Propel.FeatureFlags.PostgreSql 2.2.1

Propel.FeatureFlags.PostgreSql

PostgreSQL repository implementation for Propel.FeatureFlags, providing persistent storage for feature flag configurations and evaluations.

Features

• PostgreSQL Storage - Feature flag storage using PostgreSQL
• Connection Pooling - Connection management with configurable pool settings
• Auto-Initialization - Automatic database and table creation on startup
• Resilience Configuration - Built-in timeout and retry settings for production workloads
• Schema Management - Handles database schema creation and migrations automatically

Installation

dotnet add package Propel.FeatureFlags.PostgreSql

Quick Start

Basic Configuration

using Propel.FeatureFlags.PostgreSql.Extensions;

var builder = WebApplication.CreateBuilder(args);

// Add PostgreSQL feature flag repository
builder.Services
    .ConfigureFeatureFlags(config =>
    {
        config.RegisterFlagsWithContainer = true;
        config.EnableFlagFactory = true;
    })
    .AddPostgreSqlFeatureFlags(builder.Configuration.GetConnectionString("DefaultConnection")!);

var app = builder.Build();

// Initialize database (development only)
if (app.Environment.IsDevelopment())
{
    await app.InitializeFeatureFlagsDatabase();
}

// Auto-deploy flags to database
await app.AutoDeployFlags();

app.Run();

Console Application

using Propel.FeatureFlags.PostgreSql.Extensions;

var builder = Host.CreateApplicationBuilder(args);

builder.Services
    .ConfigureFeatureFlags(config =>
    {
        config.RegisterFlagsWithContainer = true;
        config.EnableFlagFactory = true;
    })
    .AddPostgreSqlFeatureFlags(builder.Configuration.GetConnectionString("DefaultConnection")!);

var app = builder.Build();

// Initialize database in development
if (app.Services.GetRequiredService<IHostEnvironment>().IsDevelopment())
{
    await app.InitializeFeatureFlagsDatabase();
}

await app.AutoDeployFlags();

await app.RunAsync();

Configuration

Connection String The extension automatically configures the PostgreSQL connection with optimized settings:

{
  "ConnectionStrings": {
    "DefaultConnection": "Host=localhost,5432;Database=feature_flags;Search Path=example;Username=postgres-user;Password=postgres-password"
  }
}

Automatic Connection Optimization

The AddPostgreSqlFeatureFlags() method automatically applies the following settings:

Extension Methods

AddPostgreSqlFeatureFlags(string connectionString) registers PostgreSQL as the feature flag repository with optimized connection settings.

builder.Services
    .ConfigureFeatureFlags(config => { ... })
    .AddPostgreSqlFeatureFlags(connectionString);

InitializeFeatureFlagsDatabase() creates the database schema if it doesn't exist. Recommended for development environments only.

if (app.Environment.IsDevelopment())
{
    await app.InitializeFeatureFlagsDatabase();
}

Important Notes:

• In production, this method will throw an exception and stop the application if initialization fails
• In development/staging, the application continues running to allow troubleshooting
• Only call this method during application startup, not on every request

Database Schema

The extension automatically creates the following database objects:

• Tables - Feature flags, variations, targeting rules, rollout configurations
• Indexes - Optimized for common query patterns
• Constraints - Ensures data integrity

Schema creation happens automatically when calling InitializeFeatureFlagsDatabase().

Production Deployment

For production environments, it's recommended to deploy the database schema from CI/CD pipelines instead of using InitializeFeatureFlagsDatabase(). You can use the Propel CLI utility to automate schema deployment as part of your deployment pipeline. This approach provides better control over database changes, enables schema versioning, and follows infrastructure-as-code best practices.

Example CI/CD pipeline command propel-cli migrate --connection-string "Host=prod_server;Database=feature_flags;..."

Usage Example

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services
            .ConfigureFeatureFlags(config =>
            {
                config.RegisterFlagsWithContainer = true;
                config.EnableFlagFactory = true;
            })
            .AddPostgreSqlFeatureFlags(Configuration.GetConnectionString("DefaultConnection")!);
    }

    public async Task Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            // Create database schema
            await app.ApplicationServices
                .GetRequiredService<IHost>()
                .InitializeFeatureFlagsDatabase();
        }

        // Deploy flags to database
        await app.ApplicationServices
            .GetRequiredService<IHost>()
            .AutoDeployFlags();
    }
}

Related Packages

• Propel.FeatureFlags - Core feature flag library
• Propel.FeatureFlags.DependencyInjection.Extensions - Container extensions
• Propel.FeatureFlags.Redis - Redis caching provider
• Propel.FeatureFlags.AspNetCore - ASP.NET Core middleware
• Propel.FeatureFlags.Attributes - Attribute-based feature flagging