sahd;ljasl;dkj

.gitignore

@@ -0,0 +1,3 @@
+/hnctl
+/router
+/wrench

cli/cli.go

@@ -0,0 +1,81 @@
+// Package cli provides utilities for writing command line utilities that
+// interact with services.
+package cli
+
+import "os"
+import "fmt"
+import "flag"
+import "os/user"
+import "strings"
+import "strconv"
+import "path/filepath"
+
+// Sayf is like Printf, but prints the program name before the message. This is
+// used for printing messages and errors.
+func Sayf (format string, values ...any) {
+	Printf(os.Args[0] + ": " + format, values...)
+}
+
+// Printf prints to stderr.
+func Printf (format string, values ...any) {
+	fmt.Fprintf(flag.CommandLine.Output(), format, values...)
+}
+
+// ServiceUser returns the system user that corresponds to the given service
+// name. This is not necissarily equivalent Hnakra user, although it is good
+// practice to have a 1:1 correspondance between them.
+func ServiceUser (service string) string {
+	return "hn-" + strings.ToLower(service)
+}
+
+// DataDir returns the standard Hnakra data directory.
+func DataDir () string {
+	return "/var/hnakra"
+}
+
+// ServiceDir returns the standard data directory of a service.
+func ServiceDir (service string) string {
+	return filepath.Join(DataDir(), "services", ServiceUser(service))
+}
+
+// NeedRoot halts the program and displays an error if it is not being run as
+// root. This should be called whenever an operation takes place that requires
+// root privelages.
+func NeedRoot() {
+	uid := os.Getuid()
+	if uid != 0 {
+		Sayf("this utility must be run as root")
+		os.Exit(1)
+	}
+}
+
+// MkdirFor makes a directory makes the specified directory (if it doesnt
+// already exist) and gives ownership of it to the specified uid and gid.
+func MkdirFor (directory string, uid, gid int) error {
+	err := os.MkdirAll(directory, 0755)
+	if err != nil { return err }
+	err = os.Chmod(directory, 0770)
+	if err != nil { return err }
+	err = os.Chown(directory, uid, gid)
+	if err != nil { return err }
+
+	return nil
+}
+
+// LookupUID returns the uid and gid of the given username, if it exists.
+func LookupUID (name string) (uid, gid uint32, err error) {
+	user, err := user.Lookup(name)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	puid, err := strconv.Atoi(user.Uid)
+	if err != nil {
+		return 0, 0, err
+	}
+	pgid, err := strconv.Atoi(user.Gid)
+	if err != nil {
+		return 0, 0, err
+	}
+	return uint32(puid), uint32(pgid), nil
+}

cmd/hn-router/main.go

@@ -4,13 +4,14 @@ import "io"
 import "os"
 import "log"
 import "time"
-import "hnakra/rotate"
 import "hnakra/router"
+import "hnakra/rotate"
+import "hnakra/daemon"
 import "hnakra/routines"
 import "hnakra/router/rcon"
 import "hnakra/router/config"
-import "hnakra/cmd/router/srvhttps"
-import "hnakra/cmd/router/srvhnakra"
+import "hnakra/cmd/hn-router/srvhttps"
+import "hnakra/cmd/hn-router/srvhnakra"
 
 const banner = "\n" +
 "            -=\\\n" +
@@ -59,10 +60,10 @@ func main () {
 	manager   := routines.Manager { RestartDeadline: time.Second * 8 }
 	rout      := router.New(conf)
 	srvhnakra := &srvhnakra.Server { Config: conf, Router:  rout }
-	manager.Append(srvhnakra.ListenAndServe)
+	manager.Append(srvhnakra)
 	if conf.HTTPSEnable() {
 		srvhttps := &srvhttps.Server { Config: conf, Handler: rout }
-		manager.Append(srvhttps.ListenAndServe)
+		manager.Append(srvhttps)
 	}
 
 	// set up rcon
@@ -74,12 +75,19 @@ func main () {
 		log.SetOutput(originalWriter)
 	}
 
