Started work on multi file hooks loading

hook/hook.go

@@ -273,7 +273,7 @@ func (h *ResponseHeaders) String() string {
 		result[idx] = fmt.Sprintf("%s=%s", responseHeader.Name, responseHeader.Value)
 	}
 
-	return fmt.Sprint(strings.Join(result, ", "))
+	return strings.Join(result, ", ")
 }
 
 // Set method appends new Header object from header=value notation
@@ -288,6 +288,23 @@ func (h *ResponseHeaders) Set(value string) error {
 	return nil
 }
 
+// HooksFiles is a slice of String
+type HooksFiles []string
+
+func (h *HooksFiles) String() string {
+	if len(*h) == 0 {
+		return "hooks.json"
+	}
+
+	return strings.Join(*h, ", ")
+}
+
+// Set method appends new string
+func (h *HooksFiles) Set(value string) error {
+	*h = append(*h, value)
+	return nil
+}
+
 // Hook type is a structure containing details for a single hook
 type Hook struct {
 	ID                       string          `json:"id,omitempty"`
@@ -426,6 +443,19 @@ func (h *Hooks) LoadFromFile(path string) error {
 	return e
 }
 
+// Append appends hooks unless the new hooks contain a hook with an ID that already exists
+func (h *Hooks) Append(other *Hooks) error {
+	for _, hook := range *other {
+		if h.Match(hook.ID) != nil {
+			return fmt.Errorf("hook with ID %s is already defined", hook.ID)
+		}
+
+		*h = append(*h, hook)
+	}
+
+	return nil
+}
+
 // Match iterates through Hooks and returns first one that matches the given ID,
 // if no hook matches the given ID, nil is returned
 func (h *Hooks) Match(id string) *Hook {

signals.go

@@ -26,7 +26,7 @@ func watchForSignals() {
 		if sig == syscall.SIGUSR1 {
 			log.Println("caught USR1 signal")
 
-			reloadHooks()
+			reloadAllHooks()
 		} else {
 			log.Printf("caught unhandled signal %+v\n", sig)
 		}

webhook.go

@@ -21,7 +21,7 @@ import (
 )
 
 const (
-	version = "2.6.0"
+	version = "2.6.1"
 )
 
 var (
@@ -30,7 +30,6 @@ var (
 	verbose            = flag.Bool("verbose", false, "show verbose output")
 	noPanic            = flag.Bool("nopanic", false, "do not panic if hooks cannot be loaded when webhook is not running in verbose mode")
 	hotReload          = flag.Bool("hotreload", false, "watch hooks file for changes and reload them automatically")
-	hooksFilePath      = flag.String("hooks", "hooks.json", "path to the json file containing defined hooks the webhook should serve")
 	hooksURLPrefix     = flag.String("urlprefix", "hooks", "url prefix to use for served hooks (protocol://yourserver:port/PREFIX/:hook-id)")
 	secure             = flag.Bool("secure", false, "use HTTPS instead of HTTP")
 	cert               = flag.String("cert", "cert.pem", "path to the HTTPS certificate pem file")
@@ -38,20 +37,43 @@ var (
 	justDisplayVersion = flag.Bool("version", false, "display webhook version and quit")
 
 	responseHeaders hook.ResponseHeaders
+	hooksFiles      hook.HooksFiles
+
+	loadedHooksFromFiles = make(map[string]hook.Hooks)
 
 	watcher *fsnotify.Watcher
 	signals chan os.Signal
-
-	hooks hook.Hooks
 )
 
-func main() {
-	hooks = hook.Hooks{}
+func matchLoadedHook(id string) *hook.Hook {
+	for _, hooks := range loadedHooksFromFiles {
+		if hook := hooks.Match(id); hook != nil {
+			return hook
+		}
+	}
 
+	return nil
+}
+
+func lenLoadedHooks() int {
+	sum := 0
+	for _, hooks := range loadedHooksFromFiles {
+		sum += len(hooks)
+	}
+
+	return sum
+}
+
+func main() {
+	flag.Var(&hooksFiles, "hooks", "path to the json file containing defined hooks the webhook should serve, use multiple times to load from different files")
 	flag.Var(&responseHeaders, "header", "response header to return, specified in format name=value, use multiple times to set multiple headers")
 
 	flag.Parse()
 
+	if len(hooksFiles) == 0 {
+		log.Fatalln("you must specify at least one file to load hooks from")
+	}
+
 	if *justDisplayVersion {
 		fmt.Println("webhook version " + version)
 		os.Exit(0)
@@ -70,50 +92,54 @@ func main() {
 	setupSignals()
 
 	// load and parse hooks
-	log.Printf("attempting to load hooks from %s\n", *hooksFilePath)
+	for _, hooksFilePath := range hooksFiles {
+		log.Printf("attempting to load hooks from %s\n", hooksFilePath)
 
-	err := hooks.LoadFromFile(*hooksFilePath)
+		newHooks := hook.Hooks{}
 
-	if err != nil {
-		if !*verbose && !*noPanic {
-			log.SetOutput(os.Stdout)
-			log.Fatalf("couldn't load any hooks from file! %+v\naborting webhook execution since the -verbose flag is set to false.\nIf, for some reason, you want webhook to start without the hooks, either use -verbose flag, or -nopanic", err)
-		}
+		err := newHooks.LoadFromFile(hooksFilePath)
 
