cluster

#!/bin/bash

IMAGE='effata/local-kafka-cluster'
FILE='docker-compose.yml'
BASE_PORT="9091"
PROJECT_NAME="local"

_cluster_down() {
  docker-compose -f $FILE --project-name $PROJECT_NAME down
}

_cluster_up() {
  CLUSTER_SIZE=$1

  if [[ $(uname) = 'Darwin' ]]; then
    HOST_IP=$(ipconfig getifaddr en0 || ipconfig getifaddr en1)
  else
    INTERFACE=$(route -n | grep '^0.0.0.0' | head -n 1 | awk '{print $NF}')
    HOST_IP=$(ip -4 addr show scope global dev $INTERFACE | grep inet | awk '{print $2}' | awk -F"/" '{print $1}')
  fi

  echo "Host IP used for Kafka Brokers is $HOST_IP"

  cat > $FILE <<-END
version: '2'
networks:
  cluster:
    driver: bridge
services:
  zookeeper:
    image: $IMAGE
    command: zookeeper
    ports:
    - 2181:2181
    networks:
    - cluster
END

  add_broker() {
    id=$1
    port=$((BASE_PORT + id))
  cat >> $FILE <<-END
  kafka_$id:
    image: $IMAGE
    environment:
      kafka_port: $port
      kafka_id: $id
      kafka_ip: $HOST_IP
      kafka_rack: rack$id
    hostname: kafka_$id
    ports:
    - $port:$port
    networks:
    - cluster
    links:
    - zookeeper:zookeeper
END

  }

  COUNTER=1
  while [[  $COUNTER -le $CLUSTER_SIZE ]]; do
     add_broker $COUNTER
     let COUNTER=COUNTER+1 
  done

  docker-compose -f $FILE --project-name $PROJECT_NAME up -d
}

COMMAND=$1

if [[ $COMMAND = 'down' ]]; then
  _cluster_down
elif [[ $COMMAND = 'up' ]]; then
  _cluster_up ${2:-"3"}
else
  cat <<HELP
Usage: ./cluster up CLUSTER_SIZE
OR     ./cluster down

HELP
fi