HTTP Routing

Platforma’s HTTP routing is built on Go’s http.ServeMux with enhanced support for middleware, route grouping, and domain organization.

HTTPServer

The HTTPServer type from httpserver/httpserver.go:18 is a service that runs an HTTP server with graceful shutdown:

type HTTPServer struct {
    *HandlerGroup
    port            string
    shutdownTimeout time.Duration
}

Creating an HTTP Server

From httpserver/httpserver.go:25:

import (
    "time"
    "github.com/platforma-dev/platforma/httpserver"
)

// Create server on port 8080 with 5 second shutdown timeout
api := httpserver.New("8080", 5*time.Second)

The shutdown timeout controls how long the server waits for in-flight requests to complete during graceful shutdown.

Registering with Application

HTTP servers implement the Runner interface and can be registered as services:

app := application.New()
app.RegisterService("api", api)

The server starts when you run ./myapp run and shuts down gracefully on interrupt signals.

Route Registration

Handle() - Register Handlers

Use the Handle() method from httpserver/handlergroup.go:31 with Go 1.22+ routing syntax:

api.Handle("GET /users", getUsersHandler)
api.Handle("POST /users", createUserHandler)
api.Handle("GET /users/{id}", getUserHandler)
api.Handle("PUT /users/{id}", updateUserHandler)
api.Handle("DELETE /users/{id}", deleteUserHandler)

The pattern "METHOD /path" syntax requires Go 1.22 or later. This gives you method-specific routing without external libraries.

HandleFunc() - Register Functions

From httpserver/handlergroup.go:36, for simple function handlers:

api.HandleFunc("/ping", func(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("pong"))
})

Path Parameters

Extract path parameters using Go’s standard library:

api.HandleFunc("GET /users/{id}", func(w http.ResponseWriter, r *http.Request) {
    userID := r.PathValue("id")
    
    // Use userID...
    w.Write([]byte("User ID: " + userID))
})

HandlerGroup

The HandlerGroup type from httpserver/handlergroup.go:8 organizes routes that share common middleware:

type HandlerGroup struct {
    mux         *http.ServeMux
    middlewares []Middleware
}

Creating Handler Groups

From httpserver/handlergroup.go:14:

// Create a new handler group
adminAPI := httpserver.NewHandlerGroup()

// Add routes
adminAPI.Handle("GET /stats", getStatsHandler)
adminAPI.Handle("POST /config", updateConfigHandler)

// Apply middleware to all routes in this group
adminAPI.Use(adminAuthMiddleware)
adminAPI.Use(auditLogMiddleware)

Mounting Handler Groups

Use HandleGroup() from httpserver/handlergroup.go:41 to mount groups at a path prefix:

// Mount admin API under /admin
api.HandleGroup("/admin", adminAPI)

// Now accessible as:
// GET  /admin/stats
// POST /admin/config

HandleGroup() automatically strips the prefix before routing. Routes in the group should be defined without the mount prefix.

Complete Example

From demo-app/cmd/api/main.go:13, showing server setup with groups:

package main

import (
    "context"
    "net/http"
    "time"

    "github.com/platforma-dev/platforma/application"
    "github.com/platforma-dev/platforma/httpserver"
    "github.com/platforma-dev/platforma/log"
)

func main() {
    ctx := context.Background()
    app := application.New()

    // Create HTTP server
    api := httpserver.New("8080", 3*time.Second)

    // Add top-level endpoints
    api.HandleFunc("/ping", func(w http.ResponseWriter, r *http.Request) {
        w.Write([]byte("pong"))
    })

    api.HandleFunc("/long", func(w http.ResponseWriter, r *http.Request) {
        time.Sleep(10 * time.Second)
        w.Write([]byte("pong"))
    })

    // Add middleware to entire server
    api.Use(log.NewTraceIDMiddleware(nil, ""))

    // Create handler group
    subApiGroup := httpserver.NewHandlerGroup()

    // Add endpoint to group
    subApiGroup.HandleFunc("/clock", func(w http.ResponseWriter, r *http.Request) {
        w.Write([]byte(time.Now().String()))
    })

    // Add middleware to group only
    subApiGroup.UseFunc(func(h http.Handler) http.Handler {
        return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            log.InfoContext(r.Context(), "incoming request", "addr", r.RemoteAddr)
            h.ServeHTTP(w, r)
        })
    })

