🔑 Where to Configure Ports in .NET Core

 There are 3 main ways:

---

1️⃣ launchSettings.json (Local Development Only)

• Located in:
  Properties/launchSettings.json

Example:

{
  "profiles": {
    "ProductService": {
      "commandName": "Project",
      "dotnetRunMessages": true,
      "applicationUrl": "http://localhost:5002;https://localhost:7002",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

👉 This means:

• ProductService will listen on http://localhost:5002 and https://localhost:7002.

• Useful for local debugging.

---

2️⃣ appsettings.json or appsettings.{Environment}.json

• You can configure Kestrel endpoints directly.

Example:

{
  "Kestrel": {
    "Endpoints": {
      "Http": {
        "Url": "http://localhost:5002"
      },
      "Https": {
        "Url": "https://localhost:7002"
      }
    }
  }
}

👉 This works in development, staging, and production.
👉 More flexible, especially when deploying in Docker/Kubernetes.

---

3️⃣ Hardcode in Program.cs (Not Recommended for Production)

var builder = WebApplication.CreateBuilder(args);

builder.WebHost.UseUrls("http://localhost:5002", "https://localhost:7002");

var app = builder.Build();
app.MapControllers();
app.Run();

👉 Quick way to bind to specific ports, but harder to manage in large deployments.

---

⚙️ Best Practices

1. Local Development → use launchSettings.json.

2. Production (IIS, Azure, Docker, Kubernetes) →

   • Use appsettings.json (Kestrel:Endpoints).

   • Or environment variables → DOTNET_URLS=http://+:5002.

3. Dockerized Microservices → expose ports in Dockerfile / docker-compose.yml. Example:

   EXPOSE 5002
   

   ports:
     - "5002:5002"
   

---

✅ Summary

• launchSettings.json → local dev only.

• appsettings.json (Kestrel) → preferred for production.

• Program.cs → UseUrls() → quick overrides.

• Environment Variables / Docker → best in containerized/cloud setups.