#!/bin/bash

##################################################
# Mount dir                                      #
# - /opt/zk/data                                 #
# - /opt/zk/dataLog                              #
# - /opt/zk/logs                                 #
# ENV                                            #
# - MYID                                         #
# - JVMFLAGS                                     #
# - _CONF_*                                      #
##################################################

set -euo pipefail
export LANG=en_US.UTF-8
trap Quit EXIT

PIDS=
GOT_SIGTERM=

function Print {
    local file=/dev/null
    [ '-f' = "$1" ] && file=$2 && shift && shift
    date +"[%F %T] $*" | tee -a $file
}

function Quit {
    while :; do
        pkill -f java && Print killing java ... || break
        sleep 1
    done
    Print Container stopped.
    test -n "$GOT_SIGTERM"
}

function Usage {
    Print 'This container should run with
    **root user**
    **/opt/zk/{data,dataLog,logs} mounted from host**
    '
}

function ModifyConf {
    Print Modify server.properties ...
    local kv=
    local conf='conf/zoo.cfg'
    while read kv; do
        [ -z "$kv" ] && break
        Print Modify property: ${kv%%=*} ...
        sed -i "/^${kv%%=*} *=/d" $conf
        echo "$kv" >> $conf
    done <<< "$(env | grep '^_CONF_' | sed 's/_CONF_//')"
    sed -i -e '/^dataDir/d' -e '/^dataLogDir/d' $conf
    echo -e 'dataDir=/opt/zk/data\ndataLogDir=/opt/zk/dataLog' >> $conf
    if [ ! -e data/myid ]; then
        Print Generate myid ...
        echo $MYID > data/myid
    fi
}

function StartProc {
    Print Start zookeeper ...
    ./bin/zkServer.sh start-foreground &>> logs/zk.out &
    PIDS="$PIDS $!"
}

function Main {
    local pid=
    cd /opt/zk
    Usage
    ModifyConf
    StartProc
    trap "GOT_SIGTERM=1; Print Got SIGTERM ..." SIGTERM
    while [ -z "$GOT_SIGTERM" ] && sleep 1; do
        for pid in $PIDS; do
            [ ! -e /proc/$pid ] && Print Unexpected error! && exit
        done
    done
}

# Start here
Main