    // Mount group at /subApi
    api.HandleGroup("/subApi", subApiGroup)

    // Register server
    app.RegisterService("api", api)

    // Run application
    if err := app.Run(ctx); err != nil {
        log.ErrorContext(ctx, "app finished with error", "error", err)
    }
}

This creates:

GET /ping - Top-level endpoint with trace ID middleware
GET /long - Top-level endpoint (tests graceful shutdown)
GET /subApi/clock - Group endpoint with both trace ID and logging middleware

Mounting Domain APIs

Domains expose their HTTP API via a HandlerGroup:

// From auth/domain.go:30
authAPI := httpserver.NewHandlerGroup()
authAPI.Handle("POST /register", registerHandler)
authAPI.Handle("POST /login", loginHandler)
authAPI.Handle("POST /logout", logoutHandler)
authAPI.Handle("GET /me", getUserHandler)
authAPI.Handle("POST /change-password", changePasswordHandler)
authAPI.Handle("DELETE /me", deleteHandler)

Mount it in your main application:

api := httpserver.New("8080", 5*time.Second)
api.HandleGroup("/auth", authDomain.HandleGroup)
app.RegisterService("api", api)

This pattern keeps domain routing logic inside the domain while giving you flexibility in how you expose it.

Middleware Application

Server-Level Middleware

Applies to all routes on the server:

api := httpserver.New("8080", 5*time.Second)
api.Use(log.NewTraceIDMiddleware(nil, ""))
api.Use(corsMiddleware)

Group-Level Middleware

Applies only to routes in the group from httpserver/handlergroup.go:19:

protectedAPI := httpserver.NewHandlerGroup()
protectedAPI.Use(authMiddleware)  // Only affects this group
protectedAPI.Handle("GET /profile", getProfileHandler)

api.HandleGroup("/user", protectedAPI)

UseFunc() - Inline Middleware

From httpserver/handlergroup.go:24, add middleware as a function:

group.UseFunc(func(h http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        // Before request
        log.InfoContext(r.Context(), "request started")
        
        h.ServeHTTP(w, r)
        
        // After request
        log.InfoContext(r.Context(), "request completed")
    })
})

Middleware Ordering

Middleware is applied in reverse order from httpserver/middleware.go:26:

// Applied as: traceID -> logging -> auth -> handler
api.Use(traceIDMiddleware)   // Outermost
api.Use(loggingMiddleware)
api.Use(authMiddleware)      // Innermost

The first registered middleware is the outermost wrapper. Request flow: trace ID → logging → auth → handler. Response flow is reversed.

Route Organization Patterns

Pattern 1: Versioned APIs

v1 := httpserver.NewHandlerGroup()
v1.Handle("GET /users", v1GetUsersHandler)
v1.Handle("POST /users", v1CreateUserHandler)

v2 := httpserver.NewHandlerGroup()
v2.Handle("GET /users", v2GetUsersHandler)
v2.Handle("POST /users", v2CreateUserHandler)

api.HandleGroup("/v1", v1)
api.HandleGroup("/v2", v2)

Pattern 2: Public vs Protected

publicAPI := httpserver.NewHandlerGroup()
publicAPI.Handle("GET /health", healthHandler)
publicAPI.Handle("POST /webhooks/stripe", stripeWebhookHandler)

protectedAPI := httpserver.NewHandlerGroup()
protectedAPI.Use(authMiddleware)
protectedAPI.Handle("GET /profile", profileHandler)
protectedAPI.Handle("POST /upload", uploadHandler)

api.HandleGroup("/public", publicAPI)
api.HandleGroup("/api", protectedAPI)

Pattern 3: Domain-Based

userDomain := user.New(db)
orderDomain := order.New(db)
productDomain := product.New(db)

api := httpserver.New("8080", 5*time.Second)
api.HandleGroup("/users", userDomain.HandleGroup)
api.HandleGroup("/orders", orderDomain.HandleGroup)
api.HandleGroup("/products", productDomain.HandleGroup)

