FROM ubuntu:12.04.5

# defines root user, to perform privileged operations
USER root

# enable apt mirrors (best performance due to use the closest repository)
RUN readonly APT_SOURCES="/etc/apt/sources.list" \
    && readonly UBUNTU_RELEASE_NAME="$(cat /etc/lsb-release | grep CODENAME | cut -d '=' -f2)" \
    && sed --in-place \
            --regexp-extended \
            --expression \
              "1s/^/deb mirror:\/\/mirrors\.ubuntu\.com\/mirrors\.txt "${UBUNTU_RELEASE_NAME}"-security main restricted universe multiverse\n\n/" \
            --expression \
              "1s/^/deb mirror:\/\/mirrors\.ubuntu\.com\/mirrors\.txt "${UBUNTU_RELEASE_NAME}"-backports main restricted universe multiverse\n/" \
            --expression \
              "1s/^/deb mirror:\/\/mirrors\.ubuntu\.com\/mirrors\.txt "${UBUNTU_RELEASE_NAME}"-updates main restricted universe multiverse\n/" \
            --expression \
              "1s/^/deb mirror:\/\/mirrors\.ubuntu\.com\/mirrors\.txt "${UBUNTU_RELEASE_NAME}" main restricted universe multiverse\n/" \
            --expression \
              "1s/^/\# Enable Ubuntu mirrors and multiverse\n/" \
            "${APT_SOURCES}"

# upgrade Ubuntu packages, install security updates and required packages
RUN readonly UBUNTU_PACKAGES=" \
                curl \
                " \
    && apt-get update \
    && apt-get upgrade --assume-yes \
    && apt-get install --no-install-recommends \
                        --assume-yes \
                        ${UBUNTU_PACKAGES} \
    # remove apt cache in order to improve Docker image size
    && apt-get clean

## Solr
# environment variables
ENV SOLR_VERSION 3.5.0
ENV SOLR_USER solr
ENV SOLR_UID 8983
ENV SOLR_PORT 8983

# declare required packages
RUN readonly SOLR_PACKAGES=" \
              openjdk-6-jre-headless \
              tomcat6 \
              " \
    # install packages
    && apt-get install \
                --no-install-recommends \
                --assume-yes \
                ${SOLR_PACKAGES} \
    # remove apt cache in order to improve Docker image size
    && apt-get clean

# create group
RUN groupadd \
      --system \
      --gid ${SOLR_UID} \
      ${SOLR_USER} \
    # create user and add to group
    && useradd \
        --system \
        --uid ${SOLR_UID} \
        --gid ${SOLR_USER} \
        ${SOLR_USER}

# create temp folder
RUN mkdir /tmp/solr \
    && cd /tmp/solr \
    # download Solr
    && curl \
        --silent \
        --show-error \
        --location \
        --output apache-solr-${SOLR_VERSION}.tgz \
        https://archive.apache.org/dist/lucene/solr/${SOLR_VERSION}/apache-solr-${SOLR_VERSION}.tgz \
    # extract Solr
    && tar \
        --extract \
        --gunzip \
        --file \
          apache-solr-${SOLR_VERSION}.tgz \
        --directory \
          /opt \
    # link Solr folder
    && ln \
        --symbolic \
        --force \
        /opt/apache-solr-${SOLR_VERSION} \
        /opt/solr \
    # change permissions
    && chown \
        --recursive \
        ${SOLR_USER}:${SOLR_USER} \
        /opt/apache-solr-${SOLR_VERSION} \
    && chown \
        --recursive \
        ${SOLR_USER}:${SOLR_USER} \
        /opt/solr \
    # purge source files
    && cd / \
    && rm \
        --recursive \
        --force \
        /tmp/solr

ADD schema.xml /opt/apache-solr-3.5.0/example/solr/conf/schema.xml

## DUMB-init
# more information at: https://github.com/Yelp/dumb-init

# environment variables
ENV DUMB_INIT_VERSION 1.2.0

# download
RUN mkdir \
      --parents \
      /tmp/dumb-init \
    && cd /tmp/dumb-init \
    && curl \
        --silent \
        --show-error \
        --location \
        --remote-name \
        https://github.com/Yelp/dumb-init/releases/download/v${DUMB_INIT_VERSION}/dumb-init_${DUMB_INIT_VERSION}_amd64.deb \
    # install
    && dpkg \
        --install \
        dumb-init_${DUMB_INIT_VERSION}_amd64.deb \
    # remove temp folder
    && cd / \
    && rm \
        --force \
        --recursive \
        /tmp/dumb-init

## Docker specifics
# expose Solr service port
EXPOSE ${SOLR_PORT}

# drop back to the regular Solr user - good practice
USER ${SOLR_USER}

# change workdir to Solr folder
WORKDIR /opt/solr/example

# docker entrypoint/cmd configuration
ENTRYPOINT ["/usr/bin/dumb-init", "--"]
CMD ["java","-Xmx256m","-jar","start.jar"]