feat: Create worker queue.

Makefile

@@ -1,5 +1,5 @@
 .SILENT :
-.PHONY : volume build clean run shell test
+.PHONY : volume dev build clean run shell test dist
 
 USERNAME:=ncarlier
 APPNAME:=webhookd
@@ -18,16 +18,16 @@ define docker_run_flags
 -i -t
 endef
 
-ifdef DEVMODE
-	docker_run_flags += --volumes-from $(APPNAME)_volumes
-endif
-
 all: build
 
 volume:
 	echo "Building $(APPNAME) volumes..."
 	sudo docker run -v $(PWD):/opt/$(APPNAME) -v ~/var/$(APPNAME):/var/opt/$(APPNAME) --name $(APPNAME)_volumes busybox true
 
+dev:
+	$(eval docker_run_flags += --volumes-from $(APPNAME)_volumes)
+	echo "DEVMODE: Using volumes from $(APPNAME)_volumes"
+
 build:
 	echo "Building $(IMAGE) docker image..."
 	sudo docker build --rm -t $(IMAGE) .

src/notification/http_notifier.go

@@ -102,7 +102,7 @@ func (n *HttpNotifier) Notify(subject string, text string, attachfile string) {
 
 		// Check the response
 		if res.StatusCode != http.StatusOK {
-			log.Println("bad status: %s", res.Status)
+			log.Println("bad status: ", res.Status)
 			log.Println(res.Body)
 			return
 		}

src/tools/compress.go

@@ -16,7 +16,7 @@ func CompressFile(filename string) (zipfile string, err error) {
 	}
 	out, err := os.Create(zipfile)
 	if err != nil {
-		log.Println("Unable to create zip file", err)
+		log.Println("Unable to create gzip file", err)
 		return
 	}
 
@@ -29,9 +29,9 @@ func CompressFile(filename string) (zipfile string, err error) {
 
 	_, err = bufin.WriteTo(gw)
 	if err != nil {
-		log.Println("Unable to write into the zip file", err)
+		log.Println("Unable to write into the gzip file", err)
 		return
 	}
-	log.Println("Zip file created: ", zipfile)
+	log.Println("Gzip file created: ", zipfile)
 	return
 }

src/webhookd.go

@@ -5,105 +5,32 @@ import (
 	"fmt"
 	"github.com/gorilla/mux"
 	"github.com/ncarlier/webhookd/hook"
-	"github.com/ncarlier/webhookd/notification"
-	"github.com/ncarlier/webhookd/tools"
+	"github.com/ncarlier/webhookd/worker"
 	"log"
 	"net/http"
-	"os"
-	"os/exec"
-	"path"
 )
 
 var (
-	laddr      = flag.String("l", ":8080", "HTTP service address (e.g.address, ':8080')")
-	workingdir = os.Getenv("APP_WORKING_DIR")
-	scriptsdir = os.Getenv("APP_SCRIPTS_DIR")
+	LAddr    = flag.String("l", ":8080", "HTTP service address (e.g.address, ':8080')")
+	NWorkers = flag.Int("n", 2, "The number of workers to start")
 )
 
