chore: support multi daemons e2e test (#896)

Signed-off-by: Jim Ma <majinjing3@gmail.com>

.github/workflows/compatibility-e2e.yml

@@ -17,6 +17,7 @@ env:
   DRAGONFLY_CHARTS_PATH: deploy/helm-charts/charts/dragonfly
   DRAGONFLY_CHARTS_CONFIG_PATH: test/testdata/charts/config.yaml
   DRAGONFLY_FILE_SERVER_PATH: test/testdata/k8s/file-server.yaml
+  DRAGONFLY_PROXY_SERVER_PATH: test/testdata/k8s/proxy.yaml
 
 jobs:
   compatibility_e2e_tests:
@@ -51,7 +52,7 @@ jobs:
 
       - name: Build images
         run: |
-          make docker-build
+          make docker-build docker-build-testing-tools
           docker pull dragonflyoss/${{ matrix.module }}:${{ env.DRAGONFLY_STABLE_IMAGE_TAG }}
 
       - name: Prepare kind environment
@@ -63,7 +64,12 @@ jobs:
         run: |
           helm install --wait --timeout 10m --dependency-update --create-namespace --namespace dragonfly-system --set ${{ matrix.module }}.tag=${{ env.DRAGONFLY_STABLE_IMAGE_TAG }} --set ${{ matrix.module }}.image=dragonflyoss/${{ matrix.module }} -f ${{ env.DRAGONFLY_CHARTS_CONFIG_PATH }} dragonfly ${{ env.DRAGONFLY_CHARTS_PATH }}
           kubectl apply -f ${{ env.DRAGONFLY_FILE_SERVER_PATH }}
+          kubectl apply -f ${{ env.DRAGONFLY_PROXY_SERVER_PATH }}
           kubectl wait po file-server-0 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
+          kubectl wait po file-server-no-content-length-0 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
+          kubectl wait po proxy-0 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
+          kubectl wait po proxy-1 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
+          kubectl wait po proxy-2 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
 
       - name: Run Compatibility E2E test
         env:

.github/workflows/e2e.yml

@@ -16,6 +16,7 @@ env:
   DRAGONFLY_CHARTS_PATH: deploy/helm-charts/charts/dragonfly
   DRAGONFLY_CHARTS_CONFIG_PATH: test/testdata/charts/config.yaml
   DRAGONFLY_FILE_SERVER_PATH: test/testdata/k8s/file-server.yaml
+  DRAGONFLY_PROXY_SERVER_PATH: test/testdata/k8s/proxy.yaml
 
 jobs:
   e2e_tests:
@@ -45,7 +46,7 @@ jobs:
           config: ${{ env.KIND_CONFIG_PATH }}
 
       - name: Build images
-        run: make docker-build
+        run: make docker-build docker-build-testing-tools
 
       - name: Prepare kind environment
         run: make kind-load
@@ -54,7 +55,12 @@ jobs:
         run: |
           helm install --wait --timeout 10m --dependency-update --create-namespace --namespace dragonfly-system -f ${{ env.DRAGONFLY_CHARTS_CONFIG_PATH }} dragonfly ${{ env.DRAGONFLY_CHARTS_PATH }}
           kubectl apply -f ${{ env.DRAGONFLY_FILE_SERVER_PATH }}
+          kubectl apply -f ${{ env.DRAGONFLY_PROXY_SERVER_PATH }}
           kubectl wait po file-server-0 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
+          kubectl wait po file-server-no-content-length-0 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
+          kubectl wait po proxy-0 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
+          kubectl wait po proxy-1 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
+          kubectl wait po proxy-2 --namespace dragonfly-e2e --for=condition=ready --timeout=10m
 
       - name: Run E2E test
         run: make actions-e2e-test-coverage

Makefile

@@ -62,6 +62,12 @@ docker-build-manager:
 	./hack/docker-build.sh manager
 .PHONY: docker-build-manager
 
+# Build testing tools image
+docker-build-testing-tools: build-dirs
+	@echo "Begin to testing tools image."
+	./test/tools/no-content-length/build.sh
+.PHONY: docker-build-testing-tools
+
 # Push cdn image
 docker-push-cdn: docker-build-cdn
 	@echo "Begin to push cdn docker image."
@@ -218,9 +224,9 @@ clean-e2e-test:
 .PHONY: clean-e2e-test
 
