Running build as non root user

Hi everyone. New here, was wondering if someone had experience with building images as non root user?

I am building kotlin project, (2 step build) and my goal is now to build it as non root user. Here is what my Dockerfile looks like. Any help would be appreciated:

# Build
FROM openjdk:11-jdk-slim as builder

# Compile application
WORKDIR /root
COPY . .
RUN ./gradlew build

FROM openjdk:11-jre-slim

# Add application
COPY --from=builder /root/build/libs/*.jar ./app.jar

# Set the build version
ARG build_version
ENV BUILD_VERSION=$build_version

COPY docker-entrypoint.sh /
RUN chmod 777 /docker-entrypoint.sh
CMD /docker-entrypoint.sh