gcloud app deploy command error INVALID_ARGUMENT: WEB-INF/appengine-web.xml is required for this runtime

I try to convert work from appengine-web.xml file to work with app.yaml file in google app engine project, so I created app.yaml file and put it in main folder of project.
when I try to deploy my project with "gcloud app deploy" command
I get error
INVALID_ARGUMENT: WEB-INF/appengine-web.xml is required for this runtime
if I run "gcloud app deploy path/appengine-web.xml" command
the deploy is work fine
what i need to to convert to work with app.yaml file?
additions info
my project write in java8
my project write in eclipse

thank you

One Java Application that will be deployed in App Engine must have a file named appengine-web.xml in its WAR, in the directory WEB-INF/.

I verified the gcloud app deploy command documentation and it seems that for Java 8 you need to run :

<!-- language: lang-html -->

gcloud app deploy ~/my_app/WEB-INF/appengine-web.xml

<!-- end snippet -->

That is the one that you are running.

On the other hand, I found this documentation (for Flexible ) that mentions how to organize your files in case that you want to use the app.yaml for java 8

As the documetnatyion indicated that,for Java8 Standard apps, you must add the path to the appengine-web.xml file inside the WEB-INF directory. gcloud app deploy skips files specified in the .gcloudignore file see gcloud topic gcloudignore for more information.