Cloud Run: deploying spring docker image causing error; Failed to start and then listen on the port defined by the PORT environment variable

Question

I am trying to deploy spring boot docker image stored at Docker Registry to Cloud Run.
However, when I deployed the image, I got the error;

Cloud Run error: Container failed to start. Failed to start and then listen on the port defined by the PORT environment variable. Logs for this revision might contain more information.

I understand this could be caused by port and address setting, so I fixed these parts referring the official doc, though still experiencing the same error. Concretely, I set these things as below, on application.yml.

server:
  port: ${PORT:8080}
  address: ${ADDRESS:localhost}

I understand PORT variable would be passed by Cloud Run(in my case, port num is set to 8080 on Cloud Run). And also ADDRESS will be passed to by myself(the value is 0.0.0.0, referring the official doc).

For reference, the below is my Dockerfile building spring boot docker image;

# Stage1 - execute build process
FROM openjdk:14-jdk-alpine as build_process
WORKDIR /back_end
COPY . .
RUN ./gradlew build -x test

# Stage2 - boot app with the build output above
FROM openjdk:14-jdk-alpine
EXPOSE ${PORT}
COPY --from=build_process /back_end/build/libs/back_end-0.0.1-SNAPSHOT.jar ./app.jar
RUN adduser -D user
USER user
ENTRYPOINT ["sh","-c","java -jar app.jar"]

Any help would be really appreciated. Thank you so much for reading!

Answer 1

I figured it out why my docker image had failed Cloud Run's health check. After all, it is not about Port and IP address, but about the timing when the health check process executes.
The health check process seems to start immediately once the image is deployed, though my case it took almost 30 secs to launch spring boot tomcat server after deploying to Cloud Run.
That led to the failure of the health check process, so I fixed settings to launch tomcat server immediately too, which solved the issue I posted.