I have a Spring Boot app in Docker that runs on Heroku.
Recently, after updating Tomcat to 10.1.0-M10, I started getting this error:
Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
The immediate thought of downgrading to lower versions doesn't work due to vulnerabilities in the earlier versions. I have checked possible causes and found Tomcat binding port issue.
I cannot set up fixed config for different ports as I am deploying to Heroku and dependent on their random ports.
My Dockerfile:
FROM azul/zulu-openjdk-alpine:11
ENV PORT=$PORT
COPY /target/app.jar /app.jar
CMD java -Xms256m -Xmx512m \
-Dlog4j2.formatMsgNoLookups=true \
-Djava.security.egd=file:/dev/./urandom \
-Dserver.port=$PORT \
-jar /app.jar
What is the way to solve it? Is there anything I am missing?
UPDATE:
There are more logs from Heroku:
Feb 22 12:50:16 integration-test app/web.1 2022-02-22 20:50:16.057 [main] INFO c.g.s.z.ApplicationKt - Started ApplicationKt in 8.09 seconds (JVM running for 9.062)
Feb 22 12:50:16 integration-test app/web.1 2022-02-22 20:50:16.060 [main] DEBUG o.s.b.a.ApplicationAvailabilityBean - Application availability state LivenessState changed to CORRECT
Feb 22 12:50:16 integration-test app/web.1 2022-02-22 20:50:16.063 [main] DEBUG o.s.b.a.ApplicationAvailabilityBean - Application availability state ReadinessState changed to ACCEPTING_TRAFFIC
Feb 22 12:51:06 integration-test heroku/web.1 Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
I found a solution that wasn't perfect but seemed to work for me.
2.6.3 to 2.6.110.X.X to 9.X.XI think the two latest did the magic. Dev tools stopped asking for an extra port in the test/prod environment. Tomcat bound the port in the version 9.X.X but not in 10.X.X.
Even though I found the solution, I don't know why it behaved like this, and it isn't perfect security-wise.
from the error message it seems that $PORT is not resolved to any environment variable.
deploying to heroku you must use .env file to define env vars (you can't use docker run -e PORT=1234) see documentation
When you use heroku locally, you can set config vars in a .env file. When heroku local is run .env is read and each name/value pair is set in the environment. You can use this same .env file when using Docker:
docker run -p 5000:5000 --env-file .env <image-name>