How to deploy a SpringBoot REST Application to Google App Engine?

Question

Tried

Subscribed trial for GoogleAppEngine.

1. INSTALLED GOOGLE APP ENGINE SDK
2. Downloaded the sample Java started code and deployed it. Working fine.
3. Used $appcfg.sh -A <appname> update target/appengine-try-java-1.0 to deploy
4. In this case, its a folder with all the webapp related stuffs

Question

In my case, I have a spring boot application which generates a jar file. It runs with a embedded container and I believe Google may have an alternate to deploy using Docker or some other way. But how?

There is no pointer or any details on how to run this in Google managed platform as far as I searched.

Any help or reference to documentation!! Alternates??

Answer 1

You can now use Google App Engine Java Flexible Environment - Java 8 Runtime :

https://cloud.google.com/appengine/docs/flexible/java/dev-java-only

It is Docker based

UPDATE:

You can now use Java 8 in App Engine Standard Environment :

• Tutorial: https://codelabs.developers.google.com/codelabs/cloud-app-engine-springboot/index.html

• Example: https://github.com/GoogleCloudPlatform/getting-started-java/tree/master/appengine-standard-java8/springboot-appengine-standard

• Blog post: https://cloudplatform.googleblog.com/2017/09/Java-8-on-App-Engine-Standard-environment-is-now-generally-available.html

Answer 2

Google App Engine still uses Servlet 2.5 that is below the requirements of Spring Boot (ie Servlet 3.0).

There is a way to workaround that, check the documentation for more details

Answer 3

Spring Boot requires Servlet 3.0 which GAE does not have. WorkAround is to have a " spring-boot-legacy " dependency. You can check further how to implement: https://github.com/scratches/spring-boot-sample-gae