Ruby with Jemalloc v2.6.6

This allows to compile ruby v 2.6.6 with jemalloc lib to try to reduce memory consuption or leaks of rails application. Based on Buster

FROM debian:buster-slim

RUN set -eux; \
    apt-get update; \
    apt-get install -y --no-install-recommends \
        bzip2 \
        ca-certificates \
        libffi-dev \
        libgmp-dev \
        libssl-dev \
        libyaml-dev \
        procps \
        zlib1g-dev \
        libjemalloc-dev \
    ; \
    rm -rf /var/lib/apt/lists/*

# skip installing gem documentation
RUN set -eux; \
    mkdir -p /usr/local/etc; \
    { \
        echo 'install: --no-document'; \
        echo 'update: --no-document'; \
    } >> /usr/local/etc/gemrc

ENV RUBY_MAJOR 2.6
ENV RUBY_VERSION 2.6.6
ENV RUBY_DOWNLOAD_SHA256 5db187882b7ac34016cd48d7032e197f07e4968f406b0690e20193b9b424841f

# some of ruby's build scripts are written in ruby
#   we purge system ruby later to make sure our final image uses what we just built
RUN set -eux; \
    \
    savedAptMark="$(apt-mark showmanual)"; \
    apt-get update; \
    apt-get install -y --no-install-recommends \
        autoconf \
        bison \
        dpkg-dev \
        gcc \
        libbz2-dev \
        libgdbm-compat-dev \
        libgdbm-dev \
        libglib2.0-dev \
        libncurses-dev \
        libreadline-dev \
        libxml2-dev \
        libxslt-dev \
        make \
        ruby \
        wget \
        xz-utils \
    ; \
    rm -rf /var/lib/apt/lists/*; \
    \
    wget -O ruby.tar.xz "https://cache.ruby-lang.org/pub/ruby/${RUBY_MAJOR%-rc}/ruby-$RUBY_VERSION.tar.xz"; \
    echo "$RUBY_DOWNLOAD_SHA256 *ruby.tar.xz" | sha256sum --check --strict; \
    \
    mkdir -p /usr/src/ruby; \
    tar -xJf ruby.tar.xz -C /usr/src/ruby --strip-components=1; \
    rm ruby.tar.xz; \
    \
    cd /usr/src/ruby; \
    \
# hack in "ENABLE_PATH_CHECK" disabling to suppress:
#   warning: Insecure world writable dir
    { \
        echo '#define ENABLE_PATH_CHECK 0'; \
        echo; \
        cat file.c; \
    } > file.c.new; \
    mv file.c.new file.c; \
    \
    autoconf; \
    gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)"; \
    ./configure \
        --build="$gnuArch" \
        --with-jemalloc \
        --disable-install-doc \
        --enable-shared \
    ; \
    make -j "$(nproc)"; \
    make install; \
    \
    apt-mark auto '.*' > /dev/null; \
    apt-mark manual $savedAptMark > /dev/null; \
    find /usr/local -type f -executable -not \( -name '*tkinter*' \) -exec ldd '{}' ';' \
        | awk '/=>/ { print $(NF-1) }' \
        | sort -u \
        | xargs -r dpkg-query --search \
        | cut -d: -f1 \
        | sort -u \
        | xargs -r apt-mark manual \
    ; \
    apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
    \
    cd /; \
    rm -r /usr/src/ruby; \
# verify we have no "ruby" packages installed
    ! dpkg -l | grep -i ruby; \
    [ "$(command -v ruby)" = '/usr/local/bin/ruby' ]; \
# rough smoke test
    ruby --version; \
    gem --version; \
    bundle --version

# Sanity check for jemalloc
RUN ruby -r rbconfig -e "abort 'jemalloc not enabled' unless RbConfig::CONFIG['LIBS'].include?('jemalloc') || RbConfig::CONFIG['MAINLIBS'].include?('jemalloc')"

# don't create ".bundle" in all our apps
ENV GEM_HOME /usr/local/bundle
ENV BUNDLE_SILENCE_ROOT_WARNING=1 \
    BUNDLE_APP_CONFIG="$GEM_HOME"
ENV PATH $GEM_HOME/bin:$PATH
# adjust permissions of a few directories for running "gem install" as an arbitrary user
RUN mkdir -p "$GEM_HOME" && chmod 777 "$GEM_HOME"

CMD [ "irb" ]

Just built the image

sudo docker build --tag jruby:2.6.6 -f RubyJemalloc.Dockerfile .

and use FROM in main Dockerfile

FROM jruby:2.6.6

RUN apt-get update -qq && apt-get install --no-install-recommends -y \
    build-essential \
    patch \
    ruby-dev \
    zlib1g-dev \
    liblzma-dev \

...