New startup and shutdown directives

config/config.go

@@ -14,6 +14,51 @@ const (
 	defaultRoot = "."
 )
 
+// config represents a server configuration. It
+// is populated by parsing a config file (via the
+// Load function).
+type Config struct {
+	// The hostname or IP to which to bind the server
+	Host string
+
+	// The port to listen on
+	Port string
+
+	// The directory from which to serve files
+	Root string
+
+	// HTTPS configuration
+	TLS TLSConfig
+
+	// Middleware stack
+	Middleware map[string][]middleware.Middleware
+
+	// Functions (or methods) to execute at server start; these
+	// are executed before any parts of the server are configured,
+	// and the functions are blocking
+	Startup []func() error
+
+	// Functions (or methods) to execute when the server quits;
+	// these are executed in response to SIGINT and are blocking
+	Shutdown []func() error
+
+	// MaxCPU is the maximum number of cores for the whole process to use
+	MaxCPU int
+}
+
+// Address returns the host:port of c as a string.
+func (c Config) Address() string {
+	return c.Host + ":" + c.Port
+}
+
+// TLSConfig describes how TLS should be configured and used,
+// if at all. A certificate and key are both required.
+type TLSConfig struct {
+	Enabled     bool
+	Certificate string
+	Key         string
+}
+
 // Load loads a configuration file, parses it,
 // and returns a slice of Config structs which
 // can be used to create and configure server
@@ -54,43 +99,3 @@ func Default() []Config {
 	}
 	return cfg
 }
-
-// config represents a server configuration. It
-// is populated by parsing a config file (via the
-// Load function).
-type Config struct {
-	// The hostname or IP to which to bind the server
-	Host string
-
-	// The port to listen on
-	Port string
-
-	// The directory from which to serve files
-	Root string
-
-	// HTTPS configuration
-	TLS TLSConfig
-
-	// Middleware stack
-	Middleware map[string][]middleware.Middleware
-
-	// Functions (or methods) to execute at server start; these
-	// are executed before any parts of the server are configured
-	Startup []func() error
-
-	// MaxCPU is the maximum number of cores for the whole process to use
-	MaxCPU int
-}
-
-// Address returns the host:port of c as a string.
-func (c Config) Address() string {
-	return c.Host + ":" + c.Port
-}
-
-// TLSConfig describes how TLS should be configured and used,
-// if at all. At least a certificate and key are required.
-type TLSConfig struct {
-	Enabled     bool
-	Certificate string
-	Key         string
-}

config/directives.go

@@ -2,9 +2,12 @@ package config
 
 import (
 	"os"
+	"os/exec"
 	"runtime"
 	"strconv"
 	"strings"
+
+	"github.com/mholt/caddy/middleware"
 )
 
 // dirFunc is a type of parsing function which processes
@@ -111,5 +114,55 @@ func init() {
 			}
 			return nil
 		},
+		"startup": func(p *parser) error {
+			// TODO: This code is duplicated with the shutdown directive below
+
+			if !p.nextArg() {
+				return p.argErr()
+			}
+
+			command, args, err := middleware.SplitCommandAndArgs(p.tkn())
+			if err != nil {
+				return p.err("Parse", err.Error())
+			}
+
+			startupfn := func() error {
+				cmd := exec.Command(command, args...)
+				cmd.Stdout = os.Stdout
+				cmd.Stderr = os.Stderr
+				err := cmd.Run()
+				if err != nil {
+					return err
+				}
+				return nil
+			}
+
+			p.cfg.Startup = append(p.cfg.Startup, startupfn)
+			return nil
+		},
+		"shutdown": func(p *parser) error {
+			if !p.nextArg() {
+				return p.argErr()
+			}
+
+			command, args, err := middleware.SplitCommandAndArgs(p.tkn())
+			if err != nil {
+				return p.err("Parse", err.Error())
+			}
+
+			shutdownfn := func() error {
+				cmd := exec.Command(command, args...)
+				cmd.Stdout = os.Stdout
+				cmd.Stderr = os.Stderr
+				err := cmd.Run()
+				if err != nil {
+					return err
+				}
+				return nil
+			}
+
+			p.cfg.Shutdown = append(p.cfg.Shutdown, shutdownfn)
+			return nil
+		},
 	}
 }

