Dockerfile

FROM openjdk:8-jre-slim

ENV ZOO_CONF_DIR=/conf \
    ZOO_DATA_DIR=/data \
    ZOO_DATA_LOG_DIR=/datalog \
    ZOO_LOG_DIR=/logs \
    ZOO_TICK_TIME=2000 \
    ZOO_INIT_LIMIT=5 \
    ZOO_SYNC_LIMIT=2 \
    ZOO_AUTOPURGE_PURGEINTERVAL=0 \
    ZOO_AUTOPURGE_SNAPRETAINCOUNT=3 \
    ZOO_MAX_CLIENT_CNXNS=60

# Add a user with an explicit UID/GID and create necessary directories
RUN set -eux; \
    groupadd -r zookeeper --gid=1000; \
    useradd -r -g zookeeper --uid=1000 zookeeper; \
    mkdir -p "$ZOO_DATA_LOG_DIR" "$ZOO_DATA_DIR" "$ZOO_CONF_DIR" "$ZOO_LOG_DIR"; \
    chown zookeeper:zookeeper "$ZOO_DATA_LOG_DIR" "$ZOO_DATA_DIR" "$ZOO_CONF_DIR" "$ZOO_LOG_DIR"

# Install required packges
RUN set -eux; \
    apt-get update; \
    DEBIAN_FRONTEND=noninteractive \
    apt-get install -y --no-install-recommends \
        ca-certificates \
        dirmngr \
        gosu \
        gnupg \
        netcat \
        wget; \
    rm -rf /var/lib/apt/lists/*; \
# Verify that gosu binary works
    gosu nobody true

ARG GPG_KEY=3F7A1D16FA4217B1DC75E1C9FFE35B7F15DFA1BA
ARG DISTRO_NAME=zookeeper-3.4.14

# Download Apache Zookeeper, verify its PGP signature, untar and clean up
RUN set -eux; \
    wget -q "https://www.apache.org/dist/zookeeper/$DISTRO_NAME/$DISTRO_NAME.tar.gz"; \
    wget -q "https://www.apache.org/dist/zookeeper/$DISTRO_NAME/$DISTRO_NAME.tar.gz.asc"; \
    export GNUPGHOME="$(mktemp -d)"; \
    gpg --keyserver ha.pool.sks-keyservers.net --recv-key "$GPG_KEY" || \
    gpg --keyserver pgp.mit.edu --recv-keys "$GPG_KEY" || \
    gpg --keyserver keyserver.pgp.com --recv-keys "$GPG_KEY"; \
    gpg --batch --verify "$DISTRO_NAME.tar.gz.asc" "$DISTRO_NAME.tar.gz"; \
    tar -xzf "$DISTRO_NAME.tar.gz"; \
    mv "$DISTRO_NAME/conf/"* "$ZOO_CONF_DIR"; \
    rm -rf "$GNUPGHOME" "$DISTRO_NAME.tar.gz" "$DISTRO_NAME.tar.gz.asc"; \
    chown -R zookeeper:zookeeper "/$DISTRO_NAME"

WORKDIR $DISTRO_NAME
VOLUME ["$ZOO_DATA_DIR", "$ZOO_DATA_LOG_DIR", "$ZOO_LOG_DIR"]

EXPOSE 2181 2888 3888

ENV PATH=$PATH:/$DISTRO_NAME/bin \
    ZOOCFGDIR=$ZOO_CONF_DIR

COPY docker-entrypoint.sh /
RUN chmod +x /docker-entrypoint.sh
ENTRYPOINT ["/docker-entrypoint.sh"]
CMD ["zkServer.sh", "start-foreground"]