Go语言如何优雅实现灰度发布

gray-release/
├── main.go
├── version_router.go

package main
import (
    "fmt"
    "net/http"
)
func versionRouter(w http.ResponseWriter, r *http.Request) {
    version := r.Header.Get("X-App-Version")
    switch version {
    case "v2":
        handleV2(w, r)
    default:
        handleV1(w, r)
    }
}
func handleV1(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintln(w, "Welcome to Version 1 - Stable!")
}
func handleV2(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintln(w, " Welcome to Version 2 - Beta (Gray Release)!")
}

package main
import (
    "log"
    "net/http"
)
func main() {
    http.HandleFunc("/", versionRouter)
    log.Println("🔧 Server running on :8080")
    log.Fatal(http.ListenAndServe(":8080", nil))
}

go run main.go version_router.go

curl http://localhost:8080/
# 输出:  Welcome to Version 1 - Stable!

curl -H "X-App-Version: v2" http://localhost:8080/
# 输出: Welcome to Version 2 - Beta (Gray Release)!

func versionRouter(w http.ResponseWriter, r *http.Request) {
    userID := r.Header.Get("X-User-ID")
    // 10% 的用户被灰度
    if isGrayUser(userID) {
        handleV2(w, r)
        return
    }
    handleV1(w, r)
}
func isGrayUser(userID string) bool {
    hash := fnv.New32a()
    hash.Write([]byte(userID))
    return hash.Sum32()%10 == 0
}