Configuration

PFP Checker uses environment variables for configuration. This page documents all available configuration options and best practices.

Configuration File

All configuration is managed through a .env file in the project root. The bot loads this file at startup using the dotenvy library.

Create your .env file by copying the example:

cp .env.example .env

Environment Variables

The following environment variables are used by PFP Checker (defined in src/util/config.rs):

DISCORD_TOKEN

string

required

Your Discord bot token for authentication with the Discord API.How to get it:

Go to the Discord Developer Portal
Create a new application or select an existing one
Navigate to the “Bot” section
Click “Reset Token” or “Copy” to get your token

Keep this token secret! Never commit it to version control or share it publicly.

Example:

DISCORD_TOKEN=MTExMjIzMzQ0NTU2Njc3ODg5.GaBcDe.FgHiJkLmNoPqRsTuVwXyZ1234567890abc

IMGBB_KEY

string

required

Your ImgBB API key for uploading and hosting profile pictures and server icons.How to get it:

Go to ImgBB API
Sign up or log in
Generate an API key from your account settings

ImgBB provides free image hosting with API access. The bot uses this service to archive profile pictures and server icons.

Example:

IMGBB_KEY=a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6

DATABASE_URL

string

required

SQLite database file path or connection URL.Format: sqlite:<path-to-database-file>

The database file will be created automatically if it doesn’t exist (via create_if_missing: true in src/db/connection.rs:12).

Examples:

DATABASE_URL=sqlite:database.sqlite

Example Configuration

Here’s the complete .env.example file from the repository:

.env.example

DISCORD_TOKEN=<token>
IMGBB_KEY=<key>
DATABASE_URL=sqlite:database.sqlite

Configuration Loading

The configuration is loaded in src/util/config.rs using the following structure:

src/util/config.rs

use dotenvy::dotenv;
use std::env;

pub struct Config {
    pub discord_token: String,
    pub database_url: String,
    pub imgbb_key: String,
}

impl Config {
    pub fn from_env() -> Result<Self, env::VarError> {
        dotenv().ok();

        Ok(Config {
            discord_token: env::var("DISCORD_TOKEN")?,
            database_url: env::var("DATABASE_URL")?,
            imgbb_key: env::var("IMGBB_KEY")?,
        })
    }
}

All three environment variables are required. The bot will fail to start if any are missing.

Discord Bot Setup

To configure your Discord bot properly, follow these steps:

Create a Discord Application

Go to the Discord Developer Portal
Click “New Application”
Give your application a name (e.g., “PFP Checker”)

Create a Bot User

Navigate to the “Bot” section in the left sidebar
Click “Add Bot”
Confirm by clicking “Yes, do it!”
Copy your bot token and save it securely

Configure Bot Permissions

The bot requires the following permissions:

Read Messages/View Channels: To see commands
Send Messages: To respond to commands
Embed Links: To send rich embeds with profile picture history
Attach Files: To send image attachments
Read Message History: To process interactions

The bot uses Gateway Intents: None (as defined in src/main.rs:379). It relies solely on slash commands and doesn’t need message content or presence intents.

Generate Invite Link

Go to the “OAuth2” → “URL Generator” section
Select scopes: bot and applications.commands
Select the permissions listed above
Copy the generated URL and use it to invite the bot to your server

ImgBB API Setup

Create an ImgBB Account

Visit ImgBB and sign up for a free account.

Get Your API Key

Go to ImgBB API
Navigate to “Get API Key” or your account settings
Generate a new API key
Copy the key and add it to your .env file

Free Tier Limits: ImgBB’s free tier allows unlimited image uploads with a reasonable rate limit. The bot uses ImgBB to permanently archive profile pictures and server icons.

Database Configuration

Local Development

For local development, use a relative path:

.env

DATABASE_URL=sqlite:database.sqlite

This creates database.sqlite in the project root directory.

Docker Deployment

For Docker, the database is stored in a volume:

.env

DATABASE_URL=sqlite:/app/data/database.sqlite

The ./data directory on your host is mounted to /app/data inside the container, ensuring persistence.

Production Deployment

For production systems, use an absolute path:

.env

DATABASE_URL=sqlite:/var/lib/pfp-checker/database.sqlite

Ensure the directory exists and has proper permissions:

sudo mkdir -p /var/lib/pfp-checker
sudo chown your-username:your-username /var/lib/pfp-checker
sudo chmod 755 /var/lib/pfp-checker

Database Connection Pool

The bot uses SQLx connection pooling (configured in src/db/connection.rs):

src/db/connection.rs

pub async fn establish_connection(database_url: &str) -> Result<Arc<Pool<Sqlite>>, sqlx::Error> {
    // Create a connection pool
    let pool = SqlitePoolOptions::new()
        .max_connections(5)
        .connect_with(
            SqliteConnectOptions::new()
                .filename(database_url)
                .create_if_missing(true),
        )
        .await?;

    // Run migrations
    sqlx::migrate!("./migrations").run(&pool).await?;

    Ok(Arc::new(pool))
}

Connection Pool

Maximum of 5 concurrent database connections for optimal performance

Auto-creation

Database file is created automatically if it doesn’t exist

Auto-migrations

Migrations run automatically on every startup

Thread-safe

Uses Arc<Pool> for safe sharing across async tasks

Security Best Practices

Never commit secrets to version control! Always add .env to your .gitignore file.

