#!/bin/bash

command=$1
config=$2
opt=$3

cd "$(dirname "$0")"

docker_min_version='1.2.0'
docker_rec_version='1.2.0'

config_file=containers/"$config".yml
cidfile=cids/"$config".cid
cidbootstrap=cids/"$config"_boostrap.cid
local_discourse=local_discourse
image=samsaffron/discourse:1.0.6
docker_path=`which docker.io || which docker`

if [ "${SUPERVISED}" = "true" ]; then
  restart_policy="--restart=no"
  attach_on_start="-a"
  attach_on_run="-a stdout -a stderr"
else
  attach_on_run="-d"
fi

if [ -x "$(which ip 2>/dev/null)" ]; then
  docker_ip=`ip addr show docker0 | \
                  grep 'inet ' | \
                  awk '{ split($2,a,"/"); print a[1] }';`
else
  docker_ip=`ifconfig | \
                  grep -B1 "inet addr" | \
                  awk '{ if ( $1 == "inet" ) { print $2 } else if ( $2 == "Link" ) { printf "%s:" ,$1 } }' | \
                  grep docker0 | \
                  awk -F: '{ print $3 }';`
fi


usage () {
  echo "Usage: launcher COMMAND CONFIG [--skip-prereqs]"
  echo "Commands:"
  echo "    start:      Start/initialize a container"
  echo "    stop:       Stop a running container"
  echo "    restart:    Restart a container"
  echo "    destroy:    Stop and remove a container"
  echo "    enter:      Use nsenter to enter a container"
  echo "    ssh:        Start a bash shell in a running container"
  echo "    logs:       Docker logs for container"
  echo "    mailtest:   Test the mail settings in a container"
  echo "    bootstrap:  Bootstrap a container for the config based on a template"
  echo "    rebuild:    Rebuild a container (destroy old, bootstrap, start new)"
  echo
  echo "Options:"
  echo "    --skip-prereqs   Don't check prerequisites"
  exit 1
}

compare_version() {
    declare -a ver_a
    declare -a ver_b
    IFS=. read -a ver_a <<< "$1"
    IFS=. read -a ver_b <<< "$2"

    while [[ -n $ver_a ]]; do
        if (( ver_a > ver_b )); then
            return 0
        elif (( ver_b > ver_a )); then
            return 1
        else
            unset ver_a[0]
            ver_a=("${ver_a[@]}")
            unset ver_b[0]
            ver_b=("${ver_b[@]}")
        fi
    done
    return 1  # They are equal
}

prereqs() {

  # 1. docker daemon running?
  test=`$docker_path info >/dev/null`

  if [[ $? -ne 0 ]] ; then
    echo "Cannot connect to the docker daemon - verify it is running and you have access"
    exit 1
  fi

  # 2. running aufs or btrfs
  test=`$docker_path info 2> /dev/null | grep 'Driver: '`
  if [[ "$test" =~ [aufs|btrfs] ]] ; then : ; else
    echo "Your Docker installation is not using the recommended AuFS (union filesystem) and may be unstable."
    echo "If you are unable to bootstrap / stop your image please report the issue at:"
    echo "https://meta.discourse.org/t/discourse-docker-installation-without-aufs/15639"
  fi

  # 3. running recommended docker version
  test=($($docker_path --version))  # Get docker version string
  test=${test[2]//,/}  # Get version alone and strip comma if exists

  [[ "$test" =~ "0.12.0" ]] && echo "You are running a broken version of Docker, please upgrade ASAP. See: https://meta.discourse.org/t/the-installation-stopped-in-the-middle/16311/ for more details." && exit 1

  # At least minimum version
  if compare_version "${docker_min_version}" "${test}"; then
    echo "ERROR: Docker version ${test} not supported, please upgrade to at least ${docker_min_version}, or recommended ${docker_rec_version}"
    exit 1
  fi

  # Recommend best version
  if compare_version "${docker_rec_version}" "${test}"; then
    echo "WARNING: Docker version ${test} deprecated, recommend upgrade to ${docker_rec_version} or newer."
  fi

