Library: Logger

We use @graphile/logger as a log abstraction so that you can log to whatever logging facilities you like. By default this will log to console, and debug-level messages are not output unless you have the environmental variable GRAPHILE_LOGGER_DEBUG=1. You can override this by passing a custom logger.

It's recommended that your tasks always use the methods on helpers.logger for logging so that you can later route your messages to a different log store if you want to. There are 4 methods, one for each level of severity (error, warn, info, debug), and each accept a string as the first argument and optionally an arbitrary object as the second argument:

• helpers.logger.error(message: string, meta?: LogMeta)
• helpers.logger.warn(message: string, meta?: LogMeta)
• helpers.logger.info(message: string, meta?: LogMeta)
• helpers.logger.debug(message: string, meta?: LogMeta)

You may customize where log messages from graphile-worker (and your tasks) go by supplying a custom Logger instance using your own logFactory.

const { Logger, run } = require("graphile-worker");

/* Replace this function with your own implementation */
function logFactory(scope) {
  return (level, message, meta) => {
    console.log(level, message, scope, meta);
  };
}

const logger = new Logger(logFactory);

// Pass the logger to the 'run' method as part of options:
run({
  logger,
  /* pgPool, taskList, etc... */
});

Your logFactory function will be passed a scope object which may contain the following keys (all optional):

• label (string): a rough description of the type of action (‘worker’ and ‘job’ are the currently used values).
• workerId (string): the ID of the worker instance
• taskIdentifier (string): the task name (identifier) of the running job
• jobId (number): the id of the running job

And it should return a logger function which will receive these three arguments:

• level (‘error’, ‘warning’, ‘info’ or ‘debug’) — severity of the log message
• message (string) — the log message itself
• meta (optional object) — may contain other useful metadata, useful in structured logging systems

The return result of the logger function is currently ignored; but we strongly recommend that for future compatibility you do not return anything from your logger function.

See the @graphile/logger documentation for more information.

note

You do not need to (and should not) customize, inherit or extend the Logger class at all.

note

Some log messages are gated behind the GRAPHILE_ENABLE_DANGEROUS_LOGS=1 environmental variable — to see them you will need to enable that envvar AND enable debug logging (e.g. with GRAPHILE_LOGGER_DEBUG=1 as mentioned above) — do not do this in production as these logs may include incredibly sensitive details such as your full database connection string including password.