Timo Riegebauer
ae5d1f610a
- Run global middleware for all requests, including OPTIONS preflights, NotFound, and MethodNotAllowed — previously bypassed by httprouter's internal handling - Implement Hijacker, Flusher, and Pusher on the response writer for WebSocket, SSE, and HTTP/2 push support - Fix CORS: echo a single matching origin, handle AllowCredentials with wildcard, append Vary: Origin - Logger logs from a defer to capture correct status on panicked requests - Static and StaticFS accept route middleware; add Context.AddHeader; warn on NotFound handler override
525 lines
18 KiB
Markdown
525 lines
18 KiB
Markdown
# go-kite
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A fast, lightweight, and expressive HTTP framework for Go, built on top of [httprouter](https://github.com/julienschmidt/httprouter).
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> **~132,000 req/sec** · **sub-4ms latency** · **~58MB RAM at peak load**
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## Features
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- **Fast** — ~132k RPS, sitting just below raw `net/http` and above Gin, Echo, and Chi
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- **Middleware** — global, group, and route-level middleware with correct onion ordering
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- **Groups** — nestable route groups with prefix and middleware inheritance
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- **Static files & SPA** — serve assets and single-page apps with optional middleware
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- **Graceful shutdown** — in-flight requests finish cleanly on `SIGTERM` / `SIGINT`
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- **Configurable** — server timeouts, error/not-found/method-not-allowed handlers
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- **Rich context** — typed request/response helpers, value store, cookie and form support
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- **Built-in middleware** — logger, recovery, CORS, request ID, max body size
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- **WebSocket & SSE ready** — response writer implements `Hijacker`, `Flusher`, and `Pusher`
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## Installation
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```bash
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go get git.trcreatives.at/trcreatives/go-kite
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```
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## Quickstart
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```go
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package main
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import (
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"net/http"
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"log"
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"git.trcreatives.at/trcreatives/go-kite"
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"git.trcreatives.at/trcreatives/go-kite/middleware"
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)
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func main() {
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k := kite.New()
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k.Use(
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middleware.Logger(), // first, so it observes the final status after Recovery
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middleware.Recovery(),
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middleware.RequestID(),
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)
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k.GET("/", func(ctx *kite.Context) error {
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return ctx.WriteJSON(http.StatusOK, map[string]string{
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"message": "Hello, World!",
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})
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})
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if err := k.Start("localhost:8080"); err != nil {
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log.Fatal(err)
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}
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}
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```
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## Routing
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```go
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k := kite.New()
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k.GET("/users", listUsers)
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k.POST("/users", createUser)
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k.GET("/users/:id", getUser)
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k.PUT("/users/:id", updateUser)
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k.DELETE("/users/:id", deleteUser)
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```
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Supported HTTP methods: `GET`, `POST`, `PUT`, `DELETE`, `HEAD`, `OPTIONS`, `CONNECT`, `TRACE`.
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## Route Groups
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Groups allow you to share a common prefix and middleware across multiple routes.
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```go
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api := k.Group("/api")
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api.GET("/users", listUsers) // GET /api/users
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api.POST("/users", createUser) // POST /api/users
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```
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Groups can be nested:
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```go
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api := k.Group("/api")
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v1 := api.Group("/v1")
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v1.GET("/users", listUsers) // GET /api/v1/users
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```
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Middleware can be attached to groups:
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```go
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api := k.Group("/api", authMiddleware)
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admin := api.Group("/admin", adminOnlyMiddleware)
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admin.GET("/stats", getStats) // chain: global → auth → adminOnly → handler
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```
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## Static Files & Single-Page Apps
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### Static Assets
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`Static` serves files from a directory on disk under a URL prefix:
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```go
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k.Static("/assets", "./public")
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// GET /assets/css/main.css → ./public/css/main.css
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```
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Middleware can be applied per-prefix:
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```go
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k.Static("/admin/assets", "./admin-dist", authMiddleware)
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```
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`StaticFS` is the same but takes an `http.FileSystem`, useful for embedded assets via `embed`:
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```go
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//go:embed dist
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var distFS embed.FS
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k.StaticFS("/assets", http.FS(distFS))
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```
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Both are also available on `Group` for prefixed/scoped serving.
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### Single-Page Applications
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For Vue, React, Svelte, and similar frameworks, `SPA` serves the directory and falls back to `index.html` for unknown paths — letting client-side routing work correctly:
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```go
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k.SPA("./dist")
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```
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`SPAFS` takes an `http.FileSystem` for embedded builds.
