#!/bin/sh
set -e

CLICKHOUSE_USER=${CLICKHOUSE_USER=clickhouse}
CLICKHOUSE_GROUP=${CLICKHOUSE_GROUP=${CLICKHOUSE_USER}}
CLICKHOUSE_CONFDIR=${CLICKHOUSE_CONFDIR=/etc/clickhouse-server}
CLICKHOUSE_DATADIR=${CLICKHOUSE_DATADIR=/var/lib/clickhouse}
CLICKHOUSE_LOGDIR=${CLICKHOUSE_LOGDIR=/var/log/clickhouse-server}
CLICKHOUSE_BINDIR=${CLICKHOUSE_BINDIR=/usr/bin}
CLICKHOUSE_GENERIC_PROGRAM=${CLICKHOUSE_GENERIC_PROGRAM=clickhouse}

OS=${OS=`lsb_release -is 2>/dev/null || uname -s ||:`}

test -f /etc/default/clickhouse && . /etc/default/clickhouse

if [ "$1" = configure ]; then
    if [ -x "/bin/systemctl" ] && [ -f /etc/systemd/system/clickhouse-server.service ] && [ -d /run/systemd/system ]; then
        # if old rc.d service present - remove it
        if [ -x "/etc/init.d/clickhouse-server" ]; then
            update-rc.d clickhouse-server remove
            echo "ClickHouse init script has migrated to systemd. Please manually stop old server and restart the service: sudo killall clickhouse-server && sleep 5 && sudo service clickhouse-server restart"
        fi

        /bin/systemctl daemon-reload
        /bin/systemctl enable clickhouse-server
    else
        # If you downgrading to version older than 1.1.54336 run: systemctl disable clickhouse-server
        if [ -x "/etc/init.d/clickhouse-server" ]; then
            if [ "$OS" = "rhel" ] || [ "$OS" = "centos" ] || [ "$OS" = "fedora" ]; then
                echo # TODO
            else
                update-rc.d clickhouse-server defaults 19 19 >/dev/null || exit $?
            fi
        fi
    fi

    # Make sure the administrative user exists
    if ! getent passwd ${CLICKHOUSE_USER} > /dev/null; then
        if [ "$OS" = "rhel" ] || [ "$OS" = "centos" ] || [ "$OS" = "fedora" ]; then
            adduser --system --no-create-home --home /nonexistent \
                --shell /bin/false ${CLICKHOUSE_USER} > /dev/null
        else
            adduser --system --disabled-login --no-create-home --home /nonexistent \
                --shell /bin/false --group --gecos "ClickHouse server" ${CLICKHOUSE_USER} > /dev/null
        fi
    fi

    # if the user was created manually, make sure the group is there as well
    if ! getent group ${CLICKHOUSE_GROUP} > /dev/null; then
        addgroup --system ${CLICKHOUSE_GROUP} > /dev/null
    fi

    # make sure user is in the correct group
    if ! id -Gn ${CLICKHOUSE_USER} | grep -qw ${CLICKHOUSE_USER}; then
        adduser ${CLICKHOUSE_USER} ${CLICKHOUSE_GROUP} > /dev/null
    fi

    # check validity of user and group
    if [ "`id -u ${CLICKHOUSE_USER}`" -eq 0 ]; then
        echo "The ${CLICKHOUSE_USER} system user must not have uid 0 (root).
Please fix this and reinstall this package." >&2
        exit 1
    fi

    if [ "`id -g ${CLICKHOUSE_GROUP}`" -eq 0 ]; then
        echo "The ${CLICKHOUSE_USER} system user must not have root as primary group.
Please fix this and reinstall this package." >&2
        exit 1
    fi


    if [ ! -d ${CLICKHOUSE_DATADIR} ]; then
        mkdir -p ${CLICKHOUSE_DATADIR}
        chown ${CLICKHOUSE_USER}:${CLICKHOUSE_GROUP} ${CLICKHOUSE_DATADIR}
        chmod 700 ${CLICKHOUSE_DATADIR}
    fi

    if [ -d ${CLICKHOUSE_CONFDIR} ]; then
        rm -fv ${CLICKHOUSE_CONFDIR}/*-preprocessed.xml ||:
    fi

    [ -e ${CLICKHOUSE_CONFDIR}/preprocessed ] || ln -s ${CLICKHOUSE_DATADIR}/preprocessed_configs ${CLICKHOUSE_CONFDIR}/preprocessed ||:

    if [ ! -d ${CLICKHOUSE_LOGDIR} ]; then
        mkdir -p ${CLICKHOUSE_LOGDIR}
        chown root:${CLICKHOUSE_GROUP} ${CLICKHOUSE_LOGDIR}
        # Allow everyone to read logs, root and clickhouse to read-write
        chmod 775 ${CLICKHOUSE_LOGDIR}
    fi

    # Set net_admin capabilities to support introspection of "taskstats" performance metrics from the kernel
    #  and ipc_lock capabilities to allow mlock of clickhouse binary.

    # 1. Check that "setcap" tool exists.
    # 2. Check that an arbitrary program with installed capabilities can run.
    # 3. Set the capabilities.

    # The second is important for Docker and systemd-nspawn.
    # When the container has no capabilities,
    #  but the executable file inside the container has capabilities,
    #  then attempt to run this file will end up with a cryptic "Operation not permitted" message.

    TMPFILE=/tmp/test_setcap.sh

    command -v setcap >/dev/null \
        && echo > $TMPFILE && chmod a+x $TMPFILE && $TMPFILE && setcap "cap_net_admin,cap_ipc_lock+ep" $TMPFILE && $TMPFILE && rm $TMPFILE \
        && setcap "cap_net_admin,cap_ipc_lock+ep" "${CLICKHOUSE_BINDIR}/${CLICKHOUSE_GENERIC_PROGRAM}" \
        || echo "Cannot set 'net_admin' or 'ipc_lock' capability for clickhouse binary. This is optional. Taskstats accounting will be disabled. To enable taskstats accounting you may add the required capability later manually."

    # Clean old dynamic compilation results
    if [ -d "${CLICKHOUSE_DATADIR}/build" ]; then
        rm -f ${CLICKHOUSE_DATADIR}/build/*.cpp ${CLICKHOUSE_DATADIR}/build/*.so ||:
    fi
fi