Integration with winston JSON

[aniketkalamkar]

I am not able to read the rtracer.id() in the winston logger config file and set the value as separate attribute in the json log. Can someone please help if the similar is implemented with sample piece of code. Thanks

[puzpuzpuz]

@aniketkalamkar could you provide sample code for what you're trying to achieve? I'm not sure if I understand the question.

[puzpuzpuz]

Closing due to inactivity. Please comment if you have an update here.

[pyrho]

I think the best way to achieve what OP wants is to create a dynamic getter in the log metadata (as explained here):

import * as rTracer from 'cls-rtracer';
import winston, { format } from 'winston';
const { combine, timestamp } = format;

export const Logger = (() => {
    const logger: winston.Logger = winston.createLogger({
        level: 'silly',
        format: combine(timestamp(), winston.format.json()),
        defaultMeta: {
            get requestId() { // This will run each time a log function is called
                return rTracer.id();
            },
        },
        transports: [new winston.transports.Console()],
    });
    return logger;
})();

example log output:

{
   "message":"a message",
   "level":"debug",
   "requestId":"92706940-070a-11eb-87e1-09ce93f1c9e4",
   "timestamp":"2020-10-05T12:59:15.302Z"
}

[puzpuzpuz]

Thanks for the update @pyrho!