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> **Note:** `SPA` and `SPAFS` register the file server as the NotFound handler. If you've already called `SetNotFoundHandler` (or call it afterward), a warning is logged about the override.
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## Middleware
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Middleware follows the standard onion model — each middleware wraps the next.
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```go
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type Middleware func(h Handler) Handler
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```
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### Global Middleware
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Applied to every request, including NotFound, MethodNotAllowed, and OPTIONS preflights:
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```go
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k.Use(middleware.Logger())
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k.Use(middleware.Recovery())
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```
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### Route Middleware
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Applied to a single route:
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```go
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k.GET("/admin", adminHandler, authMiddleware, rateLimitMiddleware)
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```
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### Execution Order
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```
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→ Global 1
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→ Global 2
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→ Group 1
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→ Route 1
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[Handler]
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← Route 1
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← Group 1
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← Global 2
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← Global 1
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```
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The first middleware registered is the outermost — it runs first on the way in, and last on the way out.
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### Recommended Order
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Register `Logger` **before** `Recovery`. The reverse order causes `Logger`'s deferred log line to read the status before `Recovery` writes the 500, which means panicked requests log as `200`.
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```go
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k.Use(
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middleware.Logger(), // outermost — sees the final status
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middleware.Recovery(), // catches panics from inner handlers
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middleware.RequestID(),
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)
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```
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### Writing Custom Middleware
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```go
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func MyMiddleware(h kite.Handler) kite.Handler {
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return func(ctx *kite.Context) error {
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// before handler
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err := h(ctx)
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// after handler
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return err
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}
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}
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```
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## Built-in Middleware
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All middleware lives in the `middleware` sub-package:
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```go
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import "git.trcreatives.at/trcreatives/go-kite/middleware"
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```
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### Logger
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Logs method, path, status code and latency for every request. Logs from a `defer`, so panicked and errored requests are captured too (provided Logger is registered before Recovery).
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```go
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// simple
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k.Use(middleware.Logger())
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// custom
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k.Use(middleware.LoggerWithConfig(middleware.LoggerConfig{
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Output: logFile,
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Format: func(method, path string, statusCode int, latency time.Duration) string {
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return fmt.Sprintf("%s %s %d %dms", method, path, statusCode, latency.Milliseconds())
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},
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Skip: func(ctx *kite.Context) bool {
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return ctx.GetPath() == "/health"
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},
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}))
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```
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### Recovery
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Catches panics and returns a `500` instead of crashing the server.
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```go
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// simple
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k.Use(middleware.Recovery())
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// custom — integrate with Sentry, Datadog, etc.
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k.Use(middleware.RecoveryWithConfig(middleware.RecoveryConfig{
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OnPanic: func(ctx *kite.Context, recovered any, stack []byte) error {
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sentry.CaptureException(fmt.Errorf("%v", recovered))
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return ctx.WriteJSON(http.StatusInternalServerError, map[string]string{
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"error": "internal server error",
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})
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},
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}))
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```
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### RequestID
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Attaches a unique ID to every request. Reuses an incoming `X-Request-ID` header if present, for distributed tracing.
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```go
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// simple
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k.Use(middleware.RequestID())
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// custom header
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k.Use(middleware.RequestIDWithConfig(middleware.RequestIDConfig{
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Header: "X-Trace-ID",
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}))
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// retrieve in handler
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id := ctx.GetValue("X-Request-ID").(string)
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```
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### CORS
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Sets Cross-Origin Resource Sharing headers and handles preflight requests.
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```go
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// allow all origins (no credentials)
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k.Use(middleware.CORS())
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// restrict to specific origins
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k.Use(middleware.CORS("https://myapp.com", "https://staging.myapp.com"))
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// full control
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k.Use(middleware.CORSWithConfig(middleware.CORSConfig{
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AllowedOrigins: []string{"https://myapp.com"},
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AllowedMethods: []string{"GET", "POST", "PUT", "DELETE"},
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AllowedHeaders: []string{"Content-Type", "Authorization"},
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ExposedHeaders: []string{"X-Request-ID"},
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AllowCredentials: true,
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MaxAge: 86400,
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}))
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```
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For multi-origin allowlists, the middleware checks the request's `Origin` against the list and echoes back only the matching one — `Access-Control-Allow-Origin` always contains a single origin, never a comma-separated list. A `Vary: Origin` header is added so caches behave correctly.
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> **Note:** When `AllowCredentials: true` is combined with `AllowedOrigins: ["*"]`, the middleware echoes the request's `Origin` instead of sending `*`, since browsers reject that combination.
