How to disable debug console output generated by winston elasticstack client and transport?

Question

I'm using winston v3.2.1, winston-elasticsearch v0.8.8 and @elastic/elasticsearch v7.6.1 to push log entries for my NodeJS services to an Elastic Search cluster v7.6.2.

My logger is constructed as follows (see https://github.com/vanthome/winston-elasticsearch and https://www.npmjs.com/package/@elastic/elasticsearch):

import { Client } from '@elastic/elasticsearch';
import winston, { Logger } from 'winston';
import { ElasticsearchTransport } from 'winston-elasticsearch';
import { ELASTIC_HOST, ELASTIC_PORT, LOG_LEVEL } from './environment';
...
        this.logger = winston.createLogger({
            transports: [
                new ElasticsearchTransport({
                    client: new Client({
                        node: `http://${ELASTIC_HOST}:${ELASTIC_PORT}`
                    }),
                    index: 'sector',
                    level: LOG_LEVEL // Events I log that are 'info' or worse will be transported.
                })
            ]
        });

I then log using the logger reference directly:

this.logger.info(`Kill signal received: ${signal}`);

I can see that my log entries are being pushed to the Elastic Search cluster but the console logs are flooded with debug output from the elasticsearch and winston:elasticsearch loggers. I think they belong to the Elastic Node client and Elasticsearch Transport implementations.

2020-05-12T22:10:10.114Z elasticsearch Nothing to resurrect
...
2020-05-12T22:10:10.116Z winston:elasticsearch starting bulk writer
...
2020-05-12T22:10:18.122Z winston:elasticsearch nothing to flush
2020-05-12T22:10:20.123Z winston:elasticsearch tick
2020-05-12T22:10:20.123Z winston:elasticsearch nothing to flush

My services run inside Docker containers and I don't want the Docker logs to flood with debug noise. I tried to set the transport levels to error and even removing the Console transport completely but the debug noise persists. I tried the following to suppress the console output without much luck:

winston.level = 'error';
winston.transports.Console.level = 'error';
winston.transports.Console.silent = true;
this.logger.remove(winston.transports.Console);
winston.remove(winston.transports.Console);

I found a couple of threads on the subject but no luck:

It's almost like the client and transporter is using a separate logging mechanism.

Any suggestions?

score 1 · Answer 1 · answered May 13 '20 at 17:36

I've confirmed that the output was not generated by winston at all. That's why I couldn't disable it using the approaches I listed above.

It looks like the ElasticsearchTransport implementation uses a package called debug. It turns on when a pattern is specified in the DEBUG environment variable. I had it set to DEBUG=* so that I could see Express output. The debug noise stopped when I removed the environment variable.

If you see debug noise in your console, check that the debug package is not the cause. Many packages appear to use it.

How to disable debug console output generated by winston elasticstack client and transport?

1 Answers1