install_postgresql.sh

#!/bin/bash

# The MIT License (MIT)
#
# Copyright (c) 2015 Microsoft Azure
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
#
# Author: Full Scale 180 Inc.

# You must be root to run this script
if [ "${UID}" -ne 0 ];
then
    log "Script executed without root permissions"
    echo "You must be root to run this program." >&2
    exit 3
fi

#Format the data disk
bash vm-disk-utils-0.1.sh -s

# TEMP FIX - Re-evaluate and remove when possible
# This is an interim fix for hostname resolution in current VM (If it does not exist add it)
grep -q "${HOSTNAME}" /etc/hosts
if [ $? == 0 ];
then
  echo "${HOSTNAME}found in /etc/hosts"
else
  echo "${HOSTNAME} not found in /etc/hosts"
  # Append it to the hsots file if not there
  echo "127.0.0.1 ${HOSTNAME}" >> /etc/hosts
fi

# Get today's date into YYYYMMDD format
now=$(date +"%Y%m%d")

# Get passed in parameters $1, $2, $3, $4, and others...
MASTERIP=""
SUBNETADDRESS=""
NODETYPE=""
REPLICATORPASSWORD=""
PGHEALTHPASSWORD=""
TRIGGER_USER="trigger"
TRIGGER_USER_PASS=""
PG_DATADIR="/var/lib/kafkadir/main"
PG_DATADIR_TRIGGER="/var/lib/kafkadir/trigger"

#Loop through options passed
while getopts :m:s:t:p: optname; do
    log "Option $optname set with value ${OPTARG}"
  case $optname in
    m)
      MASTERIP=${OPTARG}
      ;;
  	s) #Data storage subnet space
      SUBNETADDRESS=${OPTARG}
      ;;
    t) #Type of node (MASTER/SLAVE)
      NODETYPE=${OPTARG}
      ;;
    p) #Replication Password
      REPLICATORPASSWORD=${OPTARG}
      TRIGGER_USER_PASS=${OPTARG}
      ;;
    h)  #show help
      help
      exit 2
      ;;
    \?) #unrecognized option - show help
      echo -e \\n"Option -${BOLD}$OPTARG${NORM} not allowed."
      help
      exit 2
      ;;
  esac
done

export PGPASSWORD=$REPLICATORPASSWORD

logger "NOW=$now MASTERIP=$MASTERIP SUBNETADDRESS=$SUBNETADDRESS NODETYPE=$NODETYPE"

install_postgresql_service() {
	logger "Start installing PostgreSQL..."
	# Re-synchronize the package index files from their sources. An update should always be performed before an upgrade.
	apt-get -y update

	# Install PostgreSQL if it is not yet installed
	if [ $(dpkg-query -W -f='${Status}' postgresql 2>/dev/null | grep -c "ok installed") -eq 0 ];
	then
	  apt-get -y install postgresql=9.3* postgresql-contrib=9.3* postgresql-client=9.3*
	fi

	logger "Done installing PostgreSQL..."
}

setup_datadisks() {

	MOUNTPOINT="/datadisks/disk1"

	# Move database files to the striped disk
	if [ -L /var/lib/kafkadir ];
	then
		logger "Symbolic link from /var/lib/kafkadir already exists"
		echo "Symbolic link from /var/lib/kafkadir already exists"
	else
		logger "Moving  data to the $MOUNTPOINT/kafkadir"
		echo "Moving PostgreSQL data to the $MOUNTPOINT/kafkadir"
		service postgresql stop
		mkdir $MOUNTPOINT/kafkadir
		mv -f /var/lib/kafkadir $MOUNTPOINT/kafkadir

		# Create symbolic link so that configuration files continue to use the default folders
		logger "Create symbolic link from /var/lib/kafkadir to $MOUNTPOINT/kafkadir"
		ln -s $MOUNTPOINT/kafkadir /var/lib/kafkadir
	fi
}

configure_streaming_replication() {
	logger "Starting configuring PostgreSQL streaming replication..."

	# Configure the MASTER node
	if [ "$NODETYPE" == "MASTER" ];
	then
		logger "Create user replicator..."
		echo "CREATE USER replicator WITH REPLICATION PASSWORD '$PGPASSWORD';"
		sudo -u postgres psql -c "CREATE USER replicator WITH REPLICATION PASSWORD '$PGPASSWORD';"


    ### added - allow the health check user to just connect to postgres - for pgpool
    logger "Create user health user..."
    echo "CREATE ROLE mhealthuser WITH LOGIN PASSWORD '$PGHEALTHPASSWORD';"
    sudo -u postgres psql -c "CREATE ROLE mhealthuser WITH LOGIN PASSWORD '$PGHEALTHPASSWORD';"

    logger "Allow health user to connect..."
    echo "GRANT CONNECT ON DATABASE postgres TO mhealthuser;"
    sudo -u postgres psql -c "GRANT CONNECT ON DATABASE postgres TO mhealthuser;"
    ###/added

		### added - move the data file to the new mount point
		sudo mv /var/lib/postgresql/9.3/main /var/lib/kafkadir      ### added
	fi

	# Stop service
	service postgresql stop

	# Update configuration files
	cd /etc/postgresql/9.3/main

	if grep -Fxq "# install_postgresql.sh" pg_hba.conf
	then
		logger "Already in pg_hba.conf"
		echo "Already in pg_hba.conf"
	else
		# Allow access from other servers in the same subnet for replication and health checks
		echo "" >> pg_hba.conf
		echo "# install_postgresql.sh" >> pg_hba.conf
		echo "host replication replicator $SUBNETADDRESS md5" >> pg_hba.conf
		echo "hostssl replication replicator $SUBNETADDRESS md5" >> pg_hba.conf
		echo "host postgres mhealthuser $SUBNETADDRESS trust" >> pg_hba.conf
		echo "hostssl postgres mhealthuser $SUBNETADDRESS trust" >> pg_hba.conf

