logaste v4

结构化日志框架 — The modern structured Node.js logger.

Logaste: structured JSON logging with level control, sampling, context propagation, remote configuration, tamper-evident audit logging, and pluggable transports. Zero dependencies.

npm install logaste

Quick Start

const { createLogger, ConsoleTransport } = require('logaste')

const log = createLogger({
  transports: [new ConsoleTransport({ pretty: true })],
})

log.info('Server starting', { port: 3000 })
log.warn('Memory high', { usage: '85%' })
log.error('Connection failed', new Error('ECONNREFUSED'))

Audit Logging (v4)

Tamper-evident, hash-chained audit trail for compliance and security.

const { AuditLogger } = require('logaste')

const audit = new AuditLogger({
  name: 'financial-system',
  filename: '/var/log/audit.log',
})

// Record auditable events
audit.audit('USER_LOGIN', {
  actor: '[email protected]',
  target: 'system',
  metadata: { ip: '10.0.0.1', role: 'admin' },
})

audit.audit('FUNDS_TRANSFER', {
  actor: '[email protected]',
  target: 'account-xyz',
  metadata: { amount: 5000, currency: 'USD' },
})

await audit.flush()

Verification

const { AuditVerifier } = require('logaste')

const result = AuditVerifier.verify('/var/log/audit.log')
console.log('Audit log valid:', result.valid) // true/false
console.log('Entries:', result.entries)
console.log('Errors:', result.errors)

HMAC Signing

const audit = new AuditLogger({
  filename: '/var/log/audit.log',
  hmacKey: process.env.AUDIT_HMAC_KEY, // prevents forgery
})

// Verify with the same key
const result = AuditVerifier.verify('/var/log/audit.log', {
  hmacKey: process.env.AUDIT_HMAC_KEY,
})

Audit Entry Format

{
  "type": "audit",
  "timestamp": "2026-05-28T14:00:00.000Z",
  "logger": "financial-system",
  "event": "USER_LOGIN",
  "actor": "[email protected]",
  "target": "system",
  "metadata": { "ip": "10.0.0.1" },
  "seq": 1,
  "prevHash": "0000000000000000000000000000000000000000000000000000000000000000",
  "hash": "a1b2c3..."
}

Each entry is chained to the previous via prevHash. Optional HMAC field prevents forgery. AuditVerifier checks hash chain integrity, sequence order, and HMAC signatures.

Remote Configuration (v3)

const { RemoteConfig } = require('logaste')

RemoteConfig.url('https://config.example.com/logging.json', {
  pollInterval: 30000,
  loggers: [log],
}).start()

Sources: HTTP endpoint, local file, or custom async function.

Log Levels

trace(10) → debug(20) → info(30) → warn(40) → error(50) → fatal(60)

log.setLevel('debug')
log.isEnabled('warn')
log.log('warn', 'dynamic level')

Context & Child Loggers

log.withContext({ requestId: 'abc' })
const child = log.child({ userId: 42 })

Sampling

log.setSampler('debug', Sampler.rate(0.1))
log.setSampler('trace', Sampler.random(0.05))
log.setSampler('info', Sampler.hash(0.2))

Transports

| Transport | Description | |-----------|-------------| | ConsoleTransport | stdout/stderr, color, pretty-print | | FileTransport | file with size-based rotation | | HTTPTransport | POST to remote endpoint | | SyslogTransport | RFC 5424 over UDP/TCP |

API Reference

createLogger(options)

name, level, context, transports, formatter, batchSize, flushInterval, onError

Logger Methods

log(level, msg, meta?) · trace/debug/info/warn/error/fatal · child(fields) · setLevel(level) · setSampler(level, sampler) · isEnabled(level) · withContext(fields) · flush()

AuditLogger(options)

name · filename (or transport) · hmacKey · .audit(event, data) · .flush()

AuditVerifier.verify(filepath, options)

Returns { valid, entries, errors }

License

MIT