via

commit

d5f6909fa5d5d913b417dc8ea92652b552e5f5e0

parent

420c90d5905eafa8b13303d6b01b82b7b4819c9d

Author

Tobias Bengfort <tobias.bengfort@posteo.de>

Date

2024-02-11 17:37

graceful shutdown

- call Shutdown to close connections before exit
- exit with status 0 on shutdown
- call Shutdown in the main thread because it blocks while
  ListenAndServe exits immediately
- Shutdown waits for requests to complete. We pass the signal context to
  the server so it derives the request contexts from that. The
  long-running GET request handler already stop on context cancellation.
- unregister signals before shutdown so that a second Ctrl-C will hard-exit

https://dev.to/mokiat/proper-http-shutdown-in-go-3fji
https://erictse.dev/posts/graceful-go-http-server/

Diffstat

1 files changed, 22 insertions, 2 deletions

diff --git a/via.go b/via.go

@@ -1,18 +1,22 @@
    1     1 package main
    2     2 
    3     3 import (
   -1     4 	"context"
    4     5 	"encoding/base64"
    5     6 	"encoding/json"
    6     7 	"flag"
    7     8 	"fmt"
    8     9 	"io/ioutil"
    9    10 	"log"
   -1    11 	"net"
   10    12 	"net/http"
   11    13 	"os"
   -1    14 	"os/signal"
   12    15 	"path"
   13    16 	"strconv"
   14    17 	"strings"
   15    18 	"sync"
   -1    19 	"syscall"
   16    20 	"time"
   17    21 )
   18    22 
@@ -371,6 +375,22 @@ func main() {
  371   375 	http.HandleFunc("/msg/", handler)
  372   376 	http.HandleFunc("/hmsg/", handler)
  373   377 
  374    -1 	log.Printf("Serving on http://%s", addr)
  375    -1 	log.Fatal(http.ListenAndServe(addr, nil))
   -1   378 	ctx, unregisterSignals := signal.NotifyContext(
   -1   379 		context.Background(), os.Interrupt, syscall.SIGTERM,
   -1   380 	)
   -1   381 	ctxFactory := func(l net.Listener) context.Context { return ctx }
   -1   382 	server := &http.Server{Addr: addr, BaseContext: ctxFactory}
   -1   383 
   -1   384 	go func() {
   -1   385 		log.Printf("Serving on http://%s", addr)
   -1   386 		err := server.ListenAndServe()
   -1   387 		if err != http.ErrServerClosed {
   -1   388 			log.Fatal(err)
   -1   389 		}
   -1   390 	}()
   -1   391 
   -1   392 	<-ctx.Done()
   -1   393 	unregisterSignals()
   -1   394 	log.Println("Shutting down server…")
   -1   395 	server.Shutdown(context.Background())
  376   396 }