		# allow remote acccess in this subnet
		echo "host all all $SUBNETADDRESS md5" >> pg_hba.conf
		echo "hostssl all all $SUBNETADDRESS md5" >> pg_hba.conf

		echo "" >> pg_hba.conf

		logger "Updated pg_hba.conf"
		echo "Updated pg_hba.conf"
	fi

	if grep -Fxq "# install_postgresql.sh" postgresql.conf
	then
		logger "Already in postgresql.conf"
		echo "Already in postgresql.conf"
	else

		# Change configuration including both master and slave configuration settings
		echo "" >> postgresql.conf
		echo "# install_postgresql.sh" >> postgresql.conf
		echo "listen_addresses = '*'" >> postgresql.conf
		echo "wal_level = hot_standby" >> postgresql.conf
		echo "max_wal_senders = 10" >> postgresql.conf
		echo "wal_keep_segments = 500" >> postgresql.conf
		echo "checkpoint_segments = 8" >> postgresql.conf
		echo "archive_mode = on" >> postgresql.conf
		echo "archive_command = 'cd .'" >> postgresql.conf
		echo "hot_standby = on" >> postgresql.conf

		# point to the new data directory
		echo "data_directory='/var/lib/kafkadir/main'" >> postgresql.conf ### added
		echo "" >> postgresql.conf

		logger "Updated postgresql.conf"
		echo "Updated postgresql.conf"
	fi

	# Synchronize the slave
	if [ "$NODETYPE" == "SLAVE" ];
	then

	  sudo -u postgres mkdir /var/lib/kafkadir/main   ### added
	  sudo chown -R postgres:postgres /var/lib/kafkadir/      ### added

		# Remove all files from the slave data directory
		logger "Remove all files from the slave data directory"
		sudo -u postgres rm -rf /var/lib/kafkadir/main

		# Make a binary copy of the database cluster files while making sure the system is put in and out of backup mode automatically
		logger "Make binary copy of the data directory from master"
		sudo PGPASSWORD=$PGPASSWORD -u postgres pg_basebackup -h $MASTERIP -D /var/lib/kafkadir/main -U replicator -x

		# Create recovery file
		logger "Create recovery.conf file"

		sudo -i  ### added
		cd /var/lib/kafkadir/main/

		sudo -u postgres echo "standby_mode = 'on'" > recovery.conf
		sudo -u postgres echo "primary_conninfo = 'host=$MASTERIP port=5432 user=replicator password=$PGPASSWORD'" >> recovery.conf
		#sudo -u postgres echo "trigger_file = '/var/lib/kafkadir/main/failover'" >> recovery.conf
		sudo -u postgres echo "trigger_file = '/var/lib/kafkadir/trigger/trigger_file'" >> recovery.conf

		sudo chown postgres:postgres recovery.conf #added to make sure recovery is under the postgres account
	fi

	logger "Done configuring PostgreSQL streaming replication"
}

# The trigger user is an O/S level user that can be used to trigger failover from a remote machine
create_trigger_user() {
  logger "In create_trigger_user"
  if [[ -n ${TRIGGER_USER} ]]; then
        logger "create_trigger_user TRIGGER_USER is not empty - continuing"

        # create the trigger user if he does not exist
        ret=false
        getent passwd ${TRIGGER_USER} >/dev/null 2>&1 && ret=true
        if ! $ret; then
          logger "Creating trigger user: ${TRIGGER_USER}"
          echo "Creating trigger user: ${TRIGGER_USER}"
          useradd ${TRIGGER_USER}
          echo "${TRIGGER_USER}:${TRIGGER_USER_PASS}" | chpasswd
          mkdir /home/${TRIGGER_USER}
          chown ${TRIGGER_USER}:${TRIGGER_USER} /home/${TRIGGER_USER}
        fi

        # create trigger folder
        logger "Creating trigger folder"
        mkdir -p ${PG_DATADIR_TRIGGER}
        chmod -R 0777 ${PG_DATADIR_TRIGGER} #allows anyone

        #turn on password auth
        logger "Enabling password auth"
        sed -i -re 's/^(\#?)(PasswordAuthentication)([[:space:]]+)no/\2\3yes/' /etc/ssh/sshd_config
        sed -i -re 's/^(\#)(PasswordAuthentication)([[:space:]]+)(.*)/\2\3\4/' /etc/ssh/sshd_config

        #add the trigger user
        logger "Adding the trigger user"
        echo "" >> /etc/ssh/sshd_config
        echo "# install_postgresql.sh" >> /etc/ssh/sshd_config
        echo AllowUsers trigger >> /etc/ssh/sshd_config
        echo "" >> /etc/ssh/sshd_config

        #restart the service
        logger "Start SSH Service"
        service ssh restart
  fi
}

# MAIN ROUTINE
install_postgresql_service

setup_datadisks

service postgresql start

create_trigger_user

configure_streaming_replication

service postgresql start

# added - to do the replication we need the master restarted - not sure why [yet] but perhaps to do with the data drive remapping above
if [ "$NODETYPE" == "MASTER" ];
then
  #sleep 60
  service postgresql stop ### added - kick the server to pick up data folder changes
  service postgresql start
fi