-		log.Printf("couldn't load hooks from file! %+v\n", err)
-	} else {
-		seenHooksIds := make(map[string]bool)
+		if err != nil {
+			log.Printf("couldn't load hooks from file! %+v\n", err)
+		} else {
+			log.Printf("found %d hook(s) in file\n", len(newHooks))
 
-		log.Printf("found %d hook(s) in file\n", len(hooks))
-
-		for _, hook := range hooks {
-			if seenHooksIds[hook.ID] == true {
-				log.Fatalf("error: hook with the id %s has already been loaded!\nplease check your hooks file for duplicate hooks ids!\n", hook.ID)
+			for _, hook := range newHooks {
+				if matchLoadedHook(hook.ID) != nil {
+					log.Fatalf("error: hook with the id %s has already been loaded!\nplease check your hooks file for duplicate hooks ids!\n", hook.ID)
+				}
+				log.Printf("\tloaded: %s\n", hook.ID)
 			}
-			seenHooksIds[hook.ID] = true
-			log.Printf("\tloaded: %s\n", hook.ID)
+
+			loadedHooksFromFiles[hooksFilePath] = newHooks
 		}
 	}
 
-	if *hotReload {
-		// set up file watcher
-		log.Printf("setting up file watcher for %s\n", *hooksFilePath)
+	if !*verbose && !*noPanic && lenLoadedHooks() == 0 {
+		log.SetOutput(os.Stdout)
+		log.Fatalln("couldn't load any hooks from file!\naborting webhook execution since the -verbose flag is set to false.\nIf, for some reason, you want webhook to start without the hooks, either use -verbose flag, or -nopanic")
+	}
 
+	if *hotReload {
 		var err error
 
 		watcher, err = fsnotify.NewWatcher()
 		if err != nil {
 			log.Fatal("error creating file watcher instance", err)
 		}
-
 		defer watcher.Close()
 
-		go watchForFileChange()
+		for _, hooksFilePath := range hooksFiles {
+			// set up file watcher
+			log.Printf("setting up file watcher for %s\n", hooksFilePath)
 
-		err = watcher.Add(*hooksFilePath)
-		if err != nil {
-			log.Fatal("error adding hooks file to the watcher", err)
+			err = watcher.Add(hooksFilePath)
+			if err != nil {
+				log.Fatal("error adding hooks file to the watcher", err)
+			}
 		}
+
+		go watchForFileChange()
 	}
 
 	l := negroni.NewLogger()
@@ -159,7 +185,7 @@ func hookHandler(w http.ResponseWriter, r *http.Request) {
 
 	id := mux.Vars(r)["id"]
 
-	if matchedHook := hooks.Match(id); matchedHook != nil {
+	if matchedHook := matchLoadedHook(id); matchedHook != nil {
 		log.Printf("%s got matched\n", id)
 
 		body, err := ioutil.ReadAll(r.Body)
@@ -291,32 +317,48 @@ func handleHook(h *hook.Hook, headers, query, payload *map[string]interface{}, b
 	return string(out), err
 }
 
-func reloadHooks() {
-	newHooks := hook.Hooks{}
+func reloadHooks(hooksFilePath string) {
+	hooksInFile := hook.Hooks{}
 
 	// parse and swap
-	log.Printf("attempting to reload hooks from %s\n", *hooksFilePath)
+	log.Printf("attempting to reload hooks from %s\n", hooksFilePath)
 
-	err := newHooks.LoadFromFile(*hooksFilePath)
+	err := hooksInFile.LoadFromFile(hooksFilePath)
 
 	if err != nil {
 		log.Printf("couldn't load hooks from file! %+v\n", err)
 	} else {
 		seenHooksIds := make(map[string]bool)
 
-		log.Printf("found %d hook(s) in file\n", len(newHooks))
+		log.Printf("found %d hook(s) in file\n", len(hooksInFile))
 
-		for _, hook := range newHooks {
-			if seenHooksIds[hook.ID] == true {
+		for _, hook := range hooksInFile {
+			wasHookIDAlreadyLoaded := false
+
+			for _, loadedHook := range loadedHooksFromFiles[hooksFilePath] {
+				if loadedHook.ID == hook.ID {
+					wasHookIDAlreadyLoaded = true
+					break
+				}
+			}
+
+			if (matchLoadedHook(hook.ID) != nil && !wasHookIDAlreadyLoaded) || seenHooksIds[hook.ID] == true {
 				log.Printf("error: hook with the id %s has already been loaded!\nplease check your hooks file for duplicate hooks ids!", hook.ID)
 				log.Println("reverting hooks back to the previous configuration")
 				return
 			}
+
 			seenHooksIds[hook.ID] = true
 			log.Printf("\tloaded: %s\n", hook.ID)
 		}
 
-		hooks = newHooks
+		loadedHooksFromFiles[hooksFilePath] = hooksInFile
+	}
+}
+
+func reloadAllHooks() {
+	for _, hooksFilePath := range hooksFiles {
+		reloadHooks(hooksFilePath)
 	}
 }
 
@@ -325,9 +367,8 @@ func watchForFileChange() {
 		select {
 		case event := <-(*watcher).Events:
 			if event.Op&fsnotify.Write == fsnotify.Write {
-				log.Println("hooks file modified")
-
-				reloadHooks()
+				log.Printf("hooks file %s modified\n", event.Name)
+				reloadHooks(event.Name)
 			}
 		case err := <-(*watcher).Errors:
 			log.Println("watcher error:", err)