Bug: Dockerfile-java21. Maven can't find JAVA_HOME

[Furion137]

Description:

We are trying to migrate small SAM application from Dockerfile-java17 to Dockerfile-java21. But on java21 our Jenkins job fails while trying to do "mvn clean install" with the error message "The JAVA_HOME environment variable is not defined correctly,
this environment variable is needed to run this program." We don't have such issues on java17.

In short: could you please check that "/var/lang/bin/java" is runnable in Dockerfile-java21 image? As it is in Dockerfile-java17.

According to my investigations %JAVA_HOME is correctly set to "/var/lang". I suppose that here is the code from maven, given us that error:

if [ -z "$JAVA_HOME" ] ; then
  JAVACMD=`which java`
else
  JAVACMD="$JAVA_HOME/bin/java"
fi

if [ ! -x "$JAVACMD" ] ; then
  echo "The JAVA_HOME environment variable is not defined correctly," >&2
  echo "this environment variable is needed to run this program." >&2
  exit 1
fi

Indeed when I run "test '!' -x /var/lang/bin/java" in Dockerfile-java21 it gives me true, while in Dockerfile-java17 it returns false. So, could you please check that "/var/lang/bin/java" is runnable in Dockerfile-java21 image, as it is in Dockerfile-java17?

Sorry for not providing all the steps-to-reproduce, environment and the rest. I hope that if you confirm that "/var/lang/bin/java" is not runnable in java21 and change it to be so, than the problem will be solved. If it's not the root cause, then I will try to provide you all the details.

[mndeveci]

Hi there,

How are you using this image? You shouldn't be using the Dockerfile-java21 directly, instead you should be using the built images from Public ECR here: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-image-repositories.html

I did a quick test to see if mvn clean install would work for an application and I was able to get it run. Here are the steps;

1. Run build image and drop to its shell docker run -it public.ecr.aws/sam/build-java21 /bin/bash
2. Instantiate a SAM application with Java21. By running sam init and selecting 1 -> 1 -> N -> 7 -> 1 -> 2 -> (enter) -> (enter) -> (enter) -> (enter)
3. Go into the function source code by running cd sam-app/HelloWorldFunction/
4. Run mvn clean install in that folder

With this experiment I was able to run the Maven commands above. Can you try with this image to see if it is going to work for your case?

Thanks!

[Furion137]

Yes, we are using image "public.ecr.aws/sam/build-java21", not the dockerfile directly :-) Hmmm... Let me try it your way...

[Furion137]

That seems to work locally on my machines with MacOs and Docker 20.10.6 and later. But not on our Jenkins "Amazon Linux AI 2018.03" and Docker 18.09.9-ce, build 039a7df. So we switched to a Jenkins machine with a newer OS and Docker and now it works. Thanks for help!