 # Kind load dragonlfy
-kind-load: kind-load-cdn kind-load-scheduler kind-load-dfdaemon kind-load-manager
+kind-load: kind-load-cdn kind-load-scheduler kind-load-dfdaemon kind-load-manager kind-load-testing-tools
 	@echo "Kind load image done."
-.PHONY: docker-build
+.PHONY: kind-load
 
 # Run kind load docker-image cdn
 kind-load-cdn:
@@ -242,6 +248,11 @@ kind-load-manager:
 	@./hack/kind-load.sh manager
 .PHONY: kind-load-manager
 
+# Run kind load docker testing tools
+kind-load-testing-tools:
+	@./hack/kind-load.sh no-content-length
+.PHONY: kind-load-testing-tools
+
 # Run code lint
 lint: markdownlint
 	@echo "Begin to golangci-lint."
@@ -302,11 +313,12 @@ help:
 	@echo "make e2e-test                       run e2e tests"
 	@echo "make e2e-test-coverage              run e2e tests with coverage"
 	@echo "make clean-e2e-test                 clean e2e tests"
-	@echo "make kind-load-image                kind load docker image"
+	@echo "make kind-load                      kind load docker image"
 	@echo "make kind-load-cdn                  kind load cdn docker image"
 	@echo "make kind-load-scheduler            kind load scheduler docker image"
 	@echo "make kind-load-dfdaemon             kind load dfdaemon docker image"
 	@echo "make kind-load-manager              kind load manager docker image"
+	@echo "make kind-load-testing-tools        kind load testing tools docker image"
 	@echo "make lint                           run code lint"
 	@echo "make markdownlint                   run markdown lint"
 	@echo "make swag                           generate swagger api docs"

client/daemon/peer/peertask_stream.go

@@ -379,15 +379,7 @@ func (s *streamPeerTask) backSource() {
 	defer backSourceSpan.End()
 	s.contentLength.Store(-1)
 	_ = s.callback.Init(s)
-	reportPieceCtx, reportPieceSpan := tracer.Start(backSourceCtx, config.SpanReportPieceResult)
+	err := s.pieceManager.DownloadSource(backSourceCtx, s, s.request)
-	defer reportPieceSpan.End()
-	if peerPacketStream, err := s.schedulerClient.ReportPieceResult(reportPieceCtx, s.taskID, s.request); err != nil {
-		logger.Errorf("step 2: peer %s report piece failed: err", s.request.PeerId, err)
-	} else {
-		s.peerPacketStream = peerPacketStream
-	}
-	logger.Infof("step 2: start report peer %s back source piece result", s.request.PeerId)
-	err := s.pieceManager.DownloadSource(s.ctx, s, s.request)
 	if err != nil {
 		s.Errorf("download from source error: %s", err)
 		s.failedReason = err.Error()

hack/install-e2e-test.sh

@@ -7,6 +7,7 @@ set -o pipefail
 KIND_CONFIG_PATH="test/testdata/kind/config.yaml"
 CHARTS_CONFIG_PATH="test/testdata/charts/config.yaml"
 FILE_SERVER_CONFIG_PATH="test/testdata/k8s/file-server.yaml"
+PROXY_SERVER_CONFIG_PATH="test/testdata/k8s/proxy.yaml"
 CHARTS_PATH="deploy/helm-charts/charts/dragonfly"
 NAMESPACE="dragonfly-system"
 E2E_NAMESPACE="dragonfly-e2e"
@@ -41,6 +42,22 @@ install-file-server() {
   kubectl wait --namespace ${E2E_NAMESPACE} \
     --for=condition=ready pod ${FILE_SERVER_NAME} \
     --timeout=10m
+  kubectl wait --namespace ${E2E_NAMESPACE} \
+    --for=condition=ready pod file-server-no-content-length-0 \
+    --timeout=10m
+}
+
+install-proxy-server() {
+  kubectl apply -f ${PROXY_SERVER_CONFIG_PATH}
+  kubectl wait --namespace ${E2E_NAMESPACE} \
+    --for=condition=ready pod proxy-0 \
+    --timeout=10m
+  kubectl wait --namespace ${E2E_NAMESPACE} \
+    --for=condition=ready pod proxy-1 \
+    --timeout=10m
+  kubectl wait --namespace ${E2E_NAMESPACE} \
+    --for=condition=ready pod proxy-2 \
+    --timeout=10m
 }
 
 install-ginkgo() {
@@ -72,7 +89,7 @@ main() {
   install-kind
 
   print_step_info "start building docker images"
-  make docker-build
+  make docker-build docker-build-testing-tools
 
   print_step_info "start loading image for kind"
   make kind-load
@@ -83,6 +100,9 @@ main() {
   print_step_info "start install file server"
   install-file-server
 