+	// be a daemon
+	daemon.ShutdownOnSigint(&manager)
+	pidfile := daemon.PidFile(os.Getenv("HNAKRA_PIDFILE"))
+	if !pidfile.Empty() {
+		err := pidfile.Start()
+		if err != nil { log.Println("!!! could not write pid:", err) }
+		defer func () {
+			err := pidfile.Close()
+			if err != nil { log.Println("!!! could not delete pidfile:", err) }
+		} ()
+	}
+
 	// run servers
 	err = manager.Run()
 	if err != nil { log.Println("XXX", err) }
 }
-
-func httpsRoutine (server *srvhttps.Server) {
-	err := server.ListenAndServe()
-	if err != nil { log.Println("XXX", err) }
-}

cmd/hn-router/srvhnakra/hnakra.go

@@ -11,24 +11,34 @@ type Server struct {
 	underlying net.Listener
 	Config     config.Config
 	Router     *router.Router
+
+	running bool
 }
 
-func (server *Server) ListenAndServe () (err error) {
+func (server *Server) Run () (err error) {
 	server.underlying, err = tls.Listen (
 		"tcp", fmt.Sprint(":", server.Config.RouterPort()),
 		config.TLSConfigFor(server.Config))
 	if err != nil { return err }
-	
+
+	server.running = true
 	log.Println(".// router on", server.underlying.Addr())
 
 	for {
 		conn, err := server.underlying.Accept()
-		if err != nil { return err }
+		if err != nil {
+			if server.running {
+				return err
+			} else {
+				return nil
+			}
+		}
 		log.Println("-=E incoming connection from", conn.RemoteAddr())
 		server.Router.Accept(conn)
 	}
 }
 
-func (server *Server) Close () error {
+func (server *Server) Shutdown () error {
+	server.running = false
 	return server.underlying.Close()
 }

cmd/hn-router/srvhttps/https.go

@@ -9,9 +9,11 @@ type Server struct {
 	underlying *http.Server
 	Config      config.Config
 	Handler     http.Handler
+	
+	running bool
 }
 
-func (server *Server) ListenAndServe () error {
+func (server *Server) Run () error {
 	server.underlying = &http.Server {
 		Addr:              fmt.Sprint(":", server.Config.HTTPSPort()),
 		// ReadHeaderTimeout: timeoutReadHeader * time.Second,
@@ -22,10 +24,17 @@ func (server *Server) ListenAndServe () error {
 		Handler:           server.Handler,
 	}
 
+	server.running = true
 	log.Println(".// https on", server.underlying.Addr)
-	return server.underlying.ListenAndServeTLS("", "")
+	err := server.underlying.ListenAndServeTLS("", "")
+	if server.running {
+		return err
+	} else {
+		return nil
+	}
 }
 
-func (server *Server) Close () error {
+func (server *Server) Shutdown () error {
+	server.running = false
 	return server.underlying.Close()
 }

