import type { Context, Next } from 'hono';
import { getClientInfo } from '../utils/clientInfo.js';
import { logger } from '../utils/logger.js';
import { formatMemoryUsage, getMemoryUsage } from '../utils/memory.js';
import { calculateLatency } from '../utils/time.js';
// Augment Hono's context type
declare module 'hono' {
interface ContextVariableMap {
requestId: string;
}
}
// Generate unique request identifier
function generateRequestId(): string {
return `req-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
}
// Extract trace context from Cloud Run's X-Cloud-Trace-Context header
// Format: TRACE_ID/SPAN_ID;o=TRACE_TRUE
function extractTraceContext(c: Context): { trace?: string; spanId?: string } {
const traceHeader = c.req.header('x-cloud-trace-context');
if (!traceHeader) return {};
const projectId = process.env.GOOGLE_CLOUD_PROJECT || process.env.GCP_PROJECT;
const [traceSpan] = traceHeader.split(';');
const [traceId, spanId] = traceSpan.split('/');
if (!traceId) return {};
return {
trace: projectId ? `projects/${projectId}/traces/${traceId}` : traceId,
spanId,
};
}
// Main logging middleware for Hono
export function cloudLoggerMiddleware() {
return async function cloudLoggerMiddleware(c: Context, next: Next) {
const requestId = generateRequestId();
const startTime = Date.now();
// Add request ID to context for tracking
c.set('requestId', requestId);
// Collect basic request information
const method = c.req.method;
const url = new URL(c.req.url);
const clientInfo = getClientInfo(c);
// Extract trace context for Cloud Run distributed tracing
const traceContext = extractTraceContext(c);
// Log request start
logger.info({
message: `${method} ${url.pathname} started`,
requestId,
// Cloud Logging trace correlation field
...(traceContext.trace && { 'logging.googleapis.com/trace': traceContext.trace }),
...(traceContext.spanId && { 'logging.googleapis.com/spanId': traceContext.spanId }),
httpRequest: {
requestMethod: method,
requestUrl: url.toString(),
userAgent: clientInfo.userAgent,
referer: clientInfo.referer,
remoteIp: clientInfo.ip,
},
});
try {
// Execute the request
await next();
// Calculate response time and memory usage
const responseTime = calculateLatency(startTime);
const memoryUsage = getMemoryUsage();
// Log successful request completion
logger.info({
message: `${method} ${url.pathname} completed`,
requestId,
...(traceContext.trace && { 'logging.googleapis.com/trace': traceContext.trace }),
...(traceContext.spanId && { 'logging.googleapis.com/spanId': traceContext.spanId }),
httpRequest: {
requestMethod: method,
requestUrl: url.toString(),
status: c.res.status,
responseSize: c.res.headers.get('content-length'),
latency: responseTime,
userAgent: clientInfo.userAgent,
referer: clientInfo.referer,
remoteIp: clientInfo.ip,
},
memoryUsage: formatMemoryUsage(memoryUsage),
});
} catch (error) {
// Calculate response time even for errors
const responseTime = calculateLatency(startTime);
const memoryUsage = getMemoryUsage();
// Log error with context
logger.error({
message: `${method} ${url.pathname} failed`,
requestId,
...(traceContext.trace && { 'logging.googleapis.com/trace': traceContext.trace }),
...(traceContext.spanId && { 'logging.googleapis.com/spanId': traceContext.spanId }),
error: {
message: error instanceof Error ? error.message : 'Unknown error',
stack: error instanceof Error ? error.stack : undefined,
},
httpRequest: {
requestMethod: method,
requestUrl: url.toString(),
latency: responseTime,
userAgent: clientInfo.userAgent,
referer: clientInfo.referer,
remoteIp: clientInfo.ip,
},
memoryUsage: formatMemoryUsage(memoryUsage),
});
// Re-throw the error to be handled by Hono's error handler
throw error;
}
};
}
