Problem during deploying Metabase with Google App Engine

Question

I am following this instructions for deploying metabase with Google App Engine, after I complete the operations and open the url where the service is deployed i get 502 Bad Gateway or
Error: Server Error The server encountered a temporary error and could not complete your request. Please try again in 30 seconds. and from console I got
INFO metabase.driver :: Registered abstract driver :sql ?
This is my app.yaml

env: flex

manual_scaling:
   instances: 1

env_variables:
   MB_JETTY_PORT: 8080
   MB_DB_TYPE: postgres
   MB_DB_DBNAME: metabase
   MB_DB_PORT: 5432
   MB_DB_USER: devops
   MB_DB_PASS: password 
   MB_DB_HOST: 127.0.0.1

beta_settings:
   cloud_sql_instances: <instance-name>=tcp:5432

Dockerfile:

FROM gcr.io/google-appengine/openjdk

EXPOSE 8080

ENV PORT 8080
ENV MB_PORT 8080
ENV MB_JETTY_PORT 8080
ENV MB_DB_PORT 5432
ENV METABASE_SQL_INSTANCE <instance_name>=tcp:5432
ENV JAVA_OPTS "-XX:+IgnoreUnrecognizedVMOptions -Dfile.encoding=UTF-8 --add-opens=java.base/java.net=ALL-UNNAMED --add-modules=java.xml.bind"

ADD https://dl.google.com/cloudsql/cloud_sql_proxy.linux.amd64 ./cloud_sql_proxy
ADD http://downloads.metabase.com/v0.33.2/metabase.jar /metabase.jar

RUN chmod +x ./cloud_sql_proxy

CMD ./cloud_sql_proxy -instances=$METABASE_SQL_INSTANCE=tcp:$MB_DB_PORT & java -jar ./metabase.jar

Also I troubleshoot everything I saw on stackoverflow and tried all options with similar problem but still not working, i tried this option 1 and this options 2 but still no working effects.

My steps:
On GCP I am the owner of the project,I created Compute engine VM instance, then SQL Postgres instance, and a new Postgres database with user, I added the public IP address of the VM in the configurations of the SQL Instance as authorized network, and deployed the app.yaml and Dockerfile with gcloud app deploy. Any working solutons?

  [1]: https://www.cloudbooklet.com/install-metabase-on-google-cloud-with-docker-app-engine/ 

Answer 1

I fixed the issue. I just change the metabase version, it always has to be the newest. 0.36.6 at this moment