+  print_step_info "start install proxy server"
+  install-proxy-server
+
   print_step_info "start install ginkgo"
   install-ginkgo
 

hack/kind-load.sh

@@ -24,6 +24,9 @@ main() {
         ;;
     manager)
         kind-load manager
+        ;;
+    no-content-length)
+        kind-load no-content-length
     esac
 }
 

test/e2e/dfget_test.go

@@ -19,6 +19,7 @@ package e2e
 import (
 	"fmt"
 	"strings"
+	"time"
 
 	. "github.com/onsi/ginkgo" //nolint
 	. "github.com/onsi/gomega" //nolint
@@ -26,40 +27,88 @@ import (
 	"d7y.io/dragonfly/v2/test/e2e/e2eutil"
 )
 
-var _ = Describe("Download with dfget", func() {
+var _ = Describe("Download with dfget and proxy", func() {
 	Context("dfget", func() {
-		It("dfget download should be ok", func() {
+		singleDfgetTest("dfget daemon download should be ok",
-			out, err := e2eutil.KubeCtlCommand("-n", dragonflyNamespace, "get", "pod", "-l", "component=dfdaemon",
+			dragonflyNamespace, "component=dfdaemon",
+			"dragonfly-dfdaemon-", "dfdaemon")
+		for i := 0; i < 3; i++ {
+			singleDfgetTest(
+				fmt.Sprintf("dfget daemon proxy-%d should be ok", i),
+				dragonflyE2ENamespace,
+				fmt.Sprintf("statefulset.kubernetes.io/pod-name=proxy-%d", i),
+				"proxy-", "proxy")
+		}
+	})
+})
+
+func singleDfgetTest(name, ns, label, podNamePrefix, container string) {
+	It(name, func() {
+		out, err := e2eutil.KubeCtlCommand("-n", ns, "get", "pod", "-l", label,
 			"-o", "jsonpath='{range .items[*]}{.metadata.name}{end}'").CombinedOutput()
 		podName := strings.Trim(string(out), "'")
 		Expect(err).NotTo(HaveOccurred())
-			fmt.Println(podName)
+		fmt.Println("test in pod: " + podName)
-			Expect(strings.HasPrefix(podName, "dragonfly-dfdaemon-")).Should(BeTrue())
+		Expect(strings.HasPrefix(podName, podNamePrefix)).Should(BeTrue())
-			pod := e2eutil.NewPodExec(dragonflyNamespace, podName, "dfdaemon")
+		pod := e2eutil.NewPodExec(ns, podName, container)
 
+		var urls = map[string]string{}
 		for _, v := range e2eutil.GetFileList() {
-				url := e2eutil.GetFileURL(v)
+			urls[e2eutil.GetFileURL(v)] = v
-				fmt.Println("download url " + url)
+			urls[e2eutil.GetNoContentLengthFileURL(v)] = v
+		}
 
+		for url, path := range urls {
+			fmt.Println("download url: " + url)
 			// get original file digest
-				out, err = e2eutil.DockerCommand("sha256sum", v).CombinedOutput()
+			out, err = e2eutil.DockerCommand("sha256sum", path).CombinedOutput()
-				fmt.Println(string(out))
+			fmt.Println("original sha256sum: " + string(out))
 			Expect(err).NotTo(HaveOccurred())
 			sha256sum1 := strings.Split(string(out), " ")[0]
 
-				// download file
+			var (
+				start time.Time
+				end   time.Time
+			)
+			// download file via dfget
+			start = time.Now()
 			out, err = pod.Command("dfget", "-O", "/tmp/d7y.out", url).CombinedOutput()
+			end = time.Now()
 			fmt.Println(string(out))
 			Expect(err).NotTo(HaveOccurred())
 
