GH-16784 - migrate to chainguard

Author: valenad1

docker/public/Dockerfile-h2o-release

@@ -1,4 +1,4 @@
-FROM registry.access.redhat.com/ubi8/ubi-minimal
+FROM 353750902984.dkr.ecr.us-east-1.amazonaws.com/thirdparty-chainguard-openjdk:v17-dev-latest
 
 ARG H2O_VERSION
 # Mandatory labels required by Red Hat for certification
@@ -9,21 +9,11 @@ LABEL "release"=${H2O_VERSION}
 LABEL "summary"="H2O Open Source Machine Learning platform"
 LABEL "description"="H2O is an Open Source, Distributed, Fast & Scalable Machine Learning Platform: Deep Learning, Gradient Boosting (GBM) & XGBoost, Random Forest, Generalized Linear Modeling (GLM with Elastic Net), K-Means, PCA, Generalized Additive Models (GAM), RuleFit, Support Vector Machine (SVM), Stacked Ensembles, Automatic Machine Learning (AutoML), etc."
 
+# Switch to root to install packages (Chainguard runs as non-root by default)
+USER root
+
 # Install libgomp - to enable XGBoost multithreading
-RUN microdnf install wget tar gzip \
-    && microdnf install libgomp
-RUN microdnf clean all
-
-# Install Java 17 (GraalVM Community Edition 22.2.0)
-RUN wget -O /tmp/graalvm-ce.tar.gz https://github.com/graalvm/graalvm-ce-builds/releases/download/vm-22.2.0/graalvm-ce-java17-linux-amd64-22.2.0.tar.gz \
-    && mkdir /tmp/graalvm/ \
-    && cd /tmp/graalvm/ \
-    && tar xfz /tmp/graalvm-ce.tar.gz \
-    && mkdir /opt/java/ \
-    && cp -r graalvm-ce-* /opt/java/ \
-    && cd /opt/java/graalvm-ce-* \
-    && /bin/bash -c 'for cmd in $(ls bin/); do alternatives --install /usr/bin/$cmd $cmd $PWD/bin/$cmd 1; done' \
-    && rm -r /tmp/graalvm-ce.tar.gz /tmp/graalvm/
+RUN apk add --no-cache libgomp
 
 # Copy H2O-3 artifact into the container
 RUN mkdir -p /opt/h2oai/h2o-3/
@@ -41,4 +31,5 @@ COPY LICENSE /licenses/
 # Overridable by the user
 CMD java -Djava.library.path=/opt/h2oai/h2o-3/xgb_lib_dir -XX:+UseContainerSupport -XX:MaxRAMPercentage=50 -jar /opt/h2oai/h2o-3/h2o.jar
 
-USER 852
+# Switch to nonroot user (Chainguard default: UID 65532)
+USER 65532