create letters postbox

task3-backend/config/task3.yaml

@@ -5,6 +5,9 @@ httpApi:
 task:
   addr: "0.0.0.0:31337"
   clients: 4
+  letterPath: "./letter"
+  localPostboxPath: "./postbox"
+  remotePostboxPath: "/root/a-quest/deploy/task3/postbox"
 
 redis:
   addr: "localhost:6379"

task3-backend/lib/conf.go

@@ -13,6 +13,9 @@ type AppConfig struct {
 	Task struct {
 		Addr              string `mapstructure:"addr"`
 		Clients           int    `mapstructure:"clients"`
+		LetterPath        string `mapstructure:"letterPath"`
+		LocalPostboxPath  string `mapstructure:"localPostboxPath"`
+		RemotePostboxPath string `mapstructure:"remotePostboxPath"`
 	} `mapstructure:"task"`
 	Redis struct {
 		Addr       string `mapstructure:"addr"`

task3-backend/lib/server.go

@@ -27,6 +27,8 @@ import (
 
 type Server struct {
 	LetterPath        string
+	LocalPostboxPath  string
+	RemotePostboxPath string
 
 	Alg  string
 	Pub  *ecdsa.PublicKey
@@ -179,11 +181,12 @@ func (s *Server) readKey(conn net.Conn) (key string, err error) {
 
 func (s *Server) createJail(now int64, claims *jwtgo.StandardClaims) (id string, err error) {
 
-	letterPath, letterFullPath, err := createLetterProtected(s.LetterPath)
+	letterPath, _, err := s.createLetter()
 	if err != nil {
 		return
 	}
 
+	remoteLetterPath := path.Join(s.RemotePostboxPath, letterPath)
 	name := fmt.Sprintf("%d-%s", now, claims.Id)
 	cfg := &container.Config{
 		NetworkDisabled: true,
@@ -198,7 +201,7 @@ func (s *Server) createJail(now int64, claims *jwtgo.StandardClaims) (id string,
 	}
 	letter := mount.Mount{
 		Type:   mount.TypeBind,
-		Source: letterFullPath,
+		Source: remoteLetterPath,
 		Target: fmt.Sprintf("/%s", letterPath),
 	}
 	hcfg := &container.HostConfig{
@@ -280,6 +283,33 @@ Proxying:
 	return
 }
 
+func (s *Server) createLetter() (letterPath string, localFullPath string, err error) {
+
+	source, err := os.Open(s.LetterPath)
+	if err != nil {
+		return
+	}
+	defer source.Close()
+
+	letterPath = fmt.Sprintf("%s.letter", uuid.New().String())
+	localFullPath = path.Join(s.LocalPostboxPath, letterPath)
+
+	letter, err := os.OpenFile(localFullPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0000)
+	if err != nil {
+		return
+	}
+	defer letter.Close()
+
+	_, err = io.Copy(letter, source)
+	if err != nil {
+		return
+	}
+
+	_ = unix.Sync()
+
+	return
+}
+
 func createProxyChan(conn net.Conn, closed *uint32) (out chan []byte) {
 
 	out = make(chan []byte)
@@ -316,31 +346,3 @@ func createProxyChan(conn net.Conn, closed *uint32) (out chan []byte) {
 
 	return
 }
-
-func createLetterProtected(sourcePath string) (letterPath string, letterFullPath string, err error) {
-
-	source, err := os.Open(sourcePath)
-	if err != nil {
-		return
-	}
-	defer source.Close()
-
-	tmpPath := os.TempDir()
-	letterPath = fmt.Sprintf("%s.letter", uuid.New().String())
-	letterFullPath = path.Join(tmpPath, letterPath)
-
-	letter, err := os.OpenFile(letterFullPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0000)
-	if err != nil {
-		return
-	}
-	defer letter.Close()
-
-	_, err = io.Copy(letter, source)
-	if err != nil {
-		return
-	}
-
-	_ = unix.Sync()
-
-	return
-}

task3-backend/main.go

@@ -116,6 +116,9 @@ func main() {
 		WinnersKey:        Config.Redis.WinnersKey,
 		Redis:             rediclient,
 		ClientsLimit:      uint32(Config.Task.Clients),
+		LetterPath:        Config.Task.LetterPath,
+		LocalPostboxPath:  Config.Task.LocalPostboxPath,
+		RemotePostboxPath: Config.Task.RemotePostboxPath,
 	}
 
 	go httpStart(apiserv)