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Guccho uses environment variables for sensitive configuration like database credentials and API keys. This guide covers how to set up and use environment variables in your configuration files.

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Setting Up Environment Variables

Create a .env file in your project root by copying the example: 
cp .env.example .env
Then edit .env with your actual values: 
# Base URL for your site
NUXT_PUBLIC_BASE_URL=ppy.sb

# Database connection (required for bancho.py and ppy.sb@bancho.py)
DB_DSN=mysql://username:password@localhost:3306/database

# Redis connection (required if using redis session store)
REDIS_URL=redis://localhost

# Production deployment (optional)
# HOST=127.0.0.1
Never commit your .env file to version control! It should be listed in .gitignore.

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Environment Variable Functions

Guccho provides two utility functions for accessing environment variables in your configuration files:

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env() - Required Variables

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env(key)
function
Retrieves a required environment variable. If the variable is not set, Guccho will fail to start.Use this for:
  • Essential credentials like database connections
  • Required API keys
  • Any configuration that must be present
import { env } from './src/server/common/utils'

export default {
  dsn: env('DB_DSN'),  // Required - app won't start without it
}
The absence of a required variable will prevent Guccho from launching with a clear error message.

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safeEnv() - Optional Variables

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safeEnv(key)
function
Retrieves an optional environment variable. Returns undefined if not set.Use this for:
  • Optional configuration with sensible defaults
  • Feature flags
  • Non-critical settings
import { safeEnv } from './src/server/common/utils'

export default {
  // Falls back to localhost if REDIS_URL is not set
  redisURL: safeEnv('REDIS_URL') ?? 'redis://localhost',
}
Use the nullish coalescing operator (??) to provide default values when the variable is not set.

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Common Environment Variables

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Database Connection

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DB_DSN
string
required
MySQL database connection string.Format: mysql://username:password@host:port/databaseExample:
DB_DSN=mysql://guccho:secretpass@localhost:3306/gulag
Used in configuration:
dsn: env('DB_DSN')
This is required for both bancho.py and ppy.sb@bancho.py adapters.

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Redis Connection

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REDIS_URL
string
Redis server connection URL.Format: redis://host:portDefault: redis://localhostExample:
REDIS_URL=redis://localhost:6379
With authentication:
REDIS_URL=redis://:password@localhost:6379
Used in configuration:
redisURL: safeEnv('REDIS_URL') ?? 'redis://localhost'
Required if you set sessionStore: 'redis' in your backend configuration.

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Public Base URL

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NUXT_PUBLIC_BASE_URL
string
Public-facing base URL for your server. This is accessible in both server and client code.Example:
NUXT_PUBLIC_BASE_URL=ppy.sb
Variables prefixed with NUXT_PUBLIC_ are exposed to the client-side code. See Nuxt runtime config for details.

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Production Deployment

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HOST
string
IP address to bind the server to in production.Default: 0.0.0.0 (all interfaces)Example:
HOST=127.0.0.1
Use 127.0.0.1 to only accept local connections, or 0.0.0.0 to accept connections from any interface.

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Usage Examples

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Required Database Connection

import { env } from './src/server/common/utils'

export default {
  // Will throw error if DB_DSN is not set
  dsn: env('DB_DSN'),
}

# .env
DB_DSN=mysql://user:pass@localhost:3306/gulag

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Optional Redis with Fallback

import { safeEnv } from './src/server/common/utils'

export default {
  // Falls back to localhost if not set
  redisURL: safeEnv('REDIS_URL') ?? 'redis://localhost',
}

# .env
# Uncomment to override default
# REDIS_URL=redis://redis.example.com:6379

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Multiple Fallback Levels

import { safeEnv } from './src/server/common/utils'

export default {
  apiUrl: safeEnv('API_URL') ?? safeEnv('FALLBACK_API_URL') ?? 'http://localhost:3000',
}

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Backend Adapter Requirements

Required:
  • DB_DSN - MySQL database connection
Optional:
  • REDIS_URL - Redis connection (recommended for production)
# .env for bancho.py
DB_DSN=mysql://username:password@localhost:3306/database
REDIS_URL=redis://localhost

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Environment-Specific Configuration

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Development

# .env.development
DB_DSN=mysql://dev:dev@localhost:3306/gulag_dev
REDIS_URL=redis://localhost:6379
NUXT_PUBLIC_BASE_URL=localhost:3000

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Production

# .env.production
DB_DSN=mysql://prod_user:secure_password@db.example.com:3306/gulag_prod
REDIS_URL=redis://:redis_password@redis.example.com:6379
NUXT_PUBLIC_BASE_URL=ppy.sb
HOST=127.0.0.1
Use strong, unique passwords in production environments.

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Best Practices

1

Never commit secrets

Ensure .env is in your .gitignore file:
# .gitignore
.env
.env.local
.env.*.local
2

Use env() for required values

Required configuration should use env() to fail fast:
dsn: env('DB_DSN'),  // App won't start without this
3

Provide sensible defaults

Optional configuration should have defaults using safeEnv():
redisURL: safeEnv('REDIS_URL') ?? 'redis://localhost',
4

Document your variables

Keep .env.example updated with all required variables:
# Database (required)
DB_DSN=mysql://username:password@localhost:3306/database

# Redis (optional, defaults to localhost)
# REDIS_URL=redis://localhost

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Troubleshooting

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”env validation error”

If you see this error, a required environment variable is missing or invalid: 
env validation error:
DB_DSN is required
Solution: Check that all required variables are set in your .env file.

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Variables not loading

  1. Ensure .env is in the project root directory
  2. Restart the development server after changing .env
  3. Check for typos in variable names (they’re case-sensitive)

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Connection refused errors

If database or Redis connections fail:
  1. Verify the service is running: mysql or redis-cli
  2. Check the connection string format
  3. Ensure firewall rules allow connections
  4. Test credentials manually

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Next Steps

Backend Configuration

Use environment variables in backend config

UI Configuration

Configure UI settings and branding

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