cmd/hnctl/main.go

@@ -0,0 +1,140 @@
+package main
+
+import "os"
+import "fmt"
+import "time"
+import "flag"
+import "os/exec"
+import "hnakra/cli"
+import "path/filepath"
+import "hnakra/cmd/hnctl/spawn"
+
+func main () {
+	flag.Usage = func () {
+		out := flag.CommandLine.Output()
+		fmt.Fprintf(out, "Usage of %s:\n", os.Args[0])
+		fmt.Fprintf(out, "  start\n")
+		fmt.Fprintf(out, "    Start a service\n")
+		fmt.Fprintf(out, "  stop\n")
+		fmt.Fprintf(out, "    Stop a service\n")
+		fmt.Fprintf(out, "  restart\n")
+		fmt.Fprintf(out, "    Start and then stop a service\n")
+		os.Exit(1)
+	}
+
+	// define commands
+	startCommand := flag.NewFlagSet("start", flag.ExitOnError)
+	startService := startCommand.String("s", "router", "Service to start")
+	
+	stopCommand := flag.NewFlagSet("stop", flag.ExitOnError)
+	stopService := stopCommand.String("s", "router", "Service to stop")
+	
+	restartCommand := flag.NewFlagSet("restart", flag.ExitOnError)
+	restartService := restartCommand.String("s", "router", "Service to restart")
+	
+	flag.Parse()
+
+	// execute correct command
+	if len(os.Args) < 2 {
+		flag.Usage()
+		os.Exit(1)
+	}
+	subCommandArgs := os.Args[2:]
+	switch os.Args[1] {
+	case "start":
+		startCommand.Parse(subCommandArgs)
+		execStart(*startService)
+	case "stop":
+		stopCommand.Parse(subCommandArgs)
+		execStop(*stopService)
+	case "restart":
+		restartCommand.Parse(subCommandArgs)
+		execStop(*restartService)
+		execStart(*restartService)
+	}
+}
+
+func execStart (service string) {
+	fullName := cli.ServiceUser(service)
+	cli.NeedRoot()
+	
+	pid, err := spawn.PidOf(fullName)
+	if err == nil && spawn.Running(pid) {
+		cli.Sayf("service is already running\n")
+		return
+	}
+	
+	uid, gid, err := cli.LookupUID(fullName)
+	if err != nil {
+		cli.Sayf("cannot start service: %v\n", err)
+		os.Exit(1)
+	}
+	
+	path, err := exec.LookPath(fullName)
+	if err != nil {
+		cli.Sayf("cannot start service: %v\n", err)
+		os.Exit(1)
+	}
+
+	logDir := filepath.Join("/var/log/", fullName)
+	env := append(os.Environ(), "HNAKRA_LOG_DIR=" + logDir)
+	err = cli.MkdirFor(logDir, int(uid), int(gid))
+	if err != nil {
+		cli.Sayf("cannot start service: %v\n", err)
+		os.Exit(1)
+	}
+
+	// prepare pidfile. the service will be responsible for actually writing
+	// to it
+	err = ensurePidFile(spawn.PidFile(fullName), int(uid), int(gid))
+	if err != nil {
+		cli.Sayf("cannot start service: %v\n", err)
+		os.Exit(1)
+	}
+
+	// spawn the service
+	pid, err = spawn.Spawn(path, uid, gid, env)
+	if err != nil {
+		cli.Sayf("cannot start service: %v\n", err)
+		os.Exit(1)
+	}
+	
+	fmt.Println(pid)
+}
+
+func execStop (service string) {
+	fullName := cli.ServiceUser(service)
+	cli.NeedRoot()
+	
+	pid, err := spawn.PidOf(fullName)
+	if err != nil || !spawn.Running(pid) {
+		cli.Sayf("service is not running\n")
+		return
+	}
+
+	process, err := os.FindProcess(pid)
+	if err != nil {
+		cli.Sayf("service is not running\n")
+		return
+	}
+
+	err = spawn.KillAndWait(process, 16 * time.Second)
+	if err != nil {
+		cli.Sayf("could not stop service: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func ensurePidFile (file string, uid, gid int) error {
+	pidFile, err := os.Create(file)
+	if err != nil { return err }
+	err = pidFile.Close()
+	if err != nil { return err }
+	
+	err = os.Chmod(file, 0660)
+	if err != nil { return err }
+	err = os.Chown(file, uid, gid)
+	if err != nil { return err }
+
+	return nil
+}

