=build /coral-config /app/coral-config

# Create Nginx config to proxy requests from public port 7860 to the internal Coral Server port 5555
RUN echo 'server {' > /etc/nginx/sites-available/mcp-proxy && \
    echo '    listen 7860;' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '    server_name localhost;' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '    # Proxy all locations to the Coral Server' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '    location / {' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '        proxy_pass http://127.0.0.1:5555;' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '        proxy_http_version 1.1;' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '        proxy_set_header Upgrade $http_upgrade;' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '        proxy_set_header Connection "upgrade";' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '        proxy_set_header Host $host;' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '        proxy_cache_bypass $http_upgrade;' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '        proxy_buffering off;' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '        proxy_read_timeout 86400;' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '    }' >> /etc/nginx/sites-available/mcp-proxy && \
    echo '}' >> /etc/nginx/sites-available/mcp-proxy && \
    ln -s /etc/nginx/sites-available/mcp-proxy /etc/nginx/sites-enabled/ && \
    rm /etc/nginx/sites-enabled/default

# Create a startup script to run both Nginx and the Coral Server
RUN echo '#!/bin/bash' > /app/start.sh && \
    echo 'set -e' >> /app/start.sh && \
    echo '' >> /app/start.sh && \
    echo '# Start Nginx in the background, listening on port 7860' >> /app/start.sh && \
    echo 'nginx -g "daemon off;" &' >> /app/start.sh && \
    echo 'NGINX_PID=$!' >> /app/start.sh && \
    echo '' >> /app/start.sh && \
    echo '# Start Coral Server, telling it to listen on internal port 5555' >> /app/start.sh && \
    echo 'java -Xmx1g -Xms512m -jar app.jar --sse-server 5555 &' >> /app/start.sh && \
    echo 'CORAL_PID=$!' >> /app/start.sh && \
    echo '' >> /app/start.sh && \
    echo '# Wait for either process to exit' >> /app/start.sh && \
    echo 'wait -n $NGINX_PID $CORAL_PID' >> /app/start.sh && \
    echo '' >> /app/start.sh && \
    echo '# Clean up both processes if one exits' >> /app/start.sh && \
    echo 'kill $NGINX_PID $CORAL_PID 2>/dev/null || true' >> /app/start.sh && \
    chmod +x /app/start.sh

# Create a non-root user as required by Hugging Face Spaces
RUN useradd -m -u 1000 user && \
    chown -R user:user /app && \
    chown -R user:user /var/log/nginx && \
    chown -R user:user /var/lib/nginx && \
    touch /var/run/nginx.pid && \
    chown user:user /var/run/nginx.pid

USER user

# Set environment variables
ENV HOME=/home/user \
    PATH=/home/user/.local/bin:$PATH \
    CONFIG_PATH=/app/coral-config/

# Expose the public port that Nginx is listening on
EXPOSE 7860

# Health check to ensure the service is running and accessible via the proxy
HEALTHCHECK --interval=30s --timeout=10s --start-period=60s --retries=3 \
    CMD curl -f http://localhost:7860/devmode/exampleApplication/privkey/session1/sse || exit 1

# Start the application using the script
CMD ["/app/start.sh"]