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### MaxBodySize
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Protects against oversized request bodies. Returns `413` if the limit is exceeded.
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```go
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// global 4MB limit
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k.Use(middleware.MaxBodySize(4 << 20))
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// per-route override for file uploads
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k.POST("/upload", uploadHandler, middleware.MaxBodySize(100 << 20))
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```
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## Context
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Every handler receives a `*kite.Context` with the following methods:
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### Request
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| Method | Description |
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| ---------------------------------------------- | ------------------------------------- |
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| `GetRequest() *http.Request` | Underlying request |
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| `GetResponse() http.ResponseWriter` | Underlying response writer |
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| `GetContext() context.Context` | Underlying context |
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| `GetMethod() string` | HTTP method |
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| `GetPath() string` | Request path |
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| `IsMethod(method string) bool` | Check HTTP method |
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| `GetPathParam(key string) string` | Route parameter (e.g. `/users/:id`) |
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| `GetQueryParam(key string) string` | Query string parameter |
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| `GetHeader(key string) string` | Request header |
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| `GetIP() string` | Client IP, respects `X-Forwarded-For` |
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| `GetCookie(name string) (*http.Cookie, error)` | Request cookie |
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| `GetStatusCode() int` | Current response status code |
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### Values
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| Method | Description |
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| ----------------------------- | ---------------------------- |
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| `SetValue(key string, v any)` | Store a value in the context |
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| `GetValue(key string) any` | Retrieve a stored value |
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### Forms
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| Method | Description |
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| --------------------------------------------------------------------------------- | ----------------- |
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| `GetForm() (url.Values, error)` | All form values |
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| `GetFormValue(key string) string` | Single form value |
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| `GetMultipartForm(maxMemory int64) (*multipart.Form, error)` | Multipart form |
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| `GetMultipartFormFile(key string) (multipart.File, *multipart.FileHeader, error)` | Uploaded file |
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### Body Binding
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| Method | Description |
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| ----------------------- | ------------------------ |
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| `BindJSON(v any) error` | Decode JSON request body |
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| `BindXML(v any) error` | Decode XML request body |
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### Response
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| Method | Description |
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| ----------------------------------------- | ---------------------------------------- |
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| `WriteBytes(status int, v []byte) error` | Raw bytes response |
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| `WriteString(status int, v string) error` | Plain text response (UTF-8) |
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| `WriteJSON(status int, v any) error` | JSON response (UTF-8) |
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| `WriteXML(status int, v any) error` | XML response (UTF-8) |
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| `WriteNoContent() error` | 204 No Content |
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| `Redirect(status int, url string) error` | Redirect |
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| `SetHeader(key, value string)` | Set response header (replaces existing) |
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| `AddHeader(key, value string)` | Append response header (for multi-value) |
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| `SetCookie(cookie *http.Cookie)` | Set response cookie |
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## Error Handling
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Handlers return `error`. By default, errors are logged and a `500` is returned to the client.
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```go
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k.GET("/users/:id", func(ctx *kite.Context) error {
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user, err := db.GetUser(ctx.GetPathParam("id"))
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if err != nil {
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return err // caught by error handler
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}
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return ctx.WriteJSON(http.StatusOK, user)
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})
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```
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### Custom Error Handler
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```go
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k.SetErrorHandler(func(ctx *kite.Context, err error) error {
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return ctx.WriteJSON(http.StatusInternalServerError, map[string]string{
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"error": err.Error(),
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})
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})
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```
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### Custom Not Found Handler
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```go
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k.SetNotFoundHandler(func(ctx *kite.Context) error {
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return ctx.WriteJSON(http.StatusNotFound, map[string]string{
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"error": "route not found",
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})
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})
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```
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### Custom Method Not Allowed Handler
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```go
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k.SetMethodNotAllowedHandler(func(ctx *kite.Context) error {
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return ctx.WriteJSON(http.StatusMethodNotAllowed, map[string]string{
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"error": "method not allowed",
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})
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})
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```
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## Server Configuration
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```go
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k := kite.New()
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k.SetServerReadTimeout(10 * time.Second) // default: 10s
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k.SetServerWriteTimeout(30 * time.Second) // default: 30s
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k.SetServerIdleTimeout(60 * time.Second) // default: 60s
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k.SetServerShutdownTimeout(30 * time.Second) // default: 30s
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```
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## Graceful Shutdown
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`Start()` blocks until `SIGINT` or `SIGTERM` is received, then waits for all in-flight requests to finish before exiting. This maps directly to how Docker, Kubernetes, and systemd stop processes.
