goca middleware

Generate a dedicated middleware package for HTTP handlers.

Syntax

goca middleware <name> [flags]

Description

The goca middleware command generates an internal/middleware/ package containing composable HTTP middleware functions. Each middleware follows the standard func(http.Handler) http.Handler signature and can be chained together using the generated Chain() helper.

Composable Design

Generated middleware is designed to work with any net/http compatible router (gorilla/mux, chi, standard library). Use middleware.Chain() to compose multiple middleware in a single call.

Supported Middleware Types

Type	Function	Description
cors	CORS(cfg CORSConfig)	Configurable CORS headers (origins, methods, headers)
logging	Logging()	Structured request logging with method, path, status, duration
auth	Auth()	JWT Bearer token validation with claims extraction into context
rate-limit	RateLimit(cfg RateLimitConfig)	Per-IP token bucket rate limiting
recovery	Recovery(debugMode bool)	Panic recovery returning JSON 500 with optional stack trace
request-id	RequestID()	Inject X-Request-ID into context and response headers
timeout	Timeout(d time.Duration)	Per-request context deadline

Generated Files

internal/middleware/
├── middleware.go      # Middleware type + Chain() helper (always)
├── cors.go            # CORS middleware
├── logging.go         # Request logging middleware
├── auth.go            # JWT authentication middleware
├── rate_limit.go      # Rate limiting middleware
├── recovery.go        # Panic recovery middleware
├── request_id.go      # Request ID middleware
└── timeout.go         # Request timeout middleware

Only the types specified by --types are generated. The middleware.go chain helper is always included.

Flags

--types

Comma-separated list of middleware types to generate.

goca middleware MyApp --types cors,logging,auth,recovery

Default: cors,logging,recoverySupported values: cors, logging, auth, rate-limit, recovery, request-id, timeout

--dry-run

Preview what files would be generated without writing anything to disk.

goca middleware MyApp --dry-run

--force

Overwrite existing middleware files without prompting.

goca middleware MyApp --force

--backup

Create backups of existing files before overwriting.

goca middleware MyApp --backup

Usage Examples

Default middleware (CORS + Logging + Recovery)

goca middleware MyApp

Generates middleware.go, cors.go, logging.go, and recovery.go.

All middleware types

goca middleware MyApp --types cors,logging,auth,rate-limit,recovery,request-id,timeout

Auth-focused setup

goca middleware MyApp --types auth,rate-limit,cors,logging

Preview before generating

goca middleware MyApp --types cors,logging,auth --dry-run

Using Generated Middleware

Chaining middleware with a router

package main

import (
    "net/http"
    "time"

    "github.com/gorilla/mux"
    "myproject/internal/middleware"
)

func main() {
    r := mux.NewRouter()

    // Compose middleware
    stack := middleware.Chain(
        middleware.Recovery(true),
        middleware.Logging(),
        middleware.CORS(middleware.DefaultCORSConfig()),
        middleware.Timeout(30 * time.Second),
    )

    // Apply to router
    http.ListenAndServe(":8080", stack(r))
}

Accessing JWT claims in a handler

func (h *UserHandler) GetProfile(w http.ResponseWriter, r *http.Request) {
    claims, ok := middleware.ClaimsFromContext(r.Context())
    if !ok {
        http.Error(w, "unauthorized", http.StatusUnauthorized)
        return
    }
    userID := claims["sub"].(string)
    // ...
}

Accessing the request ID

func (h *Handler) Create(w http.ResponseWriter, r *http.Request) {
    reqID := middleware.RequestIDFromContext(r.Context())
    log.Printf("[%s] creating resource", reqID)
    // ...
}

Custom CORS configuration

corsConfig := middleware.CORSConfig{
    AllowedOrigins: []string{"https://myapp.com", "https://admin.myapp.com"},
    AllowedMethods: []string{"GET", "POST", "PUT", "DELETE"},
    AllowedHeaders: []string{"Content-Type", "Authorization"},
}
middleware.CORS(corsConfig)

External Dependencies

Some middleware types require external packages. Goca does not automatically run go get for these — add them to your project as needed:

Type	Dependency
auth	github.com/golang-jwt/jwt/v5
rate-limit	golang.org/x/time
request-id	github.com/google/uuid

Integration with Other Commands

Scenario	Related Command
Generate handlers that use middleware	goca handler <entity> --middleware
Generate a full feature with handlers	goca feature <entity> --fields "..."
Wire middleware into DI container	goca di

See Also

• Commands Overview
• goca handler
• goca feature