Ginミドルウェア：認証とロギング

func MyMiddleware() gin.HandlerFunc {
    return func(c *gin.Context) {
        // before handler
        c.Next()
        // after handler
    }
}

r := gin.New()
r.Use(gin.Logger())
r.Use(gin.Recovery())

func ZapLogger(logger *zap.Logger) gin.HandlerFunc {
    return func(c *gin.Context) {
        start := time.Now()
        c.Next()
        logger.Info("request",
            zap.String("method", c.Request.Method),
            zap.String("path", c.FullPath()),
            zap.Int("status", c.Writer.Status()),
            zap.Duration("latency", time.Since(start)),
        )
    }
}

func AuthRequired() gin.HandlerFunc {
    return func(c *gin.Context) {
        token := c.GetHeader("Authorization")
        claims, err := validateJWT(token)
        if err != nil {
            c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid token"})
            return
        }
        c.Set("user", claims)
        c.Next()
    }
}

user, _ := c.Get("user")
claims := user.(*Claims)

r.Use(gin.CustomRecovery(func(c *gin.Context, recovered any) {
    log.Printf("panic: %v", recovered)
    c.AbortWithStatusJSON(500, gin.H{"error": "internal server error"})
}))

r.Use(cors.New(cors.Config{
    AllowOrigins:     []string{"https://example.com"},
    AllowMethods:     []string{"GET", "POST", "PUT"},
    AllowHeaders:     []string{"Authorization", "Content-Type"},
    AllowCredentials: true,
}))

func RequestID() gin.HandlerFunc {
    return func(c *gin.Context) {
        id := uuid.New().String()
        c.Set("requestID", id)
        c.Header("X-Request-ID", id)
        c.Next()
    }
}

admin := r.Group("/admin")
admin.Use(AuthRequired(), AdminOnly())
admin.GET("/users", listUsers)