Fastify

ByteHide Logger integrates with Fastify applications through plugins and request/response hooks for comprehensive logging.

Installation

npm install @bytehide/logger fastify

Basic Setup

const fastify = require('fastify')({ logger: false });
const { Log } = require('@bytehide/logger');

// Configure logger
Log.configure({
    projectToken: process.env.BYTEHIDE_PROJECT_TOKEN,
    logLevel: 'info'
});

// Start server
const start = async () => {
    try {
        await fastify.listen({ port: 3000 });
        Log.info('Fastify server started', {
            context: { port: 3000 }
        });
    } catch (error) {
        Log.error('Failed to start server', {}, error);
        process.exit(1);
    }
};

start();

Logger Plugin

// plugins/logger.js
const { Log } = require('@bytehide/logger');

async function loggerPlugin(fastify, options) {
    Log.configure({
        projectToken: options.projectToken,
        logLevel: options.logLevel || 'info'
    });
    
    // Add logger to fastify instance
    fastify.decorate('log', Log);
    
    Log.info('ByteHide logger plugin registered');
}

module.exports = loggerPlugin;

Register Plugin

const fastify = require('fastify')();

// Register logger plugin
fastify.register(require('./plugins/logger'), {
    projectToken: process.env.BYTEHIDE_PROJECT_TOKEN,
    logLevel: 'info'
});

Request Logging Hooks

// Log all requests
fastify.addHook('onRequest', async (request, reply) => {
    fastify.log.info('Request received', {
        context: {
            method: request.method,
            url: request.url,
            userAgent: request.headers['user-agent'],
            ip: request.ip
        }
    });
});

// Log responses
fastify.addHook('onSend', async (request, reply, payload) => {
    fastify.log.info('Response sent', {
        context: {
            method: request.method,
            url: request.url,
            statusCode: reply.statusCode
        }
    });
});

Route Handlers

// GET route with logging
fastify.get('/api/users', async (request, reply) => {
    fastify.log.info('Fetching users');
    
    try {
        const users = await getUsersFromDatabase();
        
        fastify.log.info('Users fetched successfully', {
            context: { count: users.length }
        });
        
        return users;
    } catch (error) {
        fastify.log.error('Failed to fetch users', {
            context: { endpoint: '/api/users' }
        }, error);
        
        reply.status(500).send({ error: 'Internal server error' });
    }
});

// POST route with logging
fastify.post('/api/users', async (request, reply) => {
    fastify.log.info('Creating user', {
        context: { email: request.body.email }
    });
    
    try {
        const user = await createUser(request.body);
        
        fastify.log.info('User created successfully', {
            context: { userId: user.id }
        });
        
        return user;
    } catch (error) {
        fastify.log.error('Failed to create user', {
            context: { email: request.body.email }
        }, error);
        
        reply.status(400).send({ error: 'Failed to create user' });
    }
});

Error Handling

// Global error handler
fastify.setErrorHandler((error, request, reply) => {
    fastify.log.error('Unhandled error', {
        context: {
            method: request.method,
            url: request.url,
            statusCode: reply.statusCode
        }
    }, error);
    
    reply.status(500).send({ error: 'Internal server error' });
});

User Identification

// Authentication hook
fastify.addHook('preHandler', async (request, reply) => {
    if (request.user) {
        fastify.log.identify(request.user.id, request.user.email);
    }
});

Best Practices