cmd/hnctl/spawn/spawn.go

@@ -0,0 +1,113 @@
+// Package spawn provides utilities for daemonizing services.
+package spawn
+
+import "os"
+import "fmt"
+import "time"
+import "errors"
+import "syscall"
+import "strconv"
+import "path/filepath"
+
+// Spawn spawns a process in the background and returns its PID.
+func Spawn (path string, uid, gid uint32, env []string, args ...string) (pid int, err error) {
+	cred := &syscall.Credential{
+		Uid:         uid,
+		Gid:         gid,
+		Groups:      []uint32{},
+		NoSetGroups: false,
+	}
+
+	// the Noctty flag is used to detach the process from parent tty
+	sysproc := &syscall.SysProcAttr{
+		Credential: cred,
+		Noctty:     true,
+	}
+	attr := os.ProcAttr{
+		Dir: ".",
+		Env: os.Environ(),
+		Files: []*os.File{
+			os.Stdin,
+			nil,
+			nil,
+		},
+		Sys: sysproc,
+	}
+
+	process, err := os.StartProcess(path, args, &attr)
+	if err != nil {
+		return 0, err
+	}
+
+	// Release() is what actually detatches the process and places it under
+	// init
+	return process.Pid, process.Release()
+}
+
+// PidFile returns the path of a pidfile under the specified name. More
+// specifically, it returns `/run/<name>.pid`.
+func PidFile (name string) string {
+	return filepath.Join("/run/", name + ".pid")
+}
+
+// PidOf returns the PID stored in the pidfile of the given name as defined by
+// PidFile.
+func PidOf (name string) (pid int, err error) {
+	content, err := os.ReadFile(PidFile(name))
+	if err != nil {
+		return 0, err
+	}
+	pid, err = strconv.Atoi(string(content))
+	if err != nil {
+		return 0, err
+	}
+	return pid, nil
+}
+
+// Running returns whether or not a process with the given PID is running.
+func Running (pid int) bool {
+	directoryInfo, err := os.Stat("/proc/")
+	if os.IsNotExist(err) || !directoryInfo.IsDir() {
+		// if /proc/ does not exist, fallback to sending a signal
+		process, err := os.FindProcess(pid)
+		if err != nil {
+			return false
+		}
+		err = process.Signal(syscall.Signal(0))
+		if err != nil {
+			return false
+		}
+	} else {
+		// if /proc/ exists, see if the process's directory exists there
+		_, err = os.Stat("/proc/" + strconv.Itoa(pid))
+		if err != nil {
+			return false
+		}
+	}
+
+	return true
+}
+
+// KillAndWait kills a process and waits for it to finish, with a timeout. If
+// the timeout is zero, it will wait indefinetly. This function will poll every
+// 100 milliseconds to see if the process has finished.
+func KillAndWait (process *os.Process, timeout time.Duration) error {
+	pid := process.Pid
+	err := process.Kill()
+	if err != nil {
+		return err
+	}
+
+	// wait for the process to exit, with a timeout
+	timeoutPoint := time.Now()
+	for timeout == 0 || time.Since(timeoutPoint) < 16 * time.Second {
+		if !Running(pid) {
+			return nil
+		}
+		
+		time.Sleep(100 * time.Millisecond)
+	}
+
+	return errors.New(fmt.Sprintf (
+		"timeout exceeded while waiting for process %d to finish", pid))
+}

cmd/wrench/main.go

@@ -6,24 +6,14 @@ import "flag"
 import "strconv"
 import "os/exec"
 import "os/user"
+import "hnakra/cli"
 import "path/filepath"
 import "golang.org/x/crypto/bcrypt"
 
-func printErr (format string, values ...any) {
-	fmt.Fprintf (
-		flag.CommandLine.Output(),
-		os.Args[0] + ": " + format + "\n",
-		values...)
-}
-
-func serviceUser (service string) string {
-	return "hn-" + service
-}
-
 func tryCommand (cmd *exec.Cmd, failReason string) {
 	output, err := cmd.CombinedOutput()
 	if err != nil {
-		printErr("%s: %s", failReason, string(output))
+		cli.Sayf("%s: %s\n", failReason, string(output))
 		os.Exit(1)
 	}
 }
@@ -31,13 +21,13 @@ func tryCommand (cmd *exec.Cmd, failReason string) {
 func ownOne (path string, uid, gid int) {
 	file, err := os.Stat(path)
 	if err != nil {
-		printErr("could not stat %s: %v", path, err)
+		cli.Sayf("could not stat %s: %v\n", path, err)
 		return
 	}
 
 	err = os.Chown(path, uid, gid)
 	if err != nil {
-		printErr("could not change ownership of %s: %v", path, err)
+		cli.Sayf("could not change ownership of %s: %v\n", path, err)
 		return
 	}
 
@@ -47,7 +37,7 @@ func ownOne (path string, uid, gid int) {
 		err = os.Chmod(path, 0660)
 	}
 	if err != nil {
-		printErr("could not change mode of %s: %v", path, err)
+		cli.Sayf("could not change mode of %s: %v\n", path, err)
 		return
 	}
 }
@@ -55,23 +45,22 @@ func ownOne (path string, uid, gid int) {
 func main () {
 	user, err := user.Current()
 	if err != nil {
-		printErr("could not get username %v", err)
+		cli.Sayf("could not get username %v\n", err)
 		os.Exit(1)
 	}
 
