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package main
import (
"context"
"fmt"
"log"
"net/http"
"os"
"os/signal"
"syscall"
"time"
"github.com/go-chi/chi/v5"
"github.com/go-chi/chi/v5/middleware"
)
func main() {
// The HTTP Server
server := &http.Server{Addr: "0.0.0.0:3333", Handler: service()}
// Server run context
serverCtx, serverStopCtx := context.WithCancel(context.Background())
// Listen for syscall signals for process to interrupt/quit
sig := make(chan os.Signal, 1)
signal.Notify(sig, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
go func() {
<-sig
// Shutdown signal with grace period of 30 seconds
shutdownCtx, _ := context.WithTimeout(serverCtx, 30*time.Second)
go func() {
<-shutdownCtx.Done()
if shutdownCtx.Err() == context.DeadlineExceeded {
log.Fatal("graceful shutdown timed out.. forcing exit.")
}
}()
// Trigger graceful shutdown
err := server.Shutdown(shutdownCtx)
if err != nil {
log.Fatal(err)
}
serverStopCtx()
}()
// Run the server
err := server.ListenAndServe()
if err != nil && err != http.ErrServerClosed {
log.Fatal(err)
}
// Wait for server context to be stopped
<-serverCtx.Done()
}
func service() http.Handler {
r := chi.NewRouter()
r.Use(middleware.RequestID)
r.Use(middleware.Logger)
r.Get("/", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("sup"))
})
r.Get("/slow", func(w http.ResponseWriter, r *http.Request) {
// Simulates some hard work.
//
// We want this handler to complete successfully during a shutdown signal,
// so consider the work here as some background routine to fetch a long running
// search query to find as many results as possible, but, instead we cut it short
// and respond with what we have so far. How a shutdown is handled is entirely
// up to the developer, as some code blocks are preemptible, and others are not.
time.Sleep(5 * time.Second)
w.Write([]byte(fmt.Sprintf("all done.\n")))
})
return r
}
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