  # 4. able to attach stderr / out / tty
  test=`$docker_path run -i --rm -a stdout -a stderr $image echo working`
  if [[ "$test" =~ "working" ]] ; then : ; else
    echo "Your Docker installation is not working correctly"
    echo
    echo "See: https://meta.discourse.org/t/docker-error-on-bootstrap/13657/18?u=sam"
    exit 1
  fi
}

if [ "$opt" != "--skip-prereqs" ] ; then
  prereqs
fi

get_ssh_pub_key() {
  local ${ssh_key_locations}
  ssh_key_locations=(
    ~/.ssh/id_ed25519.pub
    ~/.ssh/id_ecdsa.pub
    ~/.ssh/id_rsa.pub
    ~/.ssh/id_dsa.pub
    ~core/.ssh/authorized_keys
  )

  local $keyfile
  for keyfile in "${ssh_key_locations[@]}"; do
    if [[ -e ${keyfile} ]] ; then
      ssh_pub_key="$(cat ${keyfile})"
      return 0
    fi
  done

  if tty -s ; then
    echo "This user has no SSH key, but a SSH key is required to access the Discourse Docker container."
    read -p "Generate a SSH key? (Y/n) " -n 1 -r
    if [[ $REPLY =~ ^[Nn]$ ]] ; then
      echo
      echo WARNING: You may not be able to log in to your container.
      echo
    else
      echo
      echo Generating SSH key
      mkdir -p ~/.ssh && ssh-keygen -f ~/.ssh/id_rsa -t rsa -N ''
      echo
      ssh_pub_key="$(cat ~/.ssh/id_rsa.pub)"
      return 0
    fi
  fi

  return 1
}


install_docker() {

  echo "Docker is not installed, make sure you are running on the 3.8 kernel"
  echo "The best supported Docker release is Ubuntu 12.04.03 for it run the following"
  echo
  echo "sudo apt-get update"
  echo "sudo apt-get install linux-image-generic-lts-raring linux-headers-generic-lts-raring"
  echo "sudo reboot"
  echo

  echo "sudo sh -c \"wget -qO- https://get.docker.io/gpg | apt-key add -\""
  echo "sudo sh -c \"echo deb http://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list\""
  echo "sudo apt-get update"
  echo "sudo apt-get install lxc-docker"

  exit 1
}

host_run() {
  read -r -d '' env_ruby << 'RUBY'
  require 'yaml'

  input = STDIN.readlines.join
  yaml = YAML.load(input)

  if host_run = yaml['host_run']
    params = yaml['params'] || {}
    host_run.each do |run|
      params.each do |k,v|
        run = run.gsub("$#{k}", v)
      end
      STDOUT.write "#{run}--SEP--"
    end
  end
RUBY

  host_run=`cat $config_file | $docker_path run --rm -i -a stdout -a stdin $image ruby -e "$env_ruby"`

  while [ "$host_run" ] ; do
    iter=${host_run%%--SEP--*}
    echo
    echo "Host run: $iter"
    $iter || exit 1
    echo
    host_run="${host_run#*--SEP--}"
  done
}


set_volumes() {
  volumes=`cat $config_file | $docker_path run --rm -i -a stdout -a stdin $image ruby -e \
        "require 'yaml'; puts YAML.load(STDIN.readlines.join)['volumes'].map{|v| '-v ' << v['volume']['host'] << ':' << v['volume']['guest'] << ' '}.join"`
}

set_links() {
    links=`cat $config_file | $docker_path run --rm -i -a stdout -a stdin $image ruby -e \
        "require 'yaml'; puts YAML.load(STDIN.readlines.join)['links'].map{|l| '--link ' << l['link']['name'] << ':' << l['link']['alias'] << ' '}.join"`
}

set_template_info() {

    templates=`cat $config_file | $docker_path run --rm -i -a stdin -a stdout $image ruby -e \
      "require 'yaml'; puts YAML.load(STDIN.readlines.join)['templates']"`


    arrTemplates=(${templates// / })
    config_data=$(cat $config_file)

    input="hack: true"


    for template in "${arrTemplates[@]}"
    do
      [ ! -z $template ] && {
        input="$input _FILE_SEPERATOR_ $(cat $template)"
      }
    done