-type HookContext struct {
-	Hook   string
-	Action string
-	args   []string
-}
-
-func Notify(subject string, text string, outfilename string) {
-	var notifier, err = notification.NotifierFactory()
-	if err != nil {
-		log.Println(err)
-		return
-	}
-	if notifier == nil {
-		log.Println("Notification provider not found.")
-		return
-	}
-
-	var zipfile string
-	if outfilename != "" {
-		zipfile, err = tools.CompressFile(outfilename)
-		if err != nil {
-			log.Println(err)
-			zipfile = outfilename
-		}
-	}
-
-	notifier.Notify(subject, text, zipfile)
-}
-
-func RunScript(w http.ResponseWriter, context *HookContext) {
-	scriptname := path.Join(scriptsdir, context.Hook, fmt.Sprintf("%s.sh", context.Action))
-	log.Println("Exec script: ", scriptname)
-
-	cmd := exec.Command(scriptname, context.args...)
-	var ErrorHandler func(err error, out string)
-	ErrorHandler = func(err error, out string) {
-		subject := fmt.Sprintf("Webhook %s/%s FAILED.", context.Hook, context.Action)
-		Notify(subject, err.Error(), out)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-	}
-
-	// open the out file for writing
-	outfilename := path.Join(workingdir, fmt.Sprintf("%s-%s.txt", context.Hook, context.Action))
-	outfile, err := os.Create(outfilename)
-	if err != nil {
-		ErrorHandler(err, "")
-		return
-	}
-
-	defer outfile.Close()
-	cmd.Stdout = outfile
-
-	err = cmd.Start()
-	if err != nil {
-		ErrorHandler(err, "")
-		return
-	}
-
-	err = cmd.Wait()
-	if err != nil {
-		ErrorHandler(err, outfilename)
-		return
-	}
-
-	subject := fmt.Sprintf("Webhook %s/%s SUCCEEDED.", context.Hook, context.Action)
-	Notify(subject, "See attached file for logs.", outfilename)
-	fmt.Fprintf(w, subject)
-}
-
 func Handler(w http.ResponseWriter, r *http.Request) {
 	params := mux.Vars(r)
-	context := new(HookContext)
-	context.Hook = params["hookname"]
-	context.Action = params["action"]
+	hookname := params["hookname"]
+	action := params["action"]
 
-	var record, err = hook.RecordFactory(context.Hook)
+	// Get hook decoder
+	record, err := hook.RecordFactory(hookname)
 	if err != nil {
 		log.Println(err.Error())
 		http.Error(w, err.Error(), http.StatusNotFound)
 		return
 	}
 
-	log.Println("Using hook: ", context.Hook)
+	fmt.Printf("Using hook %s with action %s.\n", hookname, action)
 
+	// Decode request
 	err = record.Decode(r)
 	if err != nil {
 		log.Println(err.Error())
@@ -111,27 +38,32 @@ func Handler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	log.Println("Extracted data: ", record.GetURL(), record.GetName())
-	context.args = []string{record.GetURL(), record.GetName()}
+	// Create work
+	work := new(worker.WorkRequest)
+	work.Name = hookname
+	work.Action = action
+	fmt.Println("Extracted data: ", record.GetURL(), record.GetName())
+	work.Args = []string{record.GetURL(), record.GetName()}
 
-	RunScript(w, context)
+	//Put work in queue
+	worker.WorkQueue <- *work
+	fmt.Printf("Work request queued: %s/%s\n", hookname, action)
+
+	fmt.Fprintf(w, "Action %s of hook %s queued.", action, hookname)
 }
 
 func main() {
-	if workingdir == "" {
-		workingdir = os.TempDir()
-	}
-	if scriptsdir == "" {
-		scriptsdir = "scripts"
-	}
-
 	flag.Parse()
 
+	// Start the dispatcher.
+	fmt.Println("Starting the dispatcher")
+	worker.StartDispatcher(*NWorkers)
+
 	rtr := mux.NewRouter()
 	rtr.HandleFunc("/{hookname:[a-z]+}/{action:[a-z]+}", Handler).Methods("POST")
 
 	http.Handle("/", rtr)
 
-	log.Println("webhookd server listening...")
-	log.Fatal(http.ListenAndServe(*laddr, nil))
+	fmt.Println("webhookd server listening...")
+	log.Fatal(http.ListenAndServe(*LAddr, nil))
 }

src/worker/dispatcher.go

@@ -0,0 +1,35 @@
+package worker
+
+import (
+	"fmt"
+)
+
+var WorkerQueue chan chan WorkRequest
+var WorkQueue = make(chan WorkRequest, 100)
+
+func StartDispatcher(nworkers int) {
+	// First, initialize the channel we are going to but the workers' work channels into.
+	WorkerQueue = make(chan chan WorkRequest, nworkers)
+
+	// Now, create all of our workers.
+	for i := 0; i < nworkers; i++ {
+		fmt.Println("Starting worker", i+1)
+		worker := NewWorker(i+1, WorkerQueue)
+		worker.Start()
+	}
+
+	go func() {
+		for {
+			select {
+			case work := <-WorkQueue:
+				fmt.Println("Received work requeust")
+				go func() {
+					worker := <-WorkerQueue
+
+					fmt.Println("Dispatching work request")
+					worker <- work
+				}()
+			}
+		}
+	}()
+}