 	flag.Usage = func () {
-		out := flag.CommandLine.Output()
-		fmt.Fprintf(out, "Usage of %s:\n", os.Args[0])
-		fmt.Fprintf(out, "  hash\n")
-		fmt.Fprintf(out, "    Generate a bcrypt hash of a key\n")
-		fmt.Fprintf(out, "  adduser\n")
-		fmt.Fprintf(out, "    Add a system user to run a service as\n")
-		fmt.Fprintf(out, "  deluser\n")
-		fmt.Fprintf(out, "    Remove a user added with adduser\n")
-		fmt.Fprintf(out, "  auth\n")
-		fmt.Fprintf(out, "    Authorize a system user to access a service's files\n")
-		fmt.Fprintf(out, "  own\n")
-		fmt.Fprintf(out, "    Give ownership of a file to a service\n")
+		cli.Printf("Usage of %s:\n", os.Args[0])
+		cli.Printf("  hash\n")
+		cli.Printf("    Generate a bcrypt hash of a key\n")
+		cli.Printf("  adduser\n")
+		cli.Printf("    Add a system user to run a service as\n")
+		cli.Printf("  deluser\n")
+		cli.Printf("    Remove a user added with adduser\n")
+		cli.Printf("  auth\n")
+		cli.Printf("    Authorize a system user to access a service's files\n")
+		cli.Printf("  own\n")
+		cli.Printf("    Give ownership of a file to a service\n")
 		os.Exit(1)
 	}
 
@@ -87,6 +76,8 @@ func main () {
 	delUserCommand := flag.NewFlagSet("deluser", flag.ExitOnError)
 	delUserService := delUserCommand.String ("s", "router",
 		"Service to delete the user for")
+	delUserRmData  := delUserCommand.Bool ("D", false,
+		"Whether to remove the service's data directory")
 
 	authCommand := flag.NewFlagSet("auth", flag.ExitOnError)
 	authService := authCommand.String ("s", "router",
@@ -119,7 +110,7 @@ func main () {
 		execAdduser(*addUserService)
 	case "deluser":
 		delUserCommand.Parse(subCommandArgs)
-		execDeluser(*delUserService)
+		execDeluser(*delUserService, *delUserRmData)
 	case "auth":
 		authCommand.Parse(subCommandArgs)
 		execAuth(*authService, *authUser)
@@ -131,22 +122,22 @@ func main () {
 
 func execHash (cost int, key string) {
 	if key == "" {
-		printErr("please specify key text content")
+		cli.Sayf("please specify key text content\n")
 		os.Exit(1)
 	}
 
 	if cost < bcrypt.MinCost {
-		printErr("cost is too low, must be at least %v", bcrypt.MinCost)
+		cli.Sayf("cost is too low, must be at least %v\n", bcrypt.MinCost)
 		os.Exit(1)
 	}
 	if cost > bcrypt.MaxCost {
-		printErr("cost is too hight, can be at most %v", bcrypt.MaxCost)
+		cli.Sayf("cost is too hight, can be at most %v\n", bcrypt.MaxCost)
 		os.Exit(1)
 	}
 
 	hash, err := bcrypt.GenerateFromPassword([]byte(key), cost)
 	if err != nil {
-		printErr("could not hash key: %v", err)
+		cli.Sayf("could not hash key: %v\n", err)
 		os.Exit(1)
 	}
 
@@ -154,60 +145,73 @@ func execHash (cost int, key string) {
 }
 
 func execAdduser (service string) {
-	fullName := serviceUser(service)
+	fullName := cli.ServiceUser(service)
+	dataDir  := cli.ServiceDir(service)
 	
-	// BUSYBOX
-	adduser, err := exec.LookPath("adduser")
-	if err == nil {
+	if adduser, err := exec.LookPath("adduser"); err == nil {
+		// BUSYBOX
 		addgroup, _ := exec.LookPath("addgroup")
 		tryCommand (exec.Command(addgroup, fullName, "-S"),
 			"could not add group")
-		tryCommand (exec.Command(adduser, fullName, "-SHDG", fullName),
+		tryCommand (exec.Command (
+			adduser, fullName, "-SHDG", fullName, "-h", dataDir),
 			"could not add user")
-		return
-	}
-
-	// GNU
-	useradd, err := exec.LookPath("useradd")
-	if err == nil {
+	} else if useradd, err := exec.LookPath("useradd"); err == nil {
+		// GNU
 		tryCommand (exec.Command (
 			useradd, fullName, "-rUM",
-			"--shell", "/sbin/nologin"), "could not add user")
-		return
+			"--shell", "/sbin/nologin",
+			"-d", dataDir), "could not add user")
+	} else {
+		cli.Sayf("could not add user: no command adduser or useradd\n")
+		os.Exit(1)
 	}
 
