add dockerfile

Dockerfile.openj9

@@ -0,0 +1,40 @@
+FROM ubuntu:24.04 AS build
+
+# partly copied from mkdocker.sh
+# Copyright IBM Corp (Eclipse Public License 2.0)
+RUN apt update \
+ && apt upgrade -y \
+ && apt install -qq -y --no-install-recommends \
+      ant ant-contrib autoconf build-essential ca-certificates cmake cpio curl file g++-13 gcc-13 gdb git \
+      libasound2-dev libcups2-dev libdwarf-dev libelf-dev libexpat1-dev libffi-dev libfontconfig libfontconfig1-dev \
+      libfreetype6-dev libnuma-dev libssl-dev libx11-dev libxext-dev libxrandr-dev libxrender-dev libxt-dev libxtst-dev \
+      make nasm pkg-config python3 python3-dev systemtap-sdt-dev unzip wget xvfb zip zlib1g-dev \
+ && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /build
+RUN mkdir /build/bootjdk /build/dist \
+ && wget --progress=dot:mega -O jdk21.tar.gz \
+      https://api.adoptopenjdk.net/v3/binary/latest/21/ga/linux/x64/jdk/openj9/normal/adoptopenjdk \
+ && tar -xzf jdk21.tar.gz --directory=/build/bootjdk --strip-components=1 \
+ && rm -f jdk21.tar.gz
+
+RUN git clone --single-branch --depth 1 \
+      https://github.com/ibmruntimes/openj9-openjdk-jdk21.git \
+      /build/src
+
+WORKDIR /build/src
+RUN bash get_source.sh
+RUN bash configure --with-boot-jdk=/build/bootjdk --with-mixedrefs=static --with-openssl=system
+RUN make all
+
+RUN mv /build/src/build/linux-x86_64-server-release/images/* /build/dist/
+
+# ------
+
+FROM debian:12-slim AS run
+
+COPY --from=build /build/dist/jdk/ /var/lib/jvm/openj9-jdk21
+RUN ln -s /var/lib/jvm/openj9-jdk21/bin/java /usr/bin/java
+ENV JAVA_HOME=/var/lib/jvm/openj9-jdk21
+
+# ------