Adding caching to profile images to master (#5428)

* Adding caching to profile images

* Fixing break

* Adding back in failed read

* Fixing build break

* Fixing break

api/user.go

@@ -590,26 +590,33 @@ func getAudits(c *Context, w http.ResponseWriter, r *http.Request) {
 func getProfileImage(c *Context, w http.ResponseWriter, r *http.Request) {
 	params := mux.Vars(r)
 	id := params["user_id"]
+	readFailed := false
 
 	var etag string
 
-	if user, err := app.GetUser(id); err != nil {
+	if users, err := app.GetUsersByIds([]string{id}, false); err != nil {
 		c.Err = err
 		return
 	} else {
+		if len(users) == 0 {
+			c.Err = model.NewLocAppError("getProfileImage", "store.sql_user.get_profiles.app_error", nil, "")
+			return
+		}
+
+		user := users[0]
 		etag = strconv.FormatInt(user.LastPictureUpdate, 10)
 		if HandleEtag(etag, "Profile Image", w, r) {
 			return
 		}
 
 		var img []byte
-		img, err = app.GetProfileImage(user)
+		img, readFailed, err = app.GetProfileImage(user)
 		if err != nil {
 			c.Err = err
 			return
 		}
 
-		if c.Session.UserId == id {
+		if readFailed {
 			w.Header().Set("Cache-Control", "max-age=300, public") // 5 mins
 		} else {
 			w.Header().Set("Cache-Control", "max-age=86400, public") // 24 hrs

app/user.go

@@ -667,25 +667,28 @@ func CreateProfileImage(username string, userId string) ([]byte, *model.AppError
 	}
 }
 
-func GetProfileImage(user *model.User) ([]byte, *model.AppError) {
+func GetProfileImage(user *model.User) ([]byte, bool, *model.AppError) {
 	var img []byte
+	readFailed := false
 
 	if len(utils.Cfg.FileSettings.DriverName) == 0 {
 		var err *model.AppError
 		if img, err = CreateProfileImage(user.Username, user.Id); err != nil {
-			return nil, err
+			return nil, false, err
 		}
 	} else {
 		path := "users/" + user.Id + "/profile.png"
 
 		if data, err := ReadFile(path); err != nil {
+			readFailed = true
+
 			if img, err = CreateProfileImage(user.Username, user.Id); err != nil {
-				return nil, err
+				return nil, false, err
 			}
 
 			if user.LastPictureUpdate == 0 {
 				if err := WriteFile(img, path); err != nil {
-					return nil, err
+					return nil, false, err
 				}
 			}
 
@@ -694,7 +697,7 @@ func GetProfileImage(user *model.User) ([]byte, *model.AppError) {
 		}
 	}
 
-	return img, nil
+	return img, readFailed, nil
 }
 
 func SetProfileImage(userId string, imageData *multipart.FileHeader) *model.AppError {