-				// get downloaded file digest
+			// get dfget downloaded file digest
 			out, err = pod.Command("sha256sum", "/tmp/d7y.out").CombinedOutput()
-				fmt.Println(string(out))
+			fmt.Println("dfget sha256sum: " + string(out))
 			Expect(err).NotTo(HaveOccurred())
 			sha256sum2 := strings.Split(string(out), " ")[0]
-
 			Expect(sha256sum1).To(Equal(sha256sum2))
+
+			// slow download
+			Expect(end.Sub(start).Seconds() < 30.0).To(Equal(true))
+
+			// skip dfdaemon
+			if ns == dragonflyNamespace {
+				continue
+			}
+			// download file via proxy
+			start = time.Now()
+			out, err = pod.Command("sh", "-c", fmt.Sprintf(`
+              export http_proxy=http://127.0.0.1:65001
+              wget -O /tmp/wget.out %s`, url)).CombinedOutput()
+			end = time.Now()
+			fmt.Println(string(out))
+			Expect(err).NotTo(HaveOccurred())
+
+			// get proxy downloaded file digest
+			out, err = pod.Command("sha256sum", "/tmp/wget.out").CombinedOutput()
+			fmt.Println("wget sha256sum: " + string(out))
+			Expect(err).NotTo(HaveOccurred())
+			sha256sum3 := strings.Split(string(out), " ")[0]
+			Expect(sha256sum1).To(Equal(sha256sum3))
+
+			// slow download
+			Expect(end.Sub(start).Seconds() < 30.0).To(Equal(true))
 		}
 	})
-	})
+}
-})

test/e2e/e2e_test.go

@@ -33,6 +33,7 @@ const (
 	proxy                 = "localhost:65001"
 	hostnameFilePath      = "/etc/hostname"
 	dragonflyNamespace    = "dragonfly-system"
+	dragonflyE2ENamespace = "dragonfly-e2e"
 )
 
 const (

test/e2e/e2eutil/file_server.go

@@ -40,3 +40,8 @@ func GetFileURL(filePath string) string {
 	baseURL := "http://file-server.dragonfly-e2e.svc/kind"
 	return fmt.Sprintf("%s%s", baseURL, filePath)
 }
+
+func GetNoContentLengthFileURL(filePath string) string {
+	baseURL := "http://file-server-no-content-length.dragonfly-e2e.svc/kind"
+	return fmt.Sprintf("%s%s", baseURL, filePath)
+}

test/e2e/manager/preheat.go

@@ -48,11 +48,11 @@ var _ = Describe("Preheat with manager", func() {
 
 			for _, v := range e2eutil.GetFileList() {
 				url := e2eutil.GetFileURL(v)
-				fmt.Println("download url " + url)
+				fmt.Println("download url: " + url)
 
 				// get original file digest
 				out, err := e2eutil.DockerCommand("sha256sum", v).CombinedOutput()
-				fmt.Println(string(out))
+				fmt.Println("original sha256sum: " + string(out))
 				Expect(err).NotTo(HaveOccurred())
 				sha256sum1 := strings.Split(string(out), " ")[0]
 
@@ -92,7 +92,7 @@ var _ = Describe("Preheat with manager", func() {
 
 		It("preheat image should be ok", func() {
 			url := "https://registry-1.docker.io/v2/library/alpine/manifests/3.14"
-			fmt.Println("download image " + url)
+			fmt.Println("download image: " + url)
 
 			var (
 				cdnTaskIDs = []string{
@@ -145,7 +145,7 @@ var _ = Describe("Preheat with manager", func() {
 		It("concurrency 100 preheat should be ok", func() {
 			// generate the data file
 			url := e2eutil.GetFileURL(hostnameFilePath)
-			fmt.Println("download url " + url)
+			fmt.Println("download url: " + url)
 			dataFilePath := "post_data"
 			fd, err := os.Create(dataFilePath)
 			Expect(err).NotTo(HaveOccurred())
@@ -162,7 +162,7 @@ var _ = Describe("Preheat with manager", func() {
 
 			// get original file digest
 			out, err = e2eutil.DockerCommand("sha256sum", hostnameFilePath).CombinedOutput()
-			fmt.Println(string(out))
+			fmt.Println("original sha256sum: " + string(out))
 			Expect(err).NotTo(HaveOccurred())
 			sha256sum1 := strings.Split(string(out), " ")[0]
 
