Logging

NodeC logs through pino, wrapped in a NestJS LoggerService. The framework logs the real reason for most failures the API deliberately hides - why a login failed, which permission check denied a request, which database error happened - so the log is the first place to look when a request doesn't do what you expect.

@Module({
  imports: [
    ConfigProviderModule.register(AppModuleBase.configProviderModuleRegisterOptions),
    LoggerModule.register(), // the default params: logs/app_logs.txt + pretty output on stdout
    // ...
  ]
})
export class AppModule extends AppModuleBase {}

Then inject it anywhere:

constructor(protected logger: LoggerService) {}

this.logger.info('Task created.', { taskId: task.id });
this.logger.error('Could not reach the payment provider:', err);

Options

LoggerModule.register({ pinoParams? }) takes the full nestjs-pino params - they replace the defaults rather than being merged with them. To change one setting, spread DEFAULT_PINO_PARAMS:

LoggerModule.register({
  pinoParams: {
    ...DEFAULT_PINO_PARAMS,
    pinoHttp: {
      ...DEFAULT_PINO_PARAMS.pinoHttp,
      transport: {
        targets: [
          { target: 'pino/file', options: { destination: `logs/app_logs_${process.env.NODE_ENV}.txt`, mkdir: true } },
          { target: 'pino-pretty', options: { destination: 1 } }
        ]
      }
    }
  } as Params
})

DEFAULT_PINO_PARAMS:

• writes JSON lines to logs/app_logs.txt (the folder is created if it's missing) and pretty-prints to stdout
• gives every request a UUID request id (reqId in the JSON lines)
• logs requests and responses quietly (quietReqLogger, quietResLogger)

What the framework logs

Source	Example
HTTPRequestLoggingMiddleware	[tasks]: GET /tasks for every request
Authorization middleware	Missing authorization token., AUTH_INVALID
Access control	[coursePlatform][HTTPAccessControlInterceptor]: No user access to resource coursePlatform.<context>.<resource> - FGA_NO_ACCESS.
Authentication	[Domain.iam.AuthenticationManager][userLocal]: Login attempt failed ...
Error interceptor	every error thrown by a handler, with its stack
Data modules	connection attempts and failures

TIP

The JSON log lines carry the request id, so you can follow one request through every component with grep <reqId> logs/app_logs.txt.

---

Previous: Configuration · Next: Multiple data services