-	printErr("could not add user: no command adduser or useradd")
-	os.Exit(1)
+	// create data directory
+	uid, gid, err := cli.LookupUID(fullName)
+	if err != nil {
+		cli.Sayf("could not create data dir: %v\n", err)
+		os.Exit(1)
+	}
+	err = cli.MkdirFor(dataDir, int(uid), int(gid))
+	if err != nil {
+		cli.Sayf("could not create data dir: %v\n", err)
+		os.Exit(1)
+	}
 }
 
-func execDeluser (service string) {
-	fullName := serviceUser(service)
+func execDeluser (service string, rmData bool) {
+	fullName := cli.ServiceUser(service)
+	dataDir  := cli.ServiceDir(service)
 	
-	// BUSYBOX
-	deluser, err := exec.LookPath("deluser")
-	if err == nil {
+	if deluser, err := exec.LookPath("deluser"); err == nil {
+		// BUSYBOX
 		tryCommand (exec.Command(deluser, fullName, "--remove-home"),
 			"could not delete user")
-		return
-	}
-
-	// GNU
-	userdel, err := exec.LookPath("userdel")
-	if err == nil {
+	} else if userdel, err := exec.LookPath("userdel"); err == nil {
+		// GNU
 		tryCommand (exec.Command(userdel, fullName, "-r"),
 			"could not delete user")
 		groupdel, _ := exec.LookPath("groupdel")
 		tryCommand (exec.Command(groupdel, fullName),
 			"could not delete group")
-		return
+	} else {
+		cli.Sayf("could not delete user: no command deluser or userdel\n")
+		os.Exit(1)
 	}
 
-	printErr("could not delete user: no command deluser or userdel")
-	os.Exit(1)
+	// delete data directory
+	if rmData {
+		err := os.RemoveAll(dataDir)
+		if err != nil {
+			cli.Sayf("could not delete data dir: %v\n", err)
+			os.Exit(1)
+		}
+	}
 }
 
 func execAuth (service, user string) {
-	fullName := serviceUser(service)
+	fullName := cli.ServiceUser(service)
 	
 	adduser, err := exec.LookPath("adduser")
 	if err == nil {
@@ -224,19 +228,19 @@ func execAuth (service, user string) {
 		return
 	}
 
-	printErr("could not auth user: no command adduser or usermod")
+	cli.Sayf("could not auth user: no command adduser or usermod\n")
 	os.Exit(1)
 }
 
 func execOwn (service, file string, recurse bool) {
-	fullName := serviceUser(service)
+	fullName := cli.ServiceUser(service)
 	
 	userInfo, err := user.Lookup(fullName)
 	uid, _ := strconv.Atoi(userInfo.Uid)
 	gid, _ := strconv.Atoi(userInfo.Gid)
 
 	if err != nil {
-		printErr("could not get user info: %v", err)
+		cli.Sayf("could not get user info: %v\n", err)
 		os.Exit(1)
 	}
 
@@ -251,7 +255,7 @@ func execOwn (service, file string, recurse bool) {
 		err error,
 	) error {
 		if err != nil {
-			printErr("could not traverse filesystem: %v", err)
+			cli.Sayf("could not traverse filesystem: %v\n", err)
 			return nil
 		}
 
@@ -260,7 +264,7 @@ func execOwn (service, file string, recurse bool) {
 	})
 
 	if err != nil {
-		printErr("could not traverse filesystem: %v", err)
+		cli.Sayf("could not traverse filesystem: %v\n", err)
 		os.Exit(1)
 	}
 }