src/worker/script_runner.go

@@ -0,0 +1,50 @@
+package worker
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path"
+)
+
+var (
+	workingdir = os.Getenv("APP_WORKING_DIR")
+	scriptsdir = os.Getenv("APP_SCRIPTS_DIR")
+)
+
+func RunScript(work *WorkRequest) (string, error) {
+	if workingdir == "" {
+		workingdir = os.TempDir()
+	}
+	if scriptsdir == "" {
+		scriptsdir = "scripts"
+	}
+
+	scriptname := path.Join(scriptsdir, work.Name, fmt.Sprintf("%s.sh", work.Action))
+	fmt.Println("Exec script: ", scriptname)
+
+	// Exec script...
+	cmd := exec.Command(scriptname, work.Args...)
+
+	// Open the out file for writing
+	outfilename := path.Join(workingdir, fmt.Sprintf("%s-%s.txt", work.Name, work.Action))
+	outfile, err := os.Create(outfilename)
+	if err != nil {
+		return "", err
+	}
+
+	defer outfile.Close()
+	cmd.Stdout = outfile
+
+	err = cmd.Start()
+	if err != nil {
+		return "", err
+	}
+
+	err = cmd.Wait()
+	if err != nil {
+		return "", err
+	}
+
+	return outfilename, nil
+}

src/worker/work_request.go

@@ -0,0 +1,7 @@
+package worker
+
+type WorkRequest struct {
+	Name   string
+	Action string
+	Args   []string
+}

src/worker/worker.go

@@ -0,0 +1,89 @@
+package worker
+
+import (
+	"fmt"
+	"github.com/ncarlier/webhookd/notification"
+	"github.com/ncarlier/webhookd/tools"
+)
+
+// NewWorker creates, and returns a new Worker object. Its only argument
+// is a channel that the worker can add itself to whenever it is done its
+// work.
+func NewWorker(id int, workerQueue chan chan WorkRequest) Worker {
+	// Create, and return the worker.
+	worker := Worker{
+		ID:          id,
+		Work:        make(chan WorkRequest),
+		WorkerQueue: workerQueue,
+		QuitChan:    make(chan bool)}
+
+	return worker
+}
+
+type Worker struct {
+	ID          int
+	Work        chan WorkRequest
+	WorkerQueue chan chan WorkRequest
+	QuitChan    chan bool
+}
+
+// This function "starts" the worker by starting a goroutine, that is
+// an infinite "for-select" loop.
+func (w Worker) Start() {
+	go func() {
+		for {
+			// Add ourselves into the worker queue.
+			w.WorkerQueue <- w.Work
+
+			select {
+			case work := <-w.Work:
+				// Receive a work request.
+				fmt.Printf("worker%d: Received work request %s/%s\n", w.ID, work.Name, work.Action)
+				filename, err := RunScript(&work)
+				if err != nil {
+					subject := fmt.Sprintf("Webhook %s/%s FAILED.", work.Name, work.Action)
+					Notify(subject, err.Error(), "")
+				} else {
+					subject := fmt.Sprintf("Webhook %s/%s SUCCEEDED.", work.Name, work.Action)
+					Notify(subject, "See attachment.", filename)
+				}
+			case <-w.QuitChan:
+				// We have been asked to stop.
+				fmt.Printf("worker%d stopping\n", w.ID)
+				return
+			}
+		}
+	}()
+}
+
+// Stop tells the worker to stop listening for work requests.
+//
+// Note that the worker will only stop *after* it has finished its work.
+func (w Worker) Stop() {
+	go func() {
+		w.QuitChan <- true
+	}()
+}
+
+func Notify(subject string, text string, outfilename string) {
+	var notifier, err = notification.NotifierFactory()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	if notifier == nil {
+		fmt.Println("Notification provideri not found.")
+		return
+	}
+
+	var zipfile string
+	if outfilename != "" {
+		zipfile, err = tools.CompressFile(outfilename)
+		if err != nil {
+			fmt.Println(err)
+			zipfile = outfilename
+		}
+	}
+
+	notifier.Notify(subject, text, zipfile)
+}