pino-std-serializers

What is pino-std-serializers?

The pino-std-serializers package provides standard serializers for the Pino logging library. These serializers help in formatting various types of JavaScript objects and values into a more structured and readable format for logging purposes. This is particularly useful in applications where consistent log formats are necessary for debugging and monitoring.

What are pino-std-serializers's main functionalities?

req (HTTP request serializer)

Serializes HTTP request objects to log them in a structured format, including method, url, headers, and other relevant information.

const pino = require('pino');
const stdSerializers = require('pino-std-serializers');
const logger = pino({
  serializers: {
    req: stdSerializers.req
  }
});

http.createServer((req, res) => {
  logger.info({req}, 'request received');
  res.end('hello world');
}).listen(3000);

res (HTTP response serializer)

Serializes HTTP response objects to capture and log status code, headers, and other response attributes.

const pino = require('pino');
const stdSerializers = require('pino-std-serializers');
const logger = pino({
  serializers: {
    res: stdSerializers.res
  }
});

http.createServer((req, res) => {
  res.on('finish', () => {
    logger.info({res}, 'response sent');
  });
  res.end('hello world');
}).listen(3000);

err (Error serializer)

Provides a way to serialize error objects, including the message, stack trace, and other properties, which aids in debugging and error tracking.

const pino = require('pino');
const stdSerializers = require('pino-std-serializers');
const logger = pino({
  serializers: {
    err: stdSerializers.err
  }
});

try {
  throw new Error('Something went wrong');
} catch (err) {
  logger.error({err}, 'error occurred');
}

Other packages similar to pino-std-serializers

morgan-json

While not a direct serializer library, morgan-json provides middleware to format HTTP request logs into JSON using Morgan, which can be seen as an alternative approach to logging HTTP requests compared to using pino-std-serializers with Pino.

README

pino-std-serializers

This module provides a set of standard object serializers for the Pino logger.

Serializers

exports.err(error)

Serializes an Error like object. Returns an object:

{
  type: 'string', // The name of the object's constructor.
  message: 'string', // The supplied error message.
  stack: 'string' // The stack when the error was generated.
}

Any other extra properties, e.g. statusCode, that have been attached to the object will also be present on the serialized object.

exports.mapHttpResponse(response)

Used internally by Pino for general response logging. Returns an object:

{
  res: {}
}

Where res is the response as serialized by the standard response serializer.

exports.mapHttpRequest(request)

Used internall by Pino for general request logging. Returns an object:

{
  req: {}
}

Where req is the request as serialized by the standard request serializer.

exports.req(request)

The default request serializer. Returns and object:

{
  id: 'string', // Defaults to `undefined`, unless there is an `id` property 
                // already attached to the `request` object or to the `request.info`
                // object. Attach a synchronous function
                // to the `request.id` that returns an identifier to have
                // the value filled.
  method: 'string',
  url: 'string', // the request pathname (as per req.url in core HTTP)
  headers: Object,
  remoteAddress: 'string',
  remotePort: Number,
  raw: Object // Non-enumerable, i.e. will not be in the output, original
              // request object. This is available for subsequent serializers
              // to use. In cases where the `request` input already has 
              // a `raw` property this will be `request.raw` instead of the original 
              // request 
}

exports.res(response)

The default response serializer. Returns an object:

{
  statusCode: Number,
  headers: Object, // The headers to be sent in the response.
  raw: Object // Non-enumerable, i.e. will not be in the output, original
              // response object. This is available for subsequent serializers
              // to use.
}

exports.wrapRequestSerializer(customSerializer)

A utility method for wrapping the default request serializer. This allows custom serializers to work with the already serialized object.

The customSerializer accepts one parameter: the newly serialized request object.

exports.wrapResponseSerializer(customSerializer)

A utility method for wrapping the default response serializer. This allows custom serializers to work with the already serialized object.

The customSerializer accepts one parameter: the newly serialized response object.

License

MIT License