Class MikroLog

Description

MikroLog is a Lambda-oriented lightweight JSON logger.

Example

// ES5 format
const { MikroLog } = require('mikrolog');
// ES6 format
import { MikroLog } from 'mikrolog';

const logger = MikroLog.start();

// String message
logger.log('Hello World!');

// Object message
logger.log({
 Hello: 'World!',
 statement: 'Objects work just as well!'
});

Properties

logBuffer

Methods

debug enrichNext error flushLogs info isDebugLogSampled log setCorrelationId setDebugSamplingRate setNestedValue setTransport warn enrich reset start

Properties

StaticlogBuffer

logBuffer: LogOutput[] = []

Methods

debug

  • debug(message: Message, httpStatusCode?: number): LogOutput

  • Parameters

    • message: Message
    • OptionalhttpStatusCode: number

    Returns LogOutput

    Description

    Output a DEBUG log. Message may be string or object. This will respect whatever sampling rate is currently set.

    Example

    logger.debug('My message!');

enrichNext

  • enrichNext(input: Record<string, any>): void

  • Parameters

    • input: Record<string, any>

    Returns void

    Description

    If you want a one-time root-level enrichment, you can do:

    const logger = MikroLog.start();
    logger.enrichNext({ someId: '123456789abcdefghi' });
    logger.info('Ping!'); // Enrichment is present on log
    logger.info('Ping!'); // Enrichment is no longer present

    You can also use nested objects:

    logger.enrichNext({ myObject: { myValue: 'Something here', otherValue: 'Something else' } });

error

flushLogs

  • flushLogs(): Promise<void>

  • Returns Promise<void>

    Description

    Flush ("send") logs to the external transport. Nothing happens if you don't have a transport or logs.

    To avoid doing this all the time and adding latency, simply run this at the end of your function invocation to send all buffered logs at once.

info

isDebugLogSampled

  • isDebugLogSampled(): boolean

  • Returns boolean

    Description

    Check if MikroLog has sampled the last log. Will only return true value after having output an actual DEBUG log.

log

setCorrelationId

  • setCorrelationId(correlationId: string): void

  • Parameters

    • correlationId: string

    Returns void

    Description

    Set correlation ID manually, for example for use in cross-boundary calls.

    This value will be propagated to all future logs.

setDebugSamplingRate

  • setDebugSamplingRate(samplingPercent: number): number

  • Parameters

    • samplingPercent: number

    Returns number

    Description

    Set sampling rate of DEBUG logs.

setNestedValue

  • setNestedValue(target: any, path: string[], key: string, value: any): void

  • Utility function to set a nested value in an object.

    Parameters

    • target: any
    • path: string[]
    • key: string
    • value: any

    Returns void

setTransport

  • setTransport(transport: Transport): void

  • Parameters

    Returns void

    Description

    Set a custom transport.

    Example

    const transport = new AxiomTransport({
      auth: process.env.AXIOM_API_KEY,
      dataset: 'my_dataset'
    });
    logger.setTransport(transport);

warn

Staticenrich

Staticreset

  • reset(): void

  • Returns void

    Description

    An emergency mechanism if you absolutely need to reset the instance to its empty default state.

Staticstart

  • start(input?: MikroLogInput): MikroLog

  • Parameters

    Returns MikroLog

    Description

    This instantiates MikroLog. In order to be able to "remember" event and context we use a singleton pattern to reuse the same logical instance.

    If the start method receives any input, that input will overwrite any existing metadata, event, and context.

    It will also, consequently, wipe the Lambda cold start state.

    If you want to "add" to these, you should instead call enrich() and pass in your additional data there.

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