daemon/daemon.go

@@ -0,0 +1,50 @@
+// Package daemon provides utilities for daemons.
+package daemon
+
+import "io"
+import "os"
+import "syscall"
+import "strconv"
+import "os/signal"
+
+// PidFile is a string that contains a path to a pidfile.
+type PidFile string
+
+// Start writes to the pidfile.
+func (pidfile PidFile) Start () error {
+	return os.WriteFile(string(pidfile), []byte(strconv.Itoa(os.Getpid())), 0644)
+}
+
+// Close deletes the pidfile.
+func (pidfile PidFile) Close () error {
+	return os.Remove(string(pidfile))
+}
+
+// Empty returns true if the object is zero value (an empty string).
+func (pidfile PidFile) Empty () bool {
+	return pidfile == ""
+}
+
+// OnSigint calls the specified function once sigint is recieved. This function
+// does not block, and spawns a goroutine that waits. For this reason, the
+// callback must be safe to call concurrently.
+func OnSigint (callback func ()) {
+	go func () {
+		sigintNotify := make(chan os.Signal, 1)
+		signal.Notify(sigintNotify, os.Interrupt, syscall.SIGTERM)
+
+		<-sigintNotify
+		callback()
+	} ()
+}
+
+// CloseOnSigint is like OnSigint, but takes an io.Closer.
+func CloseOnSigint (closer io.Closer) {
+	OnSigint(func () { closer.Close() })
+}
+
+// ShutdownOnSigint is like OnSigint, but takes an object with a Shutdown()
+// method.
+func ShutdownOnSigint (shutdowner interface { Shutdown() error }) {
+	OnSigint(func () { shutdowner.Shutdown() })
+}

routines/routines.go

@@ -6,10 +6,45 @@ import "fmt"
 import "log"
 import "time"
 import "sync"
+import "errors"
 
-// Routine is a long-running function that does not return until it is finished.
-// An error is returned if the routine exited due to an error.
-type Routine func () error
+type routine struct {
+	run, shutdown func () error
+}
+
+func (routine routine) Run () error {
+	if routine.run == nil {
+		return nil
+	} else {
+		return routine.run()
+	}
+}
+
+func (routine routine) Shutdown () error {
+	if routine.shutdown == nil {
+		return nil
+	} else {
+		return routine.shutdown()
+	}
+}
+
+// From creates a routine from a separate run and shutdown function.
+func From (run, shutdown func () error) Routine {
+	return routine {
+		run:      run,
+		shutdown: shutdown,
+	}
+} 
+
+// Routine is an object that can be run and stopped.
+type Routine interface {
+	// Run is a long-running function that does not return until it is
+	// finished. An error is returned if the routine exited due to an error.
+	Run () error
+
+	// Shutdown stops Run.
+	Shutdown () error
+}
 
 // Manager is a system capable of managing multiple routines, and restarting
 // them if they fail.
@@ -27,6 +62,9 @@ type Manager struct {
 	// is nil, messages will be written to the standard logger. To disable
 	// logging altogether, this can be set to io.Discard.
 	Logger io.Writer
+
+	stoppingMutex sync.Mutex
+	stopping bool
 }
 
 // Run spawns all routines in the Routines slice. If a routine exits with an
@@ -34,17 +72,31 @@ type Manager struct {
 // Run returns  only when all routines have exited.
 func (manager *Manager) Run () error {
 	var waitGroup sync.WaitGroup
-	var errExit   error
 	
 	for _, routine := range manager.Routines {
 		if routine != nil {
 			waitGroup.Add(1)
-			go manager.runRoutine(routine, &waitGroup, &errExit)
+			go manager.runRoutine(routine, &waitGroup)
 		}
 	}
 	
 	waitGroup.Wait()
-	return errExit
+	return nil
+}
+
+// Shutdown shuts down all routines in the manager.
+func (manager *Manager) Shutdown () (err error) {
+	manager.stoppingMutex.Lock()
+	manager.stopping = true
+	manager.stoppingMutex.Unlock()
+
+	for _, routine := range manager.Routines {
+		routineErr := routine.Shutdown()
+		if routineErr != nil {
+			err = routineErr
+		}
+	}
+	return
 }
 
 // Append adds one or more routines to the Routines slice. This has no effect if
@@ -61,15 +113,26 @@ func (manager *Manager) log (message ...any) {
 	}
 }
 
-func (manager *Manager) runRoutine (routine Routine, group *sync.WaitGroup, errExit *error) {
+func (manager *Manager) runRoutine (routine Routine, group *sync.WaitGroup) {
 	defer group.Done()
 
-	var err error
 	for {
-		// TODO: recover from panics
 		lastStart := time.Now()
-		err = routine()
+		err := panicWrap(routine.Run)
 
