Setting the log levels using ConfigService

[fmagno]

How can I set the allowed log levels by using the ConfigService?

I tried to do it through main.ts but the logLevels are set during the app creation call which is also required to get the ConfigService.

const app = await NestFactory.create(
    AppModule.register(),
    { logger: configService.get('LOG_LEVELS') }    // <-- at this point I still can't do: const configService = app.get(ConfigService);
);

Is is possible to create the app object with the logLevels set to default and then override it? Something like this:

const app = await NestFactory.create(
    AppModule.register(),
    { logger: true }
);

const configService = app.get('ConfigService');
app.setLogLevels(configService.get('LOG_LEVELS'));

Also tried a different avenue but the solution is not ideal. I tried first to set the logLevels in the constructor of MyLogger but the class member logLevels is private to Logger so I can't override it. The same seems to be the case for the method isLogLevelEnabled(level).

The only option I found so far is to check the logLevels allowed inside the actual logging methods: log, warn, error, etc...

@Injectable()
export class MyLogger extends Logger {
    constructor(private configService: ConfigService) {
        super();
        MyLogger.logLevels = configService.get('LOG_LEVELS')   // <-- can't set because it's private to Logger
    }

    isLogLevelEnabled(level) {}   // <-- can't override because it's private to Logger


    log(message: any, context? string): void {
        const logLevels = this.configService.get('LOG_LEVELS');
        // check if this method has the right level to log the message depending on logLevels before proceeding
        super.log(message, context);
    }
}

Is there a better way to do this?

[kamilmysliwiec]

Please, use our Discord channel (support) for such questions. We are using GitHub to track bugs, feature requests, and potential improvements.

[fmagno]

Okay, cheers!

Just so it doesn't get lost in discord messages, this question relates to these issues: #6349 and #2343.