handle SIGHUP, restart camli from wizard

Change-Id: I9856e49b9c4d76dc3bed1827594451349d4f5810

pkg/osutil/restart_unix.go

@@ -0,0 +1,17 @@
+// +build linux darwin
+
+// TODO(mpl): Copyright in next CL.
+
+package osutil
+
+import (
+	"os"
+	"syscall"
+)
+
+// restartProcess returns an error if things couldn't be
+// restarted.  On success, this function never returns
+// because the process becomes the new process.
+func RestartProcess() error {
+	return syscall.Exec(os.Args[0], os.Args, os.Environ())
+}

pkg/osutil/restart_windows.go

@@ -0,0 +1,17 @@
+// +build windows
+
+// TODO(mpl): Copyright in next CL.
+
+package osutil
+
+import (
+	"log"
+)
+
+// restartProcess returns an error if things couldn't be
+// restarted.  On success, this function never returns
+// because the process becomes the new process.
+func RestartProcess() error {
+	log.Print("RestartProcess not implemented on windows")
+	return nil
+}

pkg/server/wizard-html.go

@@ -30,6 +30,10 @@ const topWizard =`
 
 const bottomWizard =`
 <p> <a href="/">Back</a> </p>
+<p>
+	<form id="Restart" name="Restart" action="restartCamli" method="post">
+	<input type="submit" form="Restart" value="RestartCamli"></form>
+</p>
 </body>
 </html>
 `

pkg/server/wizard.go

@@ -20,6 +20,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"html/template"
+	"log"
 	"net/http"
 	"os"
 	"reflect"
@@ -167,11 +168,6 @@ func rewriteConfig(config *jsonconfig.Obj, configfile string) error {
 }
 
 func handleSetupChange(req *http.Request, rw http.ResponseWriter) {
-	err := req.ParseMultipartForm(10e6)
-	if err != nil {
-		httputil.ServerError(rw, err)
-		return
-	}
 	hilevelConf, err := jsonconfig.ReadFile(osutil.UserServerConfigPath())
 	if err != nil {
 		httputil.ServerError(rw, err)
@@ -257,8 +253,21 @@ func (sh *SetupHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		return
 	}
 	if req.Method == "POST" {
-		handleSetupChange(req, rw)
-		return
+		err := req.ParseMultipartForm(10e6)
+		if err != nil {
+			httputil.ServerError(rw, err)
+			return
+		}
+		if len(req.Form) > 0 {
+			handleSetupChange(req, rw)
+			return
+		}
+		if strings.Contains(req.URL.Path, "restartCamli") {
+			err = osutil.RestartProcess()
+			if err != nil {
+				log.Fatal("Failed to restart: " + err.Error())
+			}
+		}
 	}
 
 	sendWizard(req, rw, false)

server/camlistored/camlistored.go

@@ -29,9 +29,11 @@ import (
 	"math/big"
 	"net"
 	"os"
+	"os/signal"
 	"path/filepath"
 	"runtime"
 	"strings"
+	"syscall"
 	"time"
 
 	"camlistore.org/pkg/jsonsign"
@@ -266,6 +268,28 @@ func setupTLS(ws *webserver.Server, config *serverconfig.Config, listen string)
 	ws.SetTLS(cert, key)
 }
 
+func handleSignals() {
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGHUP)
+	for {
+		sig := <-c
+		sysSig, ok := sig.(syscall.Signal)
+		if !ok {
+			log.Fatal("Not a unix signal")
+		}
+		switch sysSig {
+		case syscall.SIGHUP:
+			log.Print("SIGHUP: restarting camli")
+			err := osutil.RestartProcess()
+			if err != nil {
+				log.Fatal("Failed to restart: " + err.Error())
+			}
+		default:
+			log.Fatal("Received another signal, should not happen.")
+		}
+	}
+}
+
 func main() {
 	flag.Parse()
 
@@ -320,5 +344,6 @@ func main() {
 			}
 		}()
 	}
-	ws.Serve()
+	go ws.Serve()
+	handleSignals()
 }