+		stopping := false
+		manager.stoppingMutex.Lock()
+		stopping = manager.stopping
+		manager.stoppingMutex.Unlock()
+		if stopping {
+			if err == nil {
+				manager.log("(i) stopped routine")
+			} else {
+				manager.log("!!! stopped routine, with error:", err)
+			}
+			break
+		}
+		
 		if err == nil {
 			manager.log("(i) routine exited")
 			break
@@ -84,8 +147,15 @@ func (manager *Manager) runRoutine (routine Routine, group *sync.WaitGroup, errE
 			manager.log("(i) routine is being restarted")
 		}
 	}
-	
-	if err != nil {
-		*errExit = err
-	}
+}
+
+func panicWrap (f func () error) (err error) {
+	defer func () {
+		if pan := recover(); pan != nil {
+			err = errors.New(fmt.Sprint(pan))
+		}
+	} ()
+	
+	err = f()
+	return
 }

service/http.go

@@ -19,11 +19,13 @@ type HTTP struct {
 	Handler http.Handler
 
 	conn *Conn
+	running bool
 	requests requestManager
 }
 
 // Close closes the mount abruptly, interrupting any active connections.
 func (htmount *HTTP) Close () error {
+	htmount.running = false
 	return htmount.conn.Close()
 }
 
@@ -44,12 +46,19 @@ func (htmount *HTTP) Run (service ServiceInfo) (err error) {
 	}
 	htmount.conn, err = Dial(htmount.MountInfo, service)
 	if err != nil { return }
-	
+
+	htmount.running = true	
 	htmount.requests.init()
 
 	for {
 		message, err := htmount.conn.Receive()
-		if err != nil { return err }
+		if err != nil {
+			if htmount.running {
+				return err
+			} else {
+				return nil
+			}
+		}
 		
 		switch message.(type) {
 		case protocol.MessageHTTPRequest:

service/service.go

@@ -5,6 +5,7 @@ import "os"
 import "log"
 import "time"
 import "hnakra/rotate"
+import "hnakra/daemon"
 import "hnakra/routines"
 
 // Service is capable of managing multiple mounts. It also sets up logging
@@ -12,6 +13,8 @@ import "hnakra/routines"
 type Service struct {
 	ServiceInfo
 	Mounts []Mount
+
+	manager routines.Manager
 }
 
 // NewService provides a shorthand for creating a new service, leaving most
@@ -29,6 +32,8 @@ func NewService (name, description string, mounts ...Mount) *Service {
 // Run runs the mounts within the service, and only exits when all of them have
 // exited. It will automatically start logging to the directory specified by
 // $HNAKRA_LOG_DIR. If that variable is unset, it will just log to stdout.
+// Additionally, if $HNAKRA_PIDFILE is set, it will write the process PID to the
+// file specified by it.
 func (service *Service) Run () error {
 	// set up logging
 	logDir := os.Getenv("HNAKRA_LOG_DIR")
@@ -41,16 +46,28 @@ func (service *Service) Run () error {
 	log.Println("... starting service", service.Name)
 
 	// set up routine manager
-	manager := routines.Manager { RestartDeadline: time.Second * 8 }
-	manager.Routines = make([]routines.Routine, len(service.Mounts))
+	service.manager = routines.Manager { RestartDeadline: time.Second * 8 }
+	service.manager.Routines = make([]routines.Routine, len(service.Mounts))
 	for index, mount := range service.Mounts {
-		manager.Routines[index] = func () error {
+		service.manager.Routines[index] = routines.From (func () error {
 			return mount.Run(service.ServiceInfo)
-		}
+		}, mount.Shutdown)
+	}
+
+	// be a daemon
+	daemon.ShutdownOnSigint(service)
+	pidfile := daemon.PidFile(os.Getenv("HNAKRA_PIDFILE"))
+	if !pidfile.Empty() {
+		err := pidfile.Start()
+		if err != nil { log.Println("!!! could not write pid:", err) }
+		defer func () {
+			err := pidfile.Close()
+			if err != nil { log.Println("!!! could not delete pidfile:", err) }
+		} ()
 	}
 
 	// send it
-	err := manager.Run()
+	err := service.manager.Run()
 	if err != nil { log.Println("XXX", err) }
 	return err
 }
@@ -70,11 +87,5 @@ func (service *Service) Close () (err error) {
 // Shutdown gracefully shuts down each mount in the service. This will cause
 // Run() to exit.
 func (service *Service) Shutdown () (err error) {
-	for _, mount := range service.Mounts {
-		singleErr := mount.Shutdown()
-		if singleErr != nil {
-			err = singleErr
-		}
-	}
-	return
+	return service.manager.Shutdown()
 }