Google AppEngine doesnt serve static resources

Question

I have a springboot application deployed into Google Cloud via AppEngine. I need to serve static resources out of appengine instances and I used this documentation: https://cloud.google.com/appengine/docs/standard/java11/serving-static-files .

The problem always (a lot of tests done) is (google cloud console error): "Static file referenced by handler not found"

I tested several configurations... but had no luck.

My app.yaml (last one):

runtime: "@appengine.runtime@"
env: "standard"
entrypoint: "java -noverify -jar myjar.jar -cp BOOT-INF/classes/:BOOT-INF/lib/* com.....config.Application"
instance_class: "@appengine.instance.class@"
inbound_services:
  - warmup
vpc_access_connector:
  name: "projects/@cloud.application@/locations/@cloud.region@/connectors/@cloud.redis.connector@"
handlers:
  - url: /resources/(.*)$
    static_files: /static/\1
    upload: /static/.*\.(png)$
    require_matching_file: false
automatic_scaling:
...

Static resources are placed inside.jar: BOOT-INF/classes/static

I tried in app.yaml:

- static_files: BOOT-INF/classes/static/\1
- static_files: classes/static/\1

No luck.

Any idea?

Answer 1

This is working for me: (app.yaml)

...

entrypoint: java -noverify -cp "BOOT-INF/resources/:BOOT-INF/classes/:BOOT-INF/lib/*" com.myorg.MySpringBootApp

handlers:
  - url: /(.*\.(gif|png|jpg|svg|ico|css|js|html))$
    static_files: BOOT-INF/classes/static/\1
    upload: BOOT-INF/classes/static/.*\.(gif|png|jpg|svg|ico|css|js|html)$
    secure: always

  - url: /.*
    secure: always
    redirect_http_response_code: 301
    script: auto

...

1. unzip server.jar
2. rm server.jar. This leaves the following folders/files for deployment:

BOOT-INF
META-INF
app.yaml
org

3. gcloud app deploy...

Now you'll see that eg your js-Files have appropriate headers:

...
cache-control: public, max-age=600
content-encoding: gzip
etag: "uh4VxA"
...