interview_task.sh

#!/bin/bash

# Make sure only root can run our script
if [ "$(id -u)" != "0" ]; then
   echo 'This script must be run as root!' 1>&2
   exit 1
fi

# Add needed repositories 
if ! add-apt-repository -y ppa:openjdk-r/ppa; then
  echo 'Could not add openjdk ppa repo.Aborting!'
  exit 1
fi

if ! echo "deb http://www.apache.org/dist/cassandra/debian 36x main" > /etc/apt/sources.list.d/cassandra.sources.list; then
  echo "Could not add cassandra repo. Aborting!"
  exit 1
fi

# Import cassandra gpg keys
if ! curl https://www.apache.org/dist/cassandra/KEYS | apt-key add - ; then
  echo 'Could not add cassandra keys. Aborting!'
  exit 1
fi

# Update apt cache
apt-get update

# Install openjdk java 8 
if ! apt-get install -y openjdk-8-jdk; then
  echo 'Could not install java. Aborting!'
  exit 1
fi

# Install cassandra
if ! apt-get install -y cassandra; then
  echo 'Could not install cassandra. Aborting!'
  exit 1
fi

# Download latest kairosdb from github
if ! wget --quiet https://github.com/kairosdb/kairosdb/releases/download/v1.1.2/kairosdb_1.1.2-1_all.deb -O /tmp/kairosdb_1.1.2-1_all.deb; then
  echo 'Could not download kairosdb. Aborting!'
  exit 1
fi

# Install kairosdb
if ! dpkg --install /tmp/kairosdb_1.1.2-1_all.deb; then
  echo 'Could not install kairosdb. Aborting!'
  exit 1
fi

# This is used for starting rpc_server in cassandra so kairosdb could talk to it
sed 's/start_rpc:\ false/start_rpc:\ true/' -i /etc/cassandra/cassandra.yaml 

# This is used for changing the datastore for kairosdb
sed 's/^kairosdb.service.datastore=org.kairosdb.datastore.h2.H2Module$/^kairosdb.service.datastore=org.kairosdb.datastore.cassandra.CassandraModule$/' -i /opt/kairosdb/conf/kairosdb.properties

# Start cassandra
if ! service cassandra start && sleep 4; then 
  echo "Cassandra didn't start correctly!"
  exit 1
fi

# Start kairosdb
if ! service kairosdb start; then
  echo "Kairosdb didn't start correctly!"
  exit 1
fi

exit 0