prefetch separate fanotify nydus-snapshotter side

config/config.go

@@ -209,6 +209,11 @@ type SystemControllerConfig struct {
 	DebugConfig DebugConfig `toml:"debug"`
 }
 
+type PrefetchControllerConfig struct {
+	Enable         bool   `toml:"enable"`
+	PrefetchConfig string `toml:"get_prefetch_endpoint"`
+}
+
 type SnapshotterConfig struct {
 	// Configuration format version
 	Version int `toml:"version"`
@@ -229,6 +234,8 @@ type SnapshotterConfig struct {
 	LoggingConfig          LoggingConfig          `toml:"log"`
 	CgroupConfig           CgroupConfig           `toml:"cgroup"`
 	Experimental           Experimental           `toml:"experimental"`
+	// Get prefetch list from http server
+	PrefetchControllerConfig PrefetchControllerConfig `toml:"prefetch"`
 }
 
 func LoadSnapshotterConfig(path string) (*SnapshotterConfig, error) {

config/global.go

@@ -69,6 +69,14 @@ func GetPrefetchRoot() string {
 	return globalConfig.PrefetchRoot
 }
 
+func GetPrefetchEndpoint() string {
+	return globalConfig.origin.PrefetchControllerConfig.PrefetchConfig
+}
+
+func IsPrefetchEnabled() bool {
+	return globalConfig.origin.PrefetchControllerConfig.Enable
+}
+
 func GetMirrorsConfigDir() string {
 	return globalConfig.MirrorsConfig.Dir
 }

misc/snapshotter/config.toml

@@ -9,6 +9,10 @@ daemon_mode = "dedicated"
 # Whether snapshotter should try to clean up resources when it is closed
 cleanup_on_close = false
 
+[prefetch]
+enable = false
+get_prefetch_endpoint = "http://localhost:1323/api/v1/prefetch/download"
+
 [system]
 # Snapshotter's debug and trace HTTP server interface
 enable = true

pkg/daemon/config.go

@@ -36,7 +36,7 @@ func WithPrefetchDir(dir, imageID string) NewDaemonOpt {
 	return func(d *Daemon) error {
 		s := filepath.Join(dir, d.ID())
 		prefetchDir, err := prefetch.GetPrefetchList(s, imageID)
-		if err != nil && !errors.Is(err, prefetch.ErrUds) {
+		if err != nil {
 			return errors.Wrapf(err, "failed to get prefetchList for image %s in path %s", imageID, s)
 		}
 		if prefetchDir != "" {

pkg/prefetch/prefetch.go

@@ -7,72 +7,56 @@
 package prefetch
 
 import (
-	"context"
 	"encoding/json"
 	"fmt"
 	"io"
-	"net"
 	"net/http"
 	"os"
 	"path/filepath"
 	"strings"
 
 	"github.com/containerd/containerd/log"
 	"github.com/pkg/errors"
+
+	"github.com/containerd/nydus-snapshotter/config"
 )
 
 type prefetchlist struct {
 	FilePaths []string `json:"files"`
 }
 
-const (
-	endpointPrefetch = "/api/v1/imagename"
-	udsSocket        = "/run/optimizer/prefetch.sock"
-)
-
-var ErrUds = errors.New("failed to connect unix domain socket")
-
 func GetPrefetchList(prefetchDir, imageRepo string) (string, error) {
-	url := fmt.Sprintf("http://unix%s", endpointPrefetch)
-
-	req, err := http.NewRequest(http.MethodPost, url, strings.NewReader(imageRepo))
-	if err != nil {
-		return "", err
-	}
+	if config.IsPrefetchEnabled() {
+		url := config.GetPrefetchEndpoint()
+		getURL := fmt.Sprintf("%s?imageName=%s", url, imageRepo)
 
-	client := &http.Client{
-		Transport: &http.Transport{
-			DialContext: func(_ context.Context, _, _ string) (net.Conn, error) {
-				return net.Dial("unix", udsSocket)
-			},
-		},
-	}
-	resp, err := client.Do(req)
-	if err != nil {
-		log.L.Infof("failed to connect unix domain socket. Skipping prefetch for image: %s\n", imageRepo)
-		return "", ErrUds
-	}
-	defer resp.Body.Close()
+		resp, err := http.Get(getURL)
+		if err != nil {
+			return "", err
+		}
+		defer resp.Body.Close()
 
-	if resp.StatusCode != http.StatusOK {
-		return "", fmt.Errorf("failed to send data, status code: %v", resp.StatusCode)
-	}
+		if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusNotFound {
+			return "", fmt.Errorf("get from server returned a non-OK status code: %d, HTTP Status Error", resp.StatusCode)
+		}
 
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return "", err
-	}
+		body, err := io.ReadAll(resp.Body)
+		if err != nil {
+			return "", err
+		}
 
-	if strings.Contains(string(body), "CacheItem not found") {
-		log.L.Infof("Cache item not found for image: %s\n", imageRepo)
-		return "", nil
-	}
+		if strings.Contains(string(body), "CacheItem not found") {
+			log.L.Infof("Cache item not found for image: %s\n", imageRepo)
+			return "", nil
+		}
 
-	prefetchfilePath, err := storePrefetchList(prefetchDir, body)
-	if err != nil {
-		return "", err
+		prefetchfilePath, err := storePrefetchList(prefetchDir, body)
+		if err != nil {
+			return "", err
+		}
+		return prefetchfilePath, nil
 	}
-	return prefetchfilePath, nil
+	return "", nil
 }
 
 func storePrefetchList(prefetchDir string, list []byte) (string, error) {