add API endpoint to remove a app's image

api/application.go

@@ -358,6 +358,30 @@ func (a *ApplicationAPI) UploadApplicationImage(ctx *gin.Context) {
 	})
 }
 
+func (a *ApplicationAPI) RemoveApplicationImage(ctx *gin.Context) {
+	withID(ctx, "id", func(id uint) {
+		app, err := a.DB.GetApplicationByID(id)
+		if success := successOrAbort(ctx, 500, err); !success {
+			return
+		}
+		if app != nil && app.UserID == auth.GetUserID(ctx) {
+			if app.Image == "" {
+				ctx.AbortWithError(400, fmt.Errorf("app with id %d does not have a customized image", id))
+				return
+			}
+
+			app.Image = ""
+			if success := successOrAbort(ctx, 500, a.DB.UpdateApplication(app)); !success {
+				return
+			}
+			os.Remove(a.ImageDir + app.Image)
+			ctx.JSON(200, withResolvedImage(app))
+		} else {
+			ctx.AbortWithError(404, fmt.Errorf("app with id %d doesn't exists", id))
+		}
+	})
+}
+
 func withResolvedImage(app *model.Application) *model.Application {
 	if app.Image == "" {
 		app.Image = "static/defaultapp.png"

router/router.go

@@ -119,6 +119,8 @@ func Create(db *database.GormDatabase, vInfo *model.VersionInfo, conf *config.Co
 
 			app.POST("/:id/image", applicationHandler.UploadApplicationImage)
 
+			app.DELETE("/:id/image", applicationHandler.RemoveApplicationImage)
+
 			app.PUT("/:id", applicationHandler.UpdateApplication)
 
 			app.DELETE("/:id", applicationHandler.DeleteApplication)