azify-logger-client-v2/store.js

Azify Logger Client - Centralized logging for OpenSearch

const { AsyncLocalStorage } = require('async_hooks')

const als = new AsyncLocalStorage()

function generateId(bytes = 16) {
  return require('crypto').randomBytes(bytes).toString('hex')
}

function toTraceId(hex32) {
  // ensure 32 hex chars
  const h = (hex32 || '').padStart(32, '0').slice(0, 32)
  return `${h.substring(0, 8)}-${h.substring(8, 12)}-${h.substring(12, 16)}-${h.substring(16, 20)}-${h.substring(20, 32)}`
}

function startRequestContext(initial = {}) {
  const traceHex = initial.traceHex || generateId(16) // 16 bytes -> 32 hex
  const spanHex = initial.spanHex || generateId(8)    // 8 bytes -> 16 hex
  const ctx = {
    traceId: toTraceId(traceHex),
    spanId: spanHex,
    parentSpanId: initial.parentSpanId || null,
    requestId: initial.requestId
  }
  return ctx
}

function runWithRequestContext(ctx, fn) {
  return als.run(ctx, fn)
}

function getRequestContext() {
  return als.getStore() || null
}

module.exports = {
  als,
  startRequestContext,
  runWithRequestContext,
  getRequestContext
}