Unix start script doesn't respect JAVA_OPTS when xargs isn't installed

[roomscape]

Expected Behavior

• Given I have a Java application that has been built and packaged using the distribution plugin
• and I build a docker image containing the application along with a minimal OS
• and I set the image's entrypoint to be the Unix start script generated by Gradle
• and I set some configuration in the JAVA_OPTS environment variable
• When I start the container
• Then I expect that my JAVA_OPTS configuration should be included in the command line used to launch the java process

Current Behavior

The Unix startup script uses xargs "to parse quoted args". The minimal OS image I'm using doesn't contain xargs. When I run the startup script, I see a warning:

line 233: xargs: command not found

At this point I expect the script to fail. However, the script continues and the application starts up anyway. JAVA_OPTS is not included in the command line.

Context

I use JAVA_OPTS to set the heap size appropriately for the size of the container I'm deploying. For example, in a 1GB container I might set JAVA_OPTS=-Xmx700m, to allocate 700 megabytes of heap and leave 300 megabytes of headroom. This worked fine under Gradle 6.

After upgrading to Gradle 7, the application doesn't respect JAVA_OPTS and starts up with the default amount of memory, which is 1/4 of the available memory. In my 1GB container, the application starts up with 250MB of heap.

My automated tests didn't catch the issue, because the container still starts up fine and has enough memory to respond to requests. The application only starts to fail when deployed and under load.

If the start script requires xargs, I expect it to fail when xargs is not installed.

Steps to Reproduce

https://github.com/roomscape/gradle-start-script

The linked repository contains a Gradle application and a Dockerfile that reproduces the problem. I reproduced the problem in docker since it's an easy way to create an environment where xargs isn't installed.

When running the docker container with --env JAVA_OPTS="-Dfoo=bar", the application should print out

Application was started with -Dfoo=bar

Instead it prints

/example/bin/example: line 233: xargs: command not found
Application was started with -Dfoo=null

Your Environment

Building with Gradle 7.3.3 on OpenJDK 17
Running in Docker on redhat/ubi8-minimal:8.5-218

[ljacomet]

Thanks for your interest in Gradle.

I agree that the launch script should fail in that case and it should not be too complicated to add that check.

[Kurru]

Apparently this may be very broadly true. I've been seeing the same failure message when running my code which uses openjdk:17-oracle

My full Dockerfile

FROM gradle:7.2-jdk17 AS build
COPY --chown=gradle:gradle . /home/gradle/src
WORKDIR /home/gradle/src/my_server
RUN ./gradlew clean installDist --no-daemon

FROM openjdk:17-oracle
EXPOSE 80
RUN mkdir /app
COPY --from=build /home/gradle/src/my_server/build/install/my_server /app/

ENTRYPOINT ["/app/bin/my-server"]

Edit:
I (eventually) figured out the correct install command for openjdk:17-oracle: RUN microdnf install findutils

Was rather difficult to find the correct package manager for this image, though I am unfamiliar with containers.