    # we always want our config file last so it takes priority
    input="$input _FILE_SEPERATOR_ $config_data"

    read -r -d '' env_ruby << 'RUBY'
    require 'yaml'

    input=STDIN.readlines.join
    # default to UTF-8 for the dbs sake
    env = {'LANG' => 'en_US.UTF-8'}
    input.split('_FILE_SEPERATOR_').each do |yml|
       yml.strip!
       begin
         env.merge!(YAML.load(yml)['env'] || {})
       rescue Psych::SyntaxError => e
        puts e
        puts "*ERROR."
       rescue => e
        puts yml
        p e
       end
    end
    puts env.map{|k,v| "-e\n#{k}=#{v}" }.join("\n")
RUBY

    raw=`exec echo "$input" | $docker_path run --rm -i -a stdin -a stdout $image ruby -e "$env_ruby"`

    env=()
    ok=1
    while read i; do
      if [ "$i" == "*ERROR." ]; then
        ok=0
      elif [ -n "$i" ]; then
        env[${#env[@]}]=$i
      fi
    done <<< "$raw"

    if [ "$ok" -ne 1 ]; then
      echo "${env[@]}"
      echo "YAML syntax error. Please check your /var/docker/containers/*.yml config files."
      exit 1
    fi
    echo "Calculated ENV: ${env[@]}"
}

[ -z $docker_path ] && {
  install_docker
}


[ $# -lt 2 ] && {
  usage
}

if [ ! -e $config_file ]
  then
    echo "Config file was not found, ensure $config_file exists"
    echo ""
    echo "Available configs ( `cd containers && ls -dm *.yml | tr -s '\n' ' ' | awk '{ gsub(/\.yml/, ""); print }'`)"
    exit 1
fi


docker_version=($($docker_path --version))
docker_version=${test[2]//,/}

if compare_version "1.2.0" "$docker_version"; then
  echo "We recommend you upgrade docker, the version you are running has no restart policies, on reboot your container may not start up"
  restart_policy=""
else
  restart_policy=${restart_policy:---restart=always}
fi


run_mailtest(){
  if [ ! -e $config_file ]; then
    echo "Config does not exist: $config_file" >&2
    exit 1
  fi
  exec scripts/mailtest $config_file
}

run_stop(){
  if [ ! -e $cidfile ]
     then
       echo "No cid found"
       exit 1
     else
       $docker_path stop -t 10 `cat $cidfile`
  fi
}

run_start(){

  host_run

  if [ ! -e $cidfile ]
     then
       echo "No cid found, creating a new container"
       ports=`cat $config_file | $docker_path run --rm -i -a stdout -a stdin $image ruby -e \
              "require 'yaml'; puts YAML.load(STDIN.readlines.join)['expose'].map{|p| '-p ' << p.to_s << ' '}.join"`

       set_template_info
       set_volumes
       set_links

       existing=`$docker_path ps -a | awk '{ print $1, $(NF) }' | grep "$config$" | awk '{ print $1 }'`
       if [ ! -z $existing ]
       then
         echo "Found an existing container by its name, recovering cidfile, please rerun"
         echo $existing > $cidfile
         exit 1
       fi

       $docker_path run $links $attach_on_run $restart_policy "${env[@]}" -h "`hostname`-$config" -e DOCKER_HOST_IP=$docker_ip --name $config -t --cidfile $cidfile $ports \
                  $volumes $local_discourse/$config /sbin/boot

       exit 0
     else
       cid=`cat $cidfile`

       if [ -z $cid ]
       then
         echo "Detected empty cid file, deleting, please re-run"
         rm $cidfile
         exit 1
       fi

       found=`$docker_path ps -q -a --no-trunc | grep $cid`
       if [ -z $found ]
       then
         echo "Invalid cid file, deleting, please re-run"
         rm $cidfile
         exit 1
       fi

       echo "cid found, ensuring container is started"
       $docker_path start $attach_on_start `cat $cidfile`
       exit 0
  fi

