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Logging

Log messages in Bigsby are produced in a structured JSON format. Noise is kept to a minimum by default, limited to the incoming request path and outgoing response status code. Logging behaviour can be customized using configuration or using an environment variable. By default, logging is enabled and set to the info log level.

Levels​

Supported log levels:

  • debug: verbose debugging information.
  • info: light incoming/outgoing message metadata.
  • warn: notable events that won't result in the pre-mature termination of the request execution lifecycle, but should be addressed.
  • error: events that result in the pre-mature termination of the request execution lifecycle.

Environment variable​

Logging behaviour can be defined using the BIGSBY_LOG environment variable. Configuration set at this level will override configurations provided to the Bigsby instance.

A comma separated string of instance names and log levels is parsed at runtime to determine behaviour (a Bigsby instance can be given a name at the point of instantiation as a constructor argument).

// "{instanceName}={logLevel},{instanceName}={logLevel}"
process.env.BIGSBY_LOG="bigsby=info,myapp=error";

A wildcard * can be specified to turn logging on at the debug level for all instances.

process.env.BIGSBY_LOG="*";
info

The default instance name is bigsby, which increments to bigsby(1), bigsby(2) etc. if multiple un-named instances are created.

Bigsby configuration​

Logging config can be defined when creating a Bigsby instance, as per below.

const bigsby = new Bigsby(
  {
    logging: {
      enabled: true,
      level: LogLevel.INFO,
    }
  }
);

Logger override​

It's possible to BYO logger by providing an object or class which implements the BigsbyLogger interface. If your chosen logger doesn't fit this interface out of the box, it's recommended to write adapter function.

const loggerAdapter: BigsbyLogger = {
  info: (msg: string, ...meta: any[]) => myLogger.info(msg), // <- transform inputs here to desired format
  // ... other methods
}


const bigsby = new Bigsby(
  {
    logging: {
      logger: loggerAdapter
    }
  }
);