[SPARK-28938][K8S][2.4] Move to supported OpenJDK docker image for Kubernetes

resource-managers/kubernetes/docker/src/main/dockerfiles/spark/Dockerfile

@@ -15,7 +15,7 @@
 # limitations under the License.
 #
 
-FROM openjdk:8-alpine
+FROM openjdk:8-jdk-slim
 
 ARG spark_jars=jars
 ARG img_path=kubernetes/dockerfiles
@@ -29,16 +29,17 @@ ARG k8s_tests=kubernetes/tests
 # docker build -t spark:latest -f kubernetes/dockerfiles/spark/Dockerfile .
 
 RUN set -ex && \
-    apk upgrade --no-cache && \
+    apt-get update && \
     ln -s /lib /lib64 && \
-    apk add --no-cache bash tini libc6-compat linux-pam nss && \
+    apt install -y bash tini libc6 libpam-modules libnss3 && \
     mkdir -p /opt/spark && \
     mkdir -p /opt/spark/work-dir && \
     touch /opt/spark/RELEASE && \
     rm /bin/sh && \
     ln -sv /bin/bash /bin/sh && \
     echo "auth required pam_wheel.so use_uid" >> /etc/pam.d/su && \
-    chgrp root /etc/passwd && chmod ug+rw /etc/passwd
+    chgrp root /etc/passwd && chmod ug+rw /etc/passwd && \
+    rm -rf /var/cache/apt/*
 
 COPY ${spark_jars} /opt/spark/jars
 COPY bin /opt/spark/bin

resource-managers/kubernetes/docker/src/main/dockerfiles/spark/bindings/R/Dockerfile

@@ -20,7 +20,7 @@ FROM $base_img
 WORKDIR /
 RUN mkdir ${SPARK_HOME}/R
 
-RUN apk add --no-cache R R-dev
+RUN apt install -y r-base r-base-dev && rm -rf /var/cache/apt/*
 
 COPY R ${SPARK_HOME}/R
 ENV R_HOME /usr/lib/R

resource-managers/kubernetes/docker/src/main/dockerfiles/spark/bindings/python/Dockerfile

@@ -20,17 +20,15 @@ FROM $base_img
 WORKDIR /
 RUN mkdir ${SPARK_HOME}/python
 # TODO: Investigate running both pip and pip3 via virtualenvs
-RUN apk add --no-cache python && \
-    apk add --no-cache python3 && \
-    python -m ensurepip && \
-    python3 -m ensurepip && \
+RUN apt install -y python python-pip && \
+    apt install -y python3 python3-pip && \
     # We remove ensurepip since it adds no functionality since pip is
     # installed on the image and it just takes up 1.6MB on the image
     rm -r /usr/lib/python*/ensurepip && \
     pip install --upgrade pip setuptools && \
     # You may install with python3 packages by using pip3.6
     # Removed the .cache to save space
-    rm -r /root/.cache
+    rm -r /root/.cache && rm -rf /var/cache/apt/*
 
 COPY python/lib ${SPARK_HOME}/python/lib
 ENV PYTHONPATH ${SPARK_HOME}/python/lib/pyspark.zip:${SPARK_HOME}/python/lib/py4j-*.zip

resource-managers/kubernetes/docker/src/main/dockerfiles/spark/entrypoint.sh

@@ -130,4 +130,4 @@ case "$SPARK_K8S_CMD" in
 esac
 
 # Execute the container CMD under tini for better hygiene
-exec /sbin/tini -s -- "${CMD[@]}"
+exec /usr/bin/tini -s -- "${CMD[@]}"