Graceful Shutdown

From httpserver/httpserver.go:30, the server handles shutdown automatically:

func (s *HTTPServer) Run(ctx context.Context) error {
    server := &http.Server{
        Addr:              ":" + s.port,
        Handler:           wrapHandlerInMiddleware(s.mux, s.middlewares),
        ReadHeaderTimeout: 1 * time.Second,
    }

    go func() {
        log.InfoContext(ctx, "starting http server", "address", server.Addr)
        if err := server.ListenAndServe(); !errors.Is(err, http.ErrServerClosed) {
            log.ErrorContext(ctx, "HTTP server error", "error", err)
        }
    }()

    <-ctx.Done()  // Wait for shutdown signal

    shutdownCtx, cancel := context.WithTimeout(
        context.Background(), 
        s.shutdownTimeout,
    )
    defer cancel()

    if err := server.Shutdown(shutdownCtx); err != nil {
        return fmt.Errorf("failed to gracefully shutdown: %w", err)
    }
    
    log.InfoContext(ctx, "graceful shutdown completed")
    return nil
}

In-flight requests have shutdownTimeout duration to complete before the server force-closes connections.

Health Checks

The HTTPServer implements Healthchecker from httpserver/httpserver.go:62:

func (s *HTTPServer) Healthcheck(_ context.Context) any {
    return map[string]any{
        "port": s.port,
    }
}

This is automatically included when you register the server:

app.RegisterService("api", api)
health := app.Health(ctx)
// health.Services["api"] contains port information

Advanced Routing

Wildcard Paths

// Match anything under /static/
api.Handle("/static/", http.StripPrefix("/static/", 
    http.FileServer(http.Dir("./static"))))

Method-Specific Routing

// Same path, different methods
api.Handle("GET /items/{id}", getItemHandler)
api.Handle("PUT /items/{id}", updateItemHandler)
api.Handle("DELETE /items/{id}", deleteItemHandler)

Multiple Path Params

api.HandleFunc("GET /users/{userID}/posts/{postID}", 
    func(w http.ResponseWriter, r *http.Request) {
        userID := r.PathValue("userID")
        postID := r.PathValue("postID")
        
        // Handle request...
    },
)

Get Started

Core Concepts

Guides

HTTPServer

Creating an HTTP Server

Registering with Application

Route Registration

Handle() - Register Handlers

HandleFunc() - Register Functions

Path Parameters

HandlerGroup

Creating Handler Groups

Mounting Handler Groups

Complete Example

Mounting Domain APIs

Middleware Application

Server-Level Middleware

Group-Level Middleware

UseFunc() - Inline Middleware

Middleware Ordering

Route Organization Patterns

Pattern 1: Versioned APIs

Pattern 2: Public vs Protected

Pattern 3: Domain-Based

Graceful Shutdown

Health Checks

Advanced Routing

Wildcard Paths

Method-Specific Routing

Multiple Path Params

Next Steps

Middleware

Domains

Application Lifecycle

​HTTPServer

​Creating an HTTP Server

​Registering with Application

​Route Registration

​Handle() - Register Handlers

​HandleFunc() - Register Functions

​Path Parameters

​HandlerGroup

​Creating Handler Groups

​Mounting Handler Groups

​Complete Example

​Mounting Domain APIs

​Middleware Application

​Server-Level Middleware

​Group-Level Middleware

​UseFunc() - Inline Middleware

​Middleware Ordering

​Route Organization Patterns

​Pattern 1: Versioned APIs

​Pattern 2: Public vs Protected

​Pattern 3: Domain-Based

​Graceful Shutdown

​Health Checks

​Advanced Routing

​Wildcard Paths

​Method-Specific Routing

​Multiple Path Params

​Next Steps

Middleware

Domains

Application Lifecycle

HTTPServer

Creating an HTTP Server

Registering with Application

Route Registration

Handle() - Register Handlers

HandleFunc() - Register Functions

Path Parameters

HandlerGroup

Creating Handler Groups

Mounting Handler Groups

Complete Example

Mounting Domain APIs

Middleware Application

Server-Level Middleware

Group-Level Middleware

UseFunc() - Inline Middleware

Middleware Ordering

Route Organization Patterns

Pattern 1: Versioned APIs

Pattern 2: Public vs Protected

Pattern 3: Domain-Based

Graceful Shutdown

Health Checks

Advanced Routing

Wildcard Paths

Method-Specific Routing

Multiple Path Params

Next Steps