middleware/commands.go

+package middleware
+
+import (
+	"errors"
+
+	"github.com/flynn/go-shlex"
+)
+
+// SplitCommandAndArgs takes a command string and parses it
+// shell-style into the command and its separate arguments.
+func SplitCommandAndArgs(command string) (cmd string, args []string, err error) {
+	parts, err := shlex.Split(command)
+	if err != nil {
+		err = errors.New("Error parsing command: " + err.Error())
+		return
+	} else if len(parts) == 0 {
+		err = errors.New("No command contained in '" + command + "'")
+		return
+	}
+
+	cmd = parts[0]
+	if len(parts) > 1 {
+		args = parts[1:]
+	}
+
+	return
+}

middleware/websockets/websockets.go

@@ -4,10 +4,8 @@
 package websockets
 
 import (
-	"errors"
 	"net/http"
 
-	"github.com/flynn/go-shlex"
 	"github.com/mholt/caddy/middleware"
 	"golang.org/x/net/websocket"
 )
@@ -101,7 +99,7 @@ func New(c middleware.Controller) (middleware.Middleware, error) {
 		}
 
 		// Split command into the actual command and its arguments
-		cmd, args, err := parseCommandAndArgs(command)
+		cmd, args, err := middleware.SplitCommandAndArgs(command)
 		if err != nil {
 			return nil, err
 		}
@@ -122,26 +120,6 @@ func New(c middleware.Controller) (middleware.Middleware, error) {
 	}, nil
 }
 
-// parseCommandAndArgs takes a command string and parses it
-// shell-style into the command and its separate arguments.
-func parseCommandAndArgs(command string) (cmd string, args []string, err error) {
-	parts, err := shlex.Split(command)
-	if err != nil {
-		err = errors.New("Error parsing command for websocket: " + err.Error())
-		return
-	} else if len(parts) == 0 {
-		err = errors.New("No command found for use by websocket")
-		return
-	}
-
-	cmd = parts[0]
-	if len(parts) > 1 {
-		args = parts[1:]
-	}
-
-	return
-}
-
 var (
 	// See CGI spec, 4.1.4
 	GatewayInterface string

server/server.go

@@ -7,6 +7,8 @@ import (
 	"errors"
 	"log"
 	"net/http"
+	"os"
+	"os/signal"
 	"runtime"
 
 	"github.com/bradfitz/http2"
@@ -75,6 +77,21 @@ func (s *Server) Serve() error {
 
 	http2.ConfigureServer(server, nil) // TODO: This may not be necessary after HTTP/2 merged into std lib
 
+	// Execute shutdown commands on exit
+	// TODO: Is graceful net/http shutdown necessary?
+	go func() {
+		interrupt := make(chan os.Signal, 1)
+		signal.Notify(interrupt, os.Interrupt, os.Kill) // TODO: syscall.SIGQUIT? (Ctrl+\, Unix-only)
+		<-interrupt
+		for _, shutdownFunc := range s.config.Shutdown {
+			err := shutdownFunc()
+			if err != nil {
+				log.Fatal(err)
+			}
+		}
+		os.Exit(0)
+	}()
+
 	if s.config.TLS.Enabled {
 		return server.ListenAndServeTLS(s.config.TLS.Certificate, s.config.TLS.Key)
 	} else {
@@ -103,6 +120,7 @@ func (s *Server) Log(v ...interface{}) {
 func (s *Server) buildStack() error {
 	s.fileServer = FileServer(http.Dir(s.config.Root))
 
+	// Execute startup functions
 	for _, start := range s.config.Startup {
 		err := start()
 		if err != nil {