Logging

Overview

ElyOS uses its own logging system that can write to multiple targets simultaneously (console, file, database). Logs can be viewed in the built-in Log application.

Importing Logger

import { logger } from '$lib/server/logging';

Logging Levels

logger.debug('Detailed debug information', { extra: 'data' });
logger.info('General information');
logger.warn('Warning', { context: 'something' });
logger.error('An error occurred', { error: err });
logger.fatal('Critical error', { error: err });

Structured Logging

The logger accepts structured data as a second parameter:

logger.info('User logged in', {
  userId: user.id,
  email: user.email,
  ip: event.getClientAddress()
});

logger.error('Database error', {
  operation: 'findUser',
  userId: id,
  error: error.message
});

Logging in Server Actions

import { command, getRequestEvent } from '$app/server';
import { logger } from '$lib/server/logging';

export const myAction = command(schema, async (input) => {
  const { locals } = getRequestEvent();

  logger.info('Action executed', {
    action: 'myAction',
    userId: locals.user?.id,
    input
  });

  try {
    // ... logic
    return { success: true };
  } catch (error) {
    logger.error('Action failed', {
      action: 'myAction',
      error: error instanceof Error ? error.message : String(error)
    });
    return { success: false, error: 'Internal error' };
  }
});

Configuration

Logging is configured in the .env file:

Variable	Default	Description
LOG_TARGETS	console	Comma-separated targets: console, file, database
LOG_LEVEL	error	Minimum level: debug, info, warn, error, fatal
LOG_DIR	./logs	Log files directory (if file target active)

Development Configuration

LOG_TARGETS=console
LOG_LEVEL=debug

Production Configuration

LOG_TARGETS=console,database
LOG_LEVEL=info

Log Application

The built-in Log application (src/apps/log/) displays logs saved to the database. Accessible only with admin permissions.

Logs are stored in the error_logs table when the database target is active.

Client-Side Error Logging

Client-side JavaScript errors are automatically logged via the /api/log endpoint. This is configured in hooks.client.ts.