Move packages to proejct/pkg to follow go project folder structure convention (#1190)

cmd/fetcher/app/server.go

@@ -0,0 +1,122 @@
+package app
+
+import (
+	"context"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"net/http"
+	"os"
+
+	"go.opencensus.io/exporter/jaeger"
+	"go.opencensus.io/plugin/ochttp"
+	"go.opencensus.io/trace"
+	"go.uber.org/zap"
+
+	"github.com/fission/fission/pkg/fetcher"
+	"github.com/fission/fission/pkg/types"
+)
+
+func registerTraceExporter(collectorEndpoint string) error {
+	if collectorEndpoint == "" {
+		return nil
+	}
+
+	serviceName := "Fission-Fetcher"
+	exporter, err := jaeger.NewExporter(jaeger.Options{
+		CollectorEndpoint: collectorEndpoint,
+		Process: jaeger.Process{
+			ServiceName: serviceName,
+			Tags: []jaeger.Tag{
+				jaeger.BoolTag("fission", true),
+			},
+		},
+	})
+	if err != nil {
+		return err
+	}
+	trace.RegisterExporter(exporter)
+	trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
+	return nil
+}
+
+func Run(logger *zap.Logger) {
+	flag.Usage = fetcherUsage
+	collectorEndpoint := flag.String("jaeger-collector-endpoint", "", "")
+	specializeOnStart := flag.Bool("specialize-on-startup", false, "Flag to activate specialize process at pod starup")
+	specializePayload := flag.String("specialize-request", "", "JSON payload for specialize request")
+	secretDir := flag.String("secret-dir", "", "Path to shared secrets directory")
+	configDir := flag.String("cfgmap-dir", "", "Path to shared configmap directory")
+
+	flag.Parse()
+	if flag.NArg() == 0 {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	dir := flag.Arg(0)
+	if _, err := os.Stat(dir); err != nil {
+		if os.IsNotExist(err) {
+			err = os.MkdirAll(dir, os.ModeDir|0700)
+			if err != nil {
+				logger.Fatal("error creating directory", zap.Error(err), zap.String("directory", dir))
+			}
+		}
+	}
+
+	if err := registerTraceExporter(*collectorEndpoint); err != nil {
+		logger.Fatal("could not register trace exporter", zap.Error(err), zap.String("collector_endpoint", *collectorEndpoint))
+	}
+
+	f, err := fetcher.MakeFetcher(logger, dir, *secretDir, *configDir)
+	if err != nil {
+		logger.Fatal("error making fetcher", zap.Error(err))
+	}
+
+	readyToServe := false
+
+	// do specialization in other goroutine to prevent blocking in newdeploy
+	go func() {
+		if *specializeOnStart {
+			var specializeReq types.FunctionSpecializeRequest
+
+			err := json.Unmarshal([]byte(*specializePayload), &specializeReq)
+			if err != nil {
+				logger.Fatal("error decoding specialize request", zap.Error(err))
+			}
+
+			ctx := context.Background()
+			err = f.SpecializePod(ctx, specializeReq.FetchReq, specializeReq.LoadReq)
+			if err != nil {
+				logger.Fatal("error specializing function pod", zap.Error(err))
+			}
+
+			readyToServe = true
+		}
+	}()
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/fetch", f.FetchHandler)
+	mux.HandleFunc("/specialize", f.SpecializeHandler)
+	mux.HandleFunc("/upload", f.UploadHandler)
+	mux.HandleFunc("/version", f.VersionHandler)
+	mux.HandleFunc("/readniess-healthz", func(w http.ResponseWriter, r *http.Request) {
+		if !*specializeOnStart || readyToServe {
+			w.WriteHeader(http.StatusOK)
+		} else {
+			w.WriteHeader(http.StatusServiceUnavailable)
+		}
+	})
+	mux.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	})
+
+	logger.Info("fetcher ready to receive requests")
+	http.ListenAndServe(":8000", &ochttp.Handler{
+		Handler: mux,
+	})
+}
+
+func fetcherUsage() {
+	fmt.Println("Usage: fetcher [-specialize-on-startup] [-specialize-request <json>] [-secret-dir <string>] [-cfgmap-dir <string>] <shared volume path>")
+}