Environments

Azu supports three environments with different default behaviors.

Environment Enum

enum Azu::Environment
  Development
  Test
  Production
end

Setting Environment

Via Configuration

Azu.configure do |config|
  config.env = Azu::Environment::Production
end

Via Environment Variable

export AZU_ENV=production

Checking Environment

if Azu.env.production?
  # Production-only code
end

Azu.env.development?  # => Bool
Azu.env.test?         # => Bool
Azu.env.production?   # => Bool

Development Environment

Default settings for development:

Setting	Value	Purpose
Log level	Debug	Detailed logging
Template hot reload	true	Immediate changes
Error pages	Detailed	Full stack traces
Cache	Memory	Simple, local

Behavior

• Detailed error pages with stack traces

• Templates reloaded on each request

• Verbose logging of all requests

• Development-friendly error messages

Configuration

config.env = Azu::Environment::Development
config.log.level = Log::Severity::Debug
config.template_hot_reload = true

Test Environment

Default settings for testing:

Setting	Value	Purpose
Log level	Warn	Less noise
Template hot reload	false	Faster tests
Error pages	Simple	JSON errors
Cache	Memory	Isolated

Behavior

• Minimal logging to reduce noise

• Cached templates for speed

• JSON error responses

• Isolated test database

Configuration

config.env = Azu::Environment::Test
config.log.level = Log::Severity::Warn
config.template_hot_reload = false

Test Setup

# spec/spec_helper.cr
ENV["AZU_ENV"] = "test"
ENV["DATABASE_URL"] = "sqlite3://./test.db"

Spec.before_each do
  # Reset database
  TestDatabase.truncate_all
end

Production Environment

Default settings for production:

Setting	Value	Purpose
Log level	Info	Important events
Template hot reload	false	Performance
Error pages	Simple	Security
Cache	Redis	Distributed

Behavior

• Minimal, structured logging

• Compiled and cached templates

• Generic error messages (no stack traces)

• External cache (Redis)

• SSL recommended

Configuration

config.env = Azu::Environment::Production
config.log.level = Log::Severity::Info
config.template_hot_reload = false
config.cache = Azu::Cache::RedisStore.new(url: ENV["REDIS_URL"])

Security Considerations

• Stack traces hidden from users

• Sensitive data not logged

• HTTPS enforced

• Security headers enabled

Environment Files

.env Files

# .env.development
AZU_ENV=development
PORT=4000
DATABASE_URL=sqlite3://./dev.db

# .env.test
AZU_ENV=test
PORT=4001
DATABASE_URL=sqlite3://./test.db

# .env.production (never commit!)
AZU_ENV=production
PORT=8080
DATABASE_URL=postgres://user:pass@host/db
REDIS_URL=redis://redis:6379/0
SECRET_KEY=actual-secret

Loading Environment

# Load environment file based on AZU_ENV
env_file = ".env.#{ENV.fetch("AZU_ENV", "development")}"
if File.exists?(env_file)
  File.each_line(env_file) do |line|
    next if line.starts_with?("#") || line.blank?
    key, value = line.split("=", 2)
    ENV[key.strip] = value.strip
  end
end

Complete Example

module MyApp
  include Azu

  configure do
    env_name = ENV.fetch("AZU_ENV", "development")

    case env_name
    when "production"
      config.env = Environment::Production
      config.port = ENV.fetch("PORT", "8080").to_i
      config.host = "0.0.0.0"

      # Logging
      config.log.level = Log::Severity::Info
      config.log.backend = JsonLogBackend.new(STDOUT)

      # Templates
      config.template_hot_reload = false

      # Cache
      config.cache = Cache::RedisStore.new(
        url: ENV["REDIS_URL"],
        namespace: "myapp:prod"
      )

      # SSL
      if ssl_cert = ENV["SSL_CERT"]?
        config.ssl = {cert: ssl_cert, key: ENV["SSL_KEY"]}
      end

    when "test"
      config.env = Environment::Test
      config.port = 4001
      config.log.level = Log::Severity::Warn
      config.template_hot_reload = false
      config.cache = Cache::MemoryStore.new

    else # development
      config.env = Environment::Development
      config.port = 4000
      config.log.level = Log::Severity::Debug
      config.template_hot_reload = true
      config.cache = Cache::MemoryStore.new
    end
  end
end

See Also

• Configuration Options

• How to Configure Production