}

run_bootstrap(){

  host_run

  get_ssh_pub_key

  # Is the image available?
  # If not, pull it here so the user is aware what's happening.
  $docker_path history $image >/dev/null 2>&1 || $docker_path pull $image

  set_template_info

  base_image=`cat $config_file | $docker_path run --rm -i -a stdin -a stdout $image ruby -e \
    "require 'yaml'; puts YAML.load(STDIN.readlines.join)['base_image']"`

  update_pups=`cat $config_file | $docker_path run --rm -i -a stdin -a stdout $image ruby -e \
    "require 'yaml'; puts YAML.load(STDIN.readlines.join)['update_pups']"`

  if [[ ! X"" = X"$base_image" ]]; then
    image=$base_image
  fi

  set_volumes
  set_links

  rm -f $cidbootstrap

  run_command="cd /pups &&"
  if [[ ! "false" =  $update_pups ]]; then
    run_command="$run_command git pull &&"
  fi
  run_command="$run_command /pups/bin/pups --stdin"

  echo $run_command

  env=("${env[@]}" "-e" "SSH_PUB_KEY=$ssh_pub_key")

  (exec echo "$input" | $docker_path run $links "${env[@]}" -e DOCKER_HOST_IP=$docker_ip --cidfile $cidbootstrap -i -a stdin -a stdout -a stderr $volumes $image \
     /bin/bash -c "$run_command") \
     || ($docker_path rm `cat $cidbootstrap` && rm $cidbootstrap)

  [ ! -e $cidbootstrap ] && echo "FAILED TO BOOTSTRAP" && exit 1

  sleep 5

  $docker_path commit `cat $cidbootstrap` $local_discourse/$config || echo 'FAILED TO COMMIT'
  $docker_path rm `cat $cidbootstrap` && rm $cidbootstrap
}

case "$command" in
  bootstrap)
      run_bootstrap
      echo "Successfully bootstrapped, to startup use ./launcher start $config"
      exit 0
      ;;

  mailtest)
      run_mailtest
      exit 0
      ;;

  enter)

      if [ ! -e $cidfile ]
         then
           echo "No cid found"
           exit 1
      fi

      if [ ! $UID -eq 0 ] ;
        then
        echo "enter command must run as root, will attempt to sudo"
        echo
      fi

      if [ ! -e bin/nsenter ]
        then
          echo "Downloading nsenter"
          $docker_path pull samsaffron/nsenter
          ($docker_path run --rm samsaffron/nsenter cat /nsenter > bin/nsenter1) || exit 1
          cp bin/nsenter1 bin/nsenter
          chmod +x bin/nsenter
      fi

      PID=$($docker_path inspect --format {{.State.Pid}} `cat $cidfile`)
      SHELL=/bin/bash sudo -E bin/nsenter --target $PID --mount --uts --ipc --net --pid

      exit 0;
      ;;

  ssh)
      if [ ! -e $cidfile ]
         then
           echo "No cid found"
           exit 1
         else
           cid="`cat $cidfile`"
           address="`$docker_path port $cid 22`"
           split=(${address//:/ })
           exec ssh -o StrictHostKeyChecking=no root@${split[0]} -p ${split[1]}
      fi
      ;;

  stop)
      run_stop
      exit 0
      ;;

  logs)

      if [ ! -e $cidfile ]
         then
           echo "No cid found"
           exit 1
         else
           $docker_path logs `cat $cidfile`
           exit 0
      fi
      ;;

  restart)
      run_stop
      run_start
      exit 0
      ;;

  start)
      run_start
      exit 0
      ;;

  rebuild)
      if [ "$(git symbolic-ref --short HEAD)" == "master" ]; then
        echo "Updating discourse docker"
        git pull || (echo 'failed to update' && exit 1)
      fi
      if [ -e $cidfile ]
        then
          echo "Stopping old container"
          $docker_path stop -t 10 `cat $cidfile`
      fi

      run_bootstrap

      if [ -e $cidfile ]
        then
          $docker_path rm `cat $cidfile` && rm $cidfile
      fi

      run_start
      exit 0
      ;;


  destroy)
      if [ -e $cidfile ]
        then
          echo "destroying container $cidfile"
          $docker_path stop -t 10 `cat $cidfile`
          $docker_path rm `cat $cidfile` && rm $cidfile
          exit 0
        else
          echo "nothing to destroy cidfile does not exist"
          exit 1
      fi
      ;;
esac

usage