@@ -259,10 +259,9 @@ func checkPreheatResult(cdnPods [3]*e2eutil.PodExec, cdnTaskID string) string {
 
 		// calculate digest of downloaded file
 		out, err = cdn.Command("sha256sum", fmt.Sprintf("%s/%s/%s", cdnCachePath, dir, file)).CombinedOutput()
-		fmt.Println(string(out))
+		fmt.Println("preheat sha256sum: " + string(out))
 		Expect(err).NotTo(HaveOccurred())
 		sha256sum2 = strings.Split(string(out), " ")[0]
-		fmt.Println(string(sha256sum2))
 		break
 	}
 	return sha256sum2

test/testdata/k8s/file-server.yaml

@@ -4,6 +4,7 @@ metadata:
   name: dragonfly-e2e
 
 ---
+
 apiVersion: v1
 kind: Service
 metadata:
@@ -21,6 +22,7 @@ spec:
     targetPort: 80
 
 ---
+
 apiVersion: apps/v1
 kind: StatefulSet
 metadata:
@@ -53,3 +55,55 @@ spec:
       - name: files
         hostPath:
           path: /
+
+---
+
+apiVersion: v1
+kind: Service
+metadata:
+  name: file-server-no-content-length
+  namespace: dragonfly-e2e
+spec:
+  selector:
+    app: dragonfly
+    component: file-server-no-content-length
+  type: ClusterIP
+  ports:
+  - name: server
+    port: 80
+    protocol: TCP
+    targetPort: 80
+
+---
+
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: file-server-no-content-length
+  namespace: dragonfly-e2e
+spec:
+  serviceName: file-server-no-content-length
+  selector:
+    matchLabels:
+      app: dragonfly
+      component: file-server-no-content-length
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        app: dragonfly
+        component: file-server-no-content-length
+    spec:
+      containers:
+      - name: server
+        image: d7yio/no-content-length:latest
+        imagePullPolicy: "IfNotPresent"
+        ports:
+        - containerPort: 80
+        volumeMounts:
+        - name: files
+          mountPath: /static/kind
+      volumes:
+      - name: files
+        hostPath:
+          path: /

test/testdata/k8s/proxy.yaml

@@ -0,0 +1,132 @@
+kind: ConfigMap
+apiVersion: v1
+metadata:
+  name: proxy
+  namespace: dragonfly-e2e
+data:
+  dfget.yaml: |-
+    aliveTime: 0s
+    gcInterval: 1m0s
+    keepStorage: false
+    dataDir: /root/.dragonfly/dfget-daemon/
+    workDir: /root/.dragonfly/dfget-daemon/
+    verbose: true
+    pprof-port: 0
+    scheduler:
+      manager:
+        enable: true
+        netAddrs:
+        - type: tcp
+          addr: dragonfly-manager.dragonfly-system.svc.cluster.local:65003
+        refreshInterval: 5m
+      scheduleTimeout: 30s
+      disableAutoBackSource: true
+    host:
+      advertiseIP: 0.0.0.0
+      idc: ""
+      listenIP: 0.0.0.0
+      location: ""
+      netTopology: ""
+      securityDomain: ""
+    download:
+      calculateDigest: true
+      downloadGRPC:
+        security:
+          insecure: true
+        unixListen:
+          socket: /tmp/dfdamon.sock
+      peerGRPC:
+        security:
+          insecure: true
+        tcpListen:
+          listen: 0.0.0.0
+          port: 65000
+      perPeerRateLimit: 100Mi
+      totalRateLimit: 200Mi
+    upload:
+      rateLimit: 100Mi
+      security:
+        insecure: true
+      tcpListen:
+        listen: 0.0.0.0
+        port: 65002
+    storage:
+      diskGCThreshold: 50Gi
+      multiplex: true
+      strategy: io.d7y.storage.v2.simple
+      taskExpireTime: 6h
+    proxy:
+      defaultFilter: Expires&Signature
+      tcpListen:
+        listen: 0.0.0.0
+        port: 65001
+      security:
+        insecure: true
+      registryMirror:
+        dynamic: true
+        insecure: false
+        url: https://index.docker.io
+      proxies:
+        - regx: blobs/sha256.*
+        - regx: file-server
+
+---
+
+apiVersion: v1
+kind: Service
+metadata:
+  name: proxy
+  namespace: dragonfly-e2e
+spec:
+  selector:
+    app: dragonfly
+    component: proxy
+  type: ClusterIP
+  ports:
+  - name: proxy
+    port: 65001
+    protocol: TCP
+    targetPort: 65001
+
+---
+
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: proxy
+  namespace: dragonfly-e2e
+spec:
+  serviceName: proxy
+  selector:
+    matchLabels:
+      app: dragonfly
+      component: proxy
+  replicas: 3
+  template:
+    metadata:
+      labels:
+        app: dragonfly
+        component: proxy
+    spec:
+      containers:
+      - name: proxy
+        image: d7yio/dfdaemon:latest
+        imagePullPolicy: "IfNotPresent"
+        ports:
+        - containerPort: 65001
+        volumeMounts:
+        - mountPath: /etc/dragonfly
+          name: config
+        - mountPath: /var/log/dragonfly/daemon
+          name: logs
+        - mountPath: /root/.dragonfly/dfget-daemon/
+          name: data
+      volumes:
+      - configMap:
+          defaultMode: 420
+          name: proxy
+        name: config
+      - emptyDir: {}
+        name: data
+      - emptyDir: {}
+        name: logs

