command-run.go

/*
  Copyright (c) 2012-2013 José Carlos Nieto, http://xiam.menteslibres.org/

  Permission is hereby granted, free of charge, to any person obtaining
  a copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so, subject to
  the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

package main

import (
	"errors"
	"flag"
	"fmt"
	//"github.com/howeyc/fsnotify"
	"log"
	"menteslibres.net/gosexy/cli"
	"menteslibres.net/gosexy/to"
	"menteslibres.net/gosexy/yaml"
	"menteslibres.net/luminos/host"
	"menteslibres.net/luminos/watcher"
	"net"
	"net/http"
	"net/http/fcgi"
	"os"
	"strings"
)

// Default values
const DEFAULT_SETTINGS_FILE = "./settings.yaml"
const DEFAULT_SERVER_DOMAIN = "unix"
const DEFAULT_SERVER_PROTOCOL = "tcp"

// Global settings.
var settings *yaml.Yaml

// Host map.
var hosts map[string]*host.Host

// Settings
var flagSettings = flag.String("c", DEFAULT_SETTINGS_FILE, "Path to the settings.yaml file.")

var watch *watcher.Watcher

func init() {

	cli.Register("run", cli.Entry{
		Name:        "run",
		Description: "Runs a luminos server.",
		Arguments:   []string{"c"},
		Command:     &runCommand{},
	})

	hosts = make(map[string]*host.Host)
}

type server struct {
}

type runCommand struct {
}

// Dispatches a request and returns the appropriate host.
func route(req *http.Request) *host.Host {

	name := req.Host

	// Stripping port from request.
	if strings.Contains(name, ":") {
		name = name[0:strings.Index(name, ":")]
	}

	path := name + req.URL.Path

	// Searching for best match for host.
	match := ""

	for key, _ := range hosts {
		lkey := len(key)
		if lkey >= len(match) && lkey <= len(path) {
			if path[0:lkey] == key {
				match = key
			}
		}
	}

	if match == "" {
		log.Printf("Could not match any host: %s, falling back to default.\n", req.Host)
		match = "default"
	}

	if _, ok := hosts[match]; ok == true {
		return hosts[match]
	}

	log.Printf("Request for unknown host: %s\n", req.Host)

	return nil

}

// Routes a request and lets the host handle it.
func (self server) ServeHTTP(wri http.ResponseWriter, req *http.Request) {
	r := route(req)
	if r != nil {
		r.ServeHTTP(wri, req)
	} else {
		log.Printf("Failed to serve host %s.\n", req.Host)
	}
}

// Loads settings
func loadSettings(file string) (*yaml.Yaml, error) {

	var entries map[interface{}]interface{}
	var ok bool

	// Trying to read settings from file.
	y, err := yaml.Open(file)

	if err != nil {
		return nil, err
	}

	// Loading and verifying host entries
	if entries, ok = y.Get("hosts").(map[interface{}]interface{}); ok == false {
		return nil, errors.New("Missing \"hosts\" entry.")
	}

	h := map[string]*host.Host{}

	for key, _ := range entries {
		name := to.String(key)
		path := to.String(entries[name])

		info, err := os.Stat(path)
		if err != nil {
			return nil, fmt.Errorf("Failed to validate host %s: %s.", name, err.Error())
		}
		if info.IsDir() == false {
			return nil, fmt.Errorf("Host %s does not point to a directory.", name)
		}

		h[name], err = host.New(name, path)

		if err != nil {
			return nil, fmt.Errorf("Failed to initialize host %s: %s.", name, err.Error())
		}
	}

	for name, _ := range hosts {
		hosts[name].Close()
	}

	hosts = h

	if _, ok := hosts["default"]; ok == false {
		log.Printf("Warning: default host was not provided.")
	}

	return y, nil
}

func settingsWatcher() error {

	var err error

	/*
		// Watching settings file for changes.
		// Was not properly returning events on OSX.
		// https://github.com/howeyc/fsnotify/issues/34

		watcher, err := fsnotify.NewWatcher()

		if err == nil {
			defer watcher.Close()

			go func() {
				for {
					select {
					case ev := <-watcher.Event:
						if ev == nil {
							return
						}
						if ev.IsModify() {
							log.Printf("Trying to reload settings file %s...\n", ev.Name)
							y, err := loadSettings(ev.Name)
							if err != nil {
								log.Printf("Error loading settings file %s: %s\n", ev.Name, err.Error())
							} else {
								settings = y
							}
						} else if ev.IsDelete() {
							watcher.RemoveWatch(ev.Name)
							watcher.Watch(ev.Name)
						}
					case err := <-watcher.Error:
						log.Printf("Watcher error: %s\n", err.Error())
					}
				}
			}()

			watcher.Watch(settingsFile)
		}
	*/

	// (Stupid) file modification watcher.
	watch, err = watcher.New()

	if err == nil {
		go func() {
			defer watch.Close()
			for {
				select {
				case ev := <-watch.Event:
					if ev.IsModify() {
						y, err := loadSettings(ev.Name)
						if err != nil {
							log.Printf("Error loading settings file %s: %s\n", ev.Name, err.Error())
						} else {
							log.Printf("Reloading settings file %s.\n", ev.Name)
							settings = y
						}
					}
				}
			}
		}()

	}

	return err
}

func (self *runCommand) Execute() error {

	// Default settings file.
	if *flagSettings == "" {
		*flagSettings = DEFAULT_SETTINGS_FILE
	}

	stat, err := os.Stat(*flagSettings)

	if err != nil {
		return fmt.Errorf("Error while opening %s: %s", *flagSettings, err.Error())
	}

	if stat != nil {

		if stat.IsDir() == true {

			return fmt.Errorf("Could not open %s: it's a directory!", *flagSettings)

		} else {

			settings, err = loadSettings(*flagSettings)

			if err != nil {
				return fmt.Errorf("Error while reading settings file %s: %s", *flagSettings, err.Error())
			}

			err = settingsWatcher()

			if err == nil {
				watch.Watch(*flagSettings)
			}

			serverType := to.String(settings.Get("server", "type"))

			domain := DEFAULT_SERVER_DOMAIN
			address := to.String(settings.Get("server", "socket"))

			if address == "" {
				domain = DEFAULT_SERVER_PROTOCOL
				address = fmt.Sprintf("%s:%d", to.String(settings.Get("server", "bind")), to.Int64(settings.Get("server", "port")))
			}

			listener, err := net.Listen(domain, address)

			if err != nil {
				return err
			}

			defer listener.Close()

			switch serverType {
			case "fastcgi":
				if err == nil {
					log.Printf("Starting FastCGI server. Listening at %s.", address)
					fcgi.Serve(listener, &server{})
				} else {
					return fmt.Errorf("Failed to start FastCGI server: %s", err.Error())
				}
			case "standalone":
				if err == nil {
					log.Printf("Starting HTTP server. Listening at %s.", address)
					http.Serve(listener, &server{})
				} else {
					return fmt.Errorf("Failed to start HTTP server: %s", err.Error())
				}
			default:
				return fmt.Errorf("Unknown server type: %s", serverType)
			}

		}
	} else {
		return fmt.Errorf("Could not load settings file: %s.", *flagSettings)
	}

	return nil
}