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```go
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if err := k.Start("localhost:8080"); err != nil {
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log.Fatal(err)
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}
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```
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## TLS
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Use `StartTLS` instead of `Start` and provide your certificate and key files:
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```go
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if err := k.StartTLS("localhost:443", "cert.pem", "key.pem"); err != nil {
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log.Fatal(err)
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}
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```
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For local development you can generate a self-signed certificate:
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```bash
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openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes
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```
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For production, use a certificate from a trusted CA. [Caddy](https://caddyserver.com) and [Nginx](https://nginx.org) are both good options as a reverse proxy if you prefer to terminate TLS outside the application.
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## Performance
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Benchmarked on a MacBook Pro. Each scenario ran for 30 seconds per concurrency level with a 5 second warmup.
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### Hello World (string + logger middleware)
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| Concurrency | RPS | Avg Latency | Avg CPU | Avg RAM |
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| ----------- | ----------- | ----------- | --------- | ----------- |
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| 1 | 22,076 | 0.04ms | 31.0% | 20.95MB |
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| 10 | 79,567 | 0.12ms | 86.2% | 24.01MB |
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| 25 | 95,066 | 0.25ms | 88.8% | 24.54MB |
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| 50 | 100,283 | 0.47ms | 91.5% | 27.81MB |
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| 100 | 113,956 | 0.83ms | 93.5% | 30.91MB |
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| 250 | 128,858 | 1.81ms | 97.0% | 43.42MB |
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| **500** | **132,760** | **3.45ms** | **91.9%** | **58.20MB** |
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| 1000 | 131,101 | 6.92ms | 98.6% | 83.23MB |
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```
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RPS
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140k │ ▓▓▓▓ ████
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120k │ ▓▓▓▓ ████ ████
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100k │ ████ ████ ████ ████ ████ ████
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80k │ ████ ████ ████ ████ ████ ████ ████
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60k │ ████ ████ ████ ████ ████ ████ ████
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40k │ ████ ████ ████ ████ ████ ████ ████ ████
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20k │ ████ ████ ████ ████ ████ ████ ████ ████
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└──────────────────────────────────────────────▶
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1 10 25 50 100 250 500 1000
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Concurrency
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```
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> **Sweet spot: 250–500 workers** — RPS plateaus around 132k while latency stays under 4ms.
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---
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### SQLite Counter (UPDATE + SELECT + JSON response)
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| Concurrency | RPS | Avg Latency | Avg CPU | Avg RAM |
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| ----------- | ----- | ----------- | ------- | -------- |
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| 1 | 4,983 | 0.20ms | 19.9% | 83.34MB |
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| 10 | 4,728 | 2.04ms | 19.4% | 86.30MB |
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| 25 | 4,433 | 5.50ms | 19.0% | 88.81MB |
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| 50 | 2,913 | 15.98ms | 29.5% | 61.68MB |
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| 100 | 2,139 | 38.61ms | 20.8% | 71.38MB |
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| 250 | 628 | 189.88ms | 18.0% | 102.66MB |
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| 500 | 257 | 548.91ms | 11.9% | 164.40MB |
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| 1000 | 130 | 853.20ms | 9.4% | 288.71MB |
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```
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RPS
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5.0k │ ████ ████
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4.0k │ ████ ████ ████
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3.0k │ ████ ████ ████ ████
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2.0k │ ████ ████ ████ ████ ████
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1.0k │ ████ ████ ████ ████ ████ ████
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500 │ ████ ████ ████ ████ ████ ████ ████
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100 │ ████ ████ ████ ████ ████ ████ ████ ████
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└──────────────────────────────────────────────▶
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1 10 25 50 100 250 500 1000
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Concurrency
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```
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> **Sweet spot: 1 worker** — SQLite's single-writer model means concurrency hurts. RPS drops sharply beyond 10 workers as write contention builds up. This is a SQLite limitation, not a kite limitation — a Postgres or MySQL backend would scale horizontally.
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---
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### Key Takeaways
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- **Pure HTTP throughput** peaks at ~132k RPS with negligible RAM usage (~58MB at peak)
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- **Middleware overhead** (logger) adds virtually no cost
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- **RAM scales linearly** with concurrency — roughly 50–85 bytes per idle goroutine
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- **CPU saturates around 250 workers** for in-memory workloads — beyond that, latency grows but RPS flattens
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- **Database workloads** are bottlenecked by the DB, not the framework — kite's overhead is not the limiting factor
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## License
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MIT
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