forked from onsi/grace
/
main.go
133 lines (117 loc) · 3.12 KB
/
main.go
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package main
import (
"flag"
"fmt"
"net/http"
"os"
"os/signal"
"syscall"
"time"
"github.com/onsi/grace/handlers"
"github.com/onsi/grace/helpers"
"github.com/onsi/grace/routes"
"github.com/pivotal-golang/lager"
"github.com/tedsuo/ifrit"
"github.com/tedsuo/ifrit/grouper"
"github.com/tedsuo/ifrit/http_server"
"github.com/tedsuo/rata"
)
func main() {
var chatty bool
var upFile string
var exitAfter, startAfter time.Duration
var exitAfterCode int
var catchTerminate bool
var attachToHostname bool
flag.BoolVar(&chatty, "chatty", false, "make grace chatty")
flag.StringVar(&upFile, "upFile", "", "a file to write to (lives under /tmp)")
flag.DurationVar(&exitAfter, "exitAfter", 0, "if set, grace will exit after this duration")
flag.IntVar(&exitAfterCode, "exitAfterCode", 0, "exit code to emit with exitAfter")
flag.BoolVar(&catchTerminate, "catchTerminate", false, "make grace catch SIGTERM")
flag.DurationVar(&startAfter, "startAfter", 0, "time to wait before starting")
flag.BoolVar(&attachToHostname, "attachToHostname", false, "make grace attach to hostname:port instead of :port")
flag.Parse()
logger := lager.NewLogger("grace")
logger.RegisterSink(lager.NewWriterSink(os.Stdout, lager.DEBUG))
port := os.Getenv("PORT")
if port == "" {
port = "8080"
}
if startAfter > 0 {
logger.Info("grace-is-sleeping-before-coming-up")
time.Sleep(startAfter)
}
logger.Info("hello", lager.Data{"port": port})
handler, err := rata.NewRouter(routes.Routes, handlers.New(logger))
if err != nil {
logger.Fatal("router.creation.failed", err)
}
if chatty {
index, err := helpers.FetchIndex()
go func() {
t := time.NewTicker(time.Second)
for {
<-t.C
if err != nil {
fmt.Fprintf(os.Stderr, "Failed to fetch index: %s\n", err.Error())
} else {
fmt.Printf("This is Grace on index: %d\n", index)
}
}
}()
}
if upFile != "" {
f, err := os.Create("/tmp/" + upFile)
if err != nil {
logger.Fatal("upfile.creation.failed", err)
}
_, err = f.WriteString("Grace is up")
if err != nil {
logger.Fatal("upfile.creation.failed", err)
}
}
if exitAfter != 0 {
go func() {
time.Sleep(exitAfter)
fmt.Println("timebomb... farewell")
os.Exit(exitAfterCode)
}()
}
if catchTerminate {
go func() {
fmt.Println("Will Catch SIGTERM")
c := make(chan os.Signal, 1)
signal.Notify(c, syscall.SIGTERM)
<-c
t := time.NewTicker(time.Second)
for {
fmt.Println("Caught SIGTERM")
<-t.C
}
}()
}
addr := ":" + port
secondary := ":9999"
if attachToHostname {
hostname, err := os.Hostname()
if err != nil {
logger.Fatal("couldn't get hostname", err)
}
addr = hostname + ":" + port
secondary = hostname + ":9999"
}
fmt.Printf("Grace is listening on %s\n", addr)
server := ifrit.Invoke(grouper.NewOrdered(os.Interrupt,
grouper.Members{
{"primary", http_server.New(addr, handler)},
{"secondary", http_server.New(secondary, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
fmt.Fprint(w, "grace side-channel")
}))},
},
))
err = <-server.Wait()
if err != nil {
logger.Error("farewell", err)
}
logger.Info("farewell")
}