Protecting Your Credentials

Never commit .env files
.gitignore
```
.env
.env.local
.env.*.local
```
Use environment-specific files
- .env.example - Template with placeholder values (safe to commit)
- .env - Actual credentials (never commit)
- .env.production - Production credentials (never commit)
Rotate tokens regularly
- Regenerate your Discord bot token periodically
- Update ImgBB API keys if compromised
Use restricted permissions
- Only grant the Discord permissions your bot actually needs
- Use separate API keys for development and production

Secure file permissions

chmod 600 .env  # Only owner can read/write

Environment-Specific Configuration

For different environments, you can use separate env files:

# .env.development
DISCORD_TOKEN=your_dev_token
IMGBB_KEY=your_dev_key
DATABASE_URL=sqlite:dev_database.sqlite

Load the appropriate file based on your environment:

# Development
ln -sf .env.development .env

# Production
ln -sf .env.production .env

Validation and Error Handling

The bot validates configuration at startup (src/main.rs:370):

src/main.rs

let config = Config::from_env().expect("Failed to load configuration.");

If any required environment variable is missing, the bot will:

Print an error message
Exit with a panic
Not start the Discord connection

Check the logs if the bot fails to start. Common issues include:

Missing .env file
Typos in environment variable names
Invalid token formats
Database permission errors

Troubleshooting

Failed to load configuration

Ensure your .env file exists and contains all required variables:

# Check if .env exists
ls -la .env

# Verify contents (be careful not to expose tokens!)
cat .env | grep -v TOKEN | grep -v KEY

Invalid Discord token

Symptoms:

Bot fails to connect
“Unauthorized” errors in logs

Solutions:

Verify the token is correct (no extra spaces)
Regenerate the token in Discord Developer Portal
Ensure the bot user is created in your application

ImgBB upload failures

Symptoms:

Images not saving
HTTP 401 errors

Solutions:

Verify your ImgBB API key is valid
Check ImgBB rate limits
Ensure your account is active

Database connection errors

Symptoms:

“unable to open database file”
Permission denied errors

Solutions:

Ensure the database directory exists
Check file permissions: chmod 755 <directory>
Verify the path in DATABASE_URL is correct
For Docker, ensure volume mounts are configured

Environment variables not loading in Docker

Ensure your docker-compose.yml includes the env_file directive:

services:
  discord-bot:
    env_file:
      - .env

Or pass variables explicitly:

services:
  discord-bot:
    environment:
      - DISCORD_TOKEN=${DISCORD_TOKEN}
      - IMGBB_KEY=${IMGBB_KEY}
      - DATABASE_URL=${DATABASE_URL}

Getting Started

Deployment

User Guide

Commands

Configuration File

Environment Variables

Example Configuration

Configuration Loading

Discord Bot Setup

ImgBB API Setup

Database Configuration

Local Development

Docker Deployment

Production Deployment

Database Connection Pool

Connection Pool

Auto-creation

Auto-migrations

Thread-safe

Security Best Practices

Protecting Your Credentials

Environment-Specific Configuration

Validation and Error Handling

Troubleshooting

Next Steps

Docker Deployment

Manual Installation

Build docs developers (and LLMs) love

Getting Started

Deployment

User Guide

Commands

​Configuration File

​Environment Variables

​Example Configuration

​Configuration Loading

​Discord Bot Setup

​ImgBB API Setup

​Database Configuration

​Local Development

​Docker Deployment

​Production Deployment

​Database Connection Pool

Connection Pool

Auto-creation

Auto-migrations

Thread-safe

​Security Best Practices

​Protecting Your Credentials

​Environment-Specific Configuration

​Validation and Error Handling

​Troubleshooting

​Next Steps

Docker Deployment

Manual Installation

Build docs developers (and LLMs) love

Configuration File

Environment Variables

Example Configuration

Configuration Loading

Discord Bot Setup

ImgBB API Setup

Database Configuration

Local Development

Docker Deployment

Production Deployment

Database Connection Pool

Security Best Practices

Protecting Your Credentials

Environment-Specific Configuration

Validation and Error Handling

Troubleshooting

Next Steps