Logger

Structured logging backed by pino with configurable sinks.

Setup

The Logger reads its configuration from config/logging.ts:

// config/logging.ts
export default {
  level: 'info',
  sinks: {
    console: { enabled: true, level: 'debug' },
    file: { enabled: true, level: 'info', path: 'storage/logs/app.log' },
  },
}

Each sink runs independently — it can have its own minimum log level. The global level sets the floor for the pino instance.

Usage

The Logger is injectable and provides six log levels.

Using a service provider (recommended)

import { LoggerProvider } from '@strav/kernel'

app.use(new LoggerProvider())

The LoggerProvider registers Logger as a singleton. It depends on the config provider.

Manual setup

import { Logger } from '@strav/kernel'

app.singleton(Logger)
const logger = app.resolve(Logger)

Log methods

logger.trace('entering function', { fn: 'processOrder' })
logger.debug('cache miss', { key: 'user:42' })
logger.info('server started', { port: 3000 })
logger.warn('rate limit approaching', { current: 95, max: 100 })
logger.error('request failed', { statusCode: 500, path: '/api/users' })
logger.fatal('database unreachable', { host: 'db.example.com' })

Every method accepts an optional context object that gets merged into the structured JSON output.

Sinks

ConsoleSink

Outputs to stdout using pino-pretty for human-readable development logs.

{ enabled: true, level: 'debug' }

FileSink

Writes JSON-formatted log entries to a file. Automatically creates parent directories.

{ enabled: true, level: 'info', path: 'storage/logs/app.log' }

Custom sinks

Extend the LogSink base class and register it in the sink registry inside logger.ts:

import { LogSink, type SinkConfig } from '@strav/kernel'

class CustomSink extends LogSink {
  createStream() {
    // return a writable stream
  }
}

Log output

Logs are JSON-formatted (pino default). Each entry includes a timestamp, level, message, and any context fields:

{"level":30,"time":1707753600000,"msg":"server started","port":3000}

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