test/tools/no-content-length/Dockerfile

@@ -0,0 +1,24 @@
+ARG BASE_IMAGE=alpine:3.14
+
+FROM golang:1.17.3-alpine3.14 as builder
+
+COPY . /go/src/
+
+ARG GOPROXY
+ARG GOTAGS
+ARG GOGCFLAGS
+
+RUN cd /go/src/ && GO111MODULE=off go build -o /tmp/no-content-length .
+
+FROM ${BASE_IMAGE}
+
+COPY --from=builder /tmp/no-content-length /usr/local/bin/
+
+RUN echo "hosts: files dns" > /etc/nsswitch.conf
+
+EXPOSE 80
+
+WORKDIR /
+
+ENTRYPOINT ["/usr/local/bin/no-content-length"]
+

test/tools/no-content-length/build.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+docker build -t "${D7Y_REGISTRY:-d7yio}/no-content-length:${D7Y_VERSION:-latest}" \
+  -f test/tools/no-content-length/Dockerfile \
+  test/tools/no-content-length

test/tools/no-content-length/main.go

@@ -0,0 +1,87 @@
+/*
+ *     Copyright 2020 The Dragonfly Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+)
+
+var port = flag.Int("port", 80, "")
+
+func main() {
+	http.Handle("/", &fileHandler{dir: "/static"})
+	fmt.Printf("listen on %d", *port)
+	err := http.ListenAndServe(fmt.Sprintf(":%d", *port), nil)
+	if err != nil {
+		panic(err)
+	}
+}
+
+type fileHandler struct {
+	dir                 string
+	enableContentLength bool
+}
+
+func (f *fileHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	upath := filepath.Clean(r.URL.Path)
+	if !strings.HasPrefix(upath, "/") {
+		upath = "/" + upath
+		r.URL.Path = upath
+	}
+
+	filePath := path.Join(f.dir, upath)
+	if !strings.HasPrefix(filePath, f.dir) {
+		w.WriteHeader(http.StatusBadRequest)
+		_, _ = w.Write([]byte(fmt.Sprintf("target is not in correct dir")))
+		return
+	}
+	fileInfo, err := os.Stat(filePath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			w.WriteHeader(http.StatusNotFound)
+		} else {
+			w.WriteHeader(http.StatusInternalServerError)
+		}
+		_, _ = w.Write([]byte(fmt.Sprintf("%s", err)))
+		return
+	}
+	if fileInfo.IsDir() {
+		// todo list files
+		w.WriteHeader(http.StatusBadRequest)
+		_, _ = w.Write([]byte(fmt.Sprintf("target is dir not file")))
+		return
+	}
+	file, err := os.Open(filePath)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		_, _ = w.Write([]byte(fmt.Sprintf("%s", err)))
+		return
+	}
+	defer file.Close()
+
+	if f.enableContentLength {
+		w.Header().Set("Content-Length", fmt.Sprintf("%d", fileInfo.Size()))
+	}
+	_, _ = io.Copy(w, file)
+}