A non-intrusive package, adding a graceful shutdown to Go's HTTP server, by utilizing http.Server's built-in Shutdown() method, with zero dependencies.
Assume the following code in a file called simple.go:
package main import ( "fmt" "log" "net/http" "time" "github.com/pseidemann/finish" ) func main() { http.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) { time.Sleep(5 * time.Second) fmt.Fprintln(w, "world") }) srv := &http.Server{Addr: "localhost:8080"} fin := finish.New() fin.Add(srv) go func() { if err := srv.ListenAndServe(); err != http.ErrServerClosed { log.Fatal(err) } }() fin.Wait() }Now execute that file:
$ go run simple.goDo a HTTP GET request:
$ curl localhost:8080/helloThis will print "world" after 5 seconds.
When the server is terminated with pressing Ctrl+C or kill, while /hello is loading, finish will wait until the request was handled, before the server gets killed.
The output will look like this:
2038/01/19 03:14:08 finish: shutdown signal received 2038/01/19 03:14:08 finish: shutting down server ... 2038/01/19 03:14:11 finish: server closed How to change the default timeout of 10 seconds.
package main import ( "fmt" "log" "net/http" "time" "github.com/pseidemann/finish" ) func main() { http.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) { time.Sleep(5 * time.Second) fmt.Fprintln(w, "world") }) srv := &http.Server{Addr: "localhost:8080"} fin := &finish.Finisher{Timeout: 30 * time.Second} fin.Add(srv) go func() { if err := srv.ListenAndServe(); err != http.ErrServerClosed { log.Fatal(err) } }() fin.Wait() }In this example the timeout is set to 30 seconds.
How to change the default logger.
package main import ( "fmt" "log" "net/http" "time" "github.com/pseidemann/finish" "github.com/sirupsen/logrus" ) func main() { http.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) { time.Sleep(5 * time.Second) fmt.Fprintln(w, "world") }) srv := &http.Server{Addr: "localhost:8080"} fin := &finish.Finisher{Log: logrus.StandardLogger()} fin.Add(srv) go func() { if err := srv.ListenAndServe(); err != http.ErrServerClosed { log.Fatal(err) } }() fin.Wait() }In this example, logrus is configured for logging.
How to change the default signals (SIGINT, SIGTERM) which will initiate the shutdown.
package main import ( "fmt" "log" "net/http" "syscall" "time" "github.com/pseidemann/finish" ) func main() { http.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) { time.Sleep(5 * time.Second) fmt.Fprintln(w, "world") }) srv := &http.Server{Addr: "localhost:8080"} fin := &finish.Finisher{Signals: append(finish.DefaultSignals, syscall.SIGHUP)} fin.Add(srv) go func() { if err := srv.ListenAndServe(); err != http.ErrServerClosed { log.Fatal(err) } }() fin.Wait() }In this example, finish will not only catch the default signals SIGINT and SIGTERM but also the signal SIGHUP.
This example uses a custom router httprouter, a different timeout, a custom logger logrus, custom signals, options for Add() and multiple servers.
package main import ( "fmt" "log" "net/http" "syscall" "time" "github.com/julienschmidt/httprouter" "github.com/pseidemann/finish" "github.com/sirupsen/logrus" ) func main() { routerPub := httprouter.New() routerPub.HandlerFunc("GET", "/hello", func(w http.ResponseWriter, r *http.Request) { time.Sleep(5 * time.Second) fmt.Fprintln(w, "world") }) routerInt := httprouter.New() routerInt.HandlerFunc("GET", "/status", func(w http.ResponseWriter, r *http.Request) { fmt.Fprintln(w, "ok") }) srvPub := &http.Server{Addr: "localhost:8080", Handler: routerPub} srvInt := &http.Server{Addr: "localhost:3000", Handler: routerInt} fin := &finish.Finisher{ Timeout: 30 * time.Second, Log: logrus.StandardLogger(), Signals: append(finish.DefaultSignals, syscall.SIGHUP), } fin.Add(srvPub, finish.WithName("public server")) fin.Add(srvInt, finish.WithName("internal server"), finish.WithTimeout(5*time.Second)) go func() { logrus.Infof("starting public server at %s", srvPub.Addr) if err := srvPub.ListenAndServe(); err != http.ErrServerClosed { log.Fatal(err) } }() go func() { logrus.Infof("starting internal server at %s", srvInt.Addr) if err := srvInt.ListenAndServe(); err != http.ErrServerClosed { log.Fatal(err) } }() fin.Wait() }