Add Alpine 3.20 image for linux-riscv64

Author: adamretter

alpine3_riscv64/Dockerfile

@@ -0,0 +1,72 @@
+FROM riscv64/alpine:3.20
+
+LABEL org.opencontainers.image.authors="Evolved Binary Ltd <tech@evolvedbinary.com>"
+
+LABEL name="Alpine 3 (riscv64) RocksJava Build Environment" \
+  vendor="Evolved Binary Ltd"
+
+# make: Allow N jobs at once; infinite jobs with no arg
+ARG JOBS=1
+
+# version of gflags to compile
+ARG GFLAGS_VERSION=2.2.2
+
+# update Alpine with latest versions
+RUN \
+  apk update \
+  && apk upgrade
+
+# install CA certificates
+RUN apk add ca-certificates
+
+# install build tools
+RUN apk add \
+  build-base \
+  coreutils \
+  file \
+  git \
+  perl \
+  automake \
+  autoconf \
+  cmake
+
+# install tool dependencies for building RocksDB static library
+RUN apk add \
+  curl \
+  bash \
+  wget \
+  tar \
+  openssl
+
+# install RocksDB dependencies
+RUN apk add \
+  snappy snappy-dev \
+  zlib zlib-dev \
+  bzip2 bzip2-dev \
+  lz4 lz4-dev \
+  zstd zstd-dev \
+  linux-headers
+
+# install OpenJDK21
+RUN apk add \
+  openjdk21 \
+  java-cacerts
+
+# cleanup
+RUN rm -rf /var/cache/apk/*
+
+# gflags from source
+RUN \
+  wget -O gflags-$GFLAGS_VERSION.tar.gz https://github.com/gflags/gflags/archive/refs/tags/v$GFLAGS_VERSION.tar.gz \
+  && tar zxvf gflags-$GFLAGS_VERSION.tar.gz \
+  && mkdir gflags-$GFLAGS_VERSION/build \
+  && cd gflags-$GFLAGS_VERSION/build \
+  && CMAKE_INSTALL_PREFIX=/usr cmake .. \
+  && make -j $JOBS \
+  && make install \
+  && cd / \
+  && rm -rf gflags-$GFLAGS_VERSION*
+
+# puts javac in the PATH
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
+ENV PATH=/usr/lib/jvm/java-21-openjdk/bin:$PATH