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Samuel Arogbonlo
Samuel Arogbonlo

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Dynamic HTTP Server Configuration in Go with gorealconf

Managing configuration changes safely and efficiently is a critical challenge in today's cloud-native world. When building distributed systems, we often need to update configurations without downtime, ensure type safety, and roll out changes gradually. These requirements led me to create gorealconf, a library that brings robust, type-safe configuration management to Go applications.

Key Challenges

Before diving into gorealconf's features, let's understand the core challenges in modern configuration management:

  1. Applications often require restarts to apply configuration changes
  2. Type safety is frequently sacrificed for flexibility
  3. Rolling out changes safely across distributed systems is complex
  4. Validating configuration changes and handling failures gracefully is difficult
  5. Monitoring and tracking configuration changes becomes unwieldy at scale

gorealconf addresses these challenges through thoughtful design and powerful features that make configuration management safer and more efficient.

Core Features and Implementation

Type Safety Through Go Generics

One of gorealconf's fundamental strengths is its use of Go generics to ensure type safety at compile time:

type DatabaseConfig struct {
    MaxConnections int           `json:"max_connections"`
    ReadTimeout    time.Duration `json:"read_timeout"`
    WriteTimeout   time.Duration `json:"write_timeout"`
}

// Create a type-safe configuration instance
cfg := gorealconf.New[DatabaseConfig](
    gorealconf.WithValidation[DatabaseConfig](validateConfig),
    gorealconf.WithRollback[DatabaseConfig](true),
)
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This approach eliminates runtime type errors while maintaining a clean, intuitive API.

Real-Time Configuration Updates

gorealconf enables zero-downtime configuration changes through its watch mechanism:

changes, _ := cfg.Watch(context.Background())
go func() {
    for newCfg := range changes {
        updateDatabaseConnections(newCfg)
    }
}()
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Changes propagate automatically to all components, ensuring consistency across your application.

Gradual Rollouts with Safety Controls

One of gorealconf's most powerful features is its support for gradual rollouts:

rollout := gorealconf.NewRollout[FeatureConfig](cfg).
    WithStrategy(gorealconf.NewPercentageStrategy(10)).
    WithValidation(validateFeature).
    WithRollbackThreshold(0.01) // Rollback if error rate exceeds 1%
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This allows you to safely test configuration changes with a subset of your instances before full deployment.

Real-World Applications

Dynamic HTTP Server Configuration

Here's how gorealconf can manage a production HTTP server:

type ServerConfig struct {
    Port         int           `json:"port"`
    ReadTimeout  time.Duration `json:"read_timeout"`
    WriteTimeout time.Duration `json:"write_timeout"`
}

func main() {
    cfg := gorealconf.New[ServerConfig]()

    // Initialize server with configuration
    server := createServer(cfg.Get(ctx))

    // Watch for configuration updates
    changes, _ := cfg.Watch(context.Background())
    go handleConfigChanges(changes, server)

    // Start server
    server.ListenAndServe()
}
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Feature Flag Management

gorealconf excels at managing feature flags and A/B testing:

type FeatureFlags struct {
    NewUI          bool    `json:"new_ui"`
    BetaFeatures   bool    `json:"beta_features"`
    RolloutPercent float64 `json:"rollout_percent"`
}

rollout := gorealconf.NewRollout[FeatureFlags](cfg).
    WithStrategy(gorealconf.NewCompositeStrategy().
        Add(gorealconf.NewRegionBasedStrategy(regions)).
        Add(gorealconf.NewPercentageStrategy(20)),
    )
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Getting Started

Install gorealconf using:

go get github.com/samuelarogbonlo/gorealconf
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The library includes comprehensive examples in the examples/ directory, covering:

  • Basic usage
  • Multi-source configuration
  • Gradual rollouts
  • Complete application setups

What's Next?

The future roadmap for gorealconf includes:

  • Enhanced encryption support
  • Additional configuration sources
  • Advanced rollout strategies
  • Improved observability features
  • Others etc.

Join the Community

gorealconf is open source and welcomes contributions. Whether you fix bugs, add features, or improve documentation, your help makes the library better for everyone.

Check out the GitHub repository to get started, and join our community discussions to share your ideas and experiences. Also the package details here

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