#!/bin/sh

set -e
set -o xtrace

cat > "/etc/sysctl.d/10-postgresql-performance.conf" << _EOF_
# See 'http://www.postgresql.org/docs/9.3/static/kernel-resources.html'
# for best practices.
# It is recommended to disable memory overcommit,
# but the Python interpreter may require it on smaller flavors.
# We therefore stick with the heuristic overcommit setting.
vm.overcommit_memory=0

_EOF_

cat > "/etc/rc.local" << _EOF_
# See 'http://www.postgresql.org/docs/9.3/static/kernel-resources.html'
# Disable Linux kernel transparent huge pages. This feature is not supported by
# by Postgres 9.3 and may negatively impact performance of the database.
if test -f /sys/kernel/mm/redhat_transparent_hugepage/defrag; then
  echo never > /sys/kernel/mm/redhat_transparent_hugepage/defrag
fi
if test -f /sys/kernel/mm/redhat_transparent_hugepage/enabled; then
  echo never > /sys/kernel/mm/redhat_transparent_hugepage/enabled
fi

exit \$?

_EOF_

dnf install -y http://yum.postgresql.org/9.4/fedora/fedora-22-x86_64/pgdg-fedora94-9.4-4.noarch.rpm

dnf install -y postgresql94-server postgresql94-contrib postgresql94-devel gcc

###########################################
# Hack alert:
# For Postgresql 9.4, pg_rewind is not in the main source tree and
# no packages exist in the repos, so it must be compiled manually
# and installed on the image until we can move to 9.5
# See README at
# https://github.com/vmware/pg_rewind/tree/REL9_4_STABLE

dev_pkgs="readline-devel zlib-devel krb5-devel openssl-devel pam-devel libxml2-devel libxslt-devel"

yum install -y $dev_pkgs

# We need pg_config to be accessible on the path
mkdir -p /tmp/build
cd /tmp/build
git clone https://github.com/vmware/pg_rewind.git --branch REL9_4_STABLE
git clone https://github.com/postgres/postgres.git --branch REL9_4_STABLE

ln -s /usr/pgsql-9.4/bin/pg_config /usr/bin/pg_config

cd pg_rewind
make USE_PGXS=1 top_srcdir=/tmp/build/postgres install
ln -s /usr/pgsql-9.4/bin/pg_rewind /usr/bin/pg_rewind

# Cleanup

cd
rm -rf /tmp/build
yum remove -y $dev_pkgs


# Though /var/lib/pgsql is the preferred directory, need to move it as
# this is where the volume will be mounted
su - postgres -c "/usr/pgsql-9.4/bin/initdb /var/lib/pgsql/9.4/data"
mv /var/lib/pgsql /var/lib/postgresql

mv /lib/systemd/system/postgresql-9.4.service /lib/systemd/system/postgresql.service

sed -i 's/PGDATA=\/var\/lib\/pgsql\/9.4\/data/PGDATA=\/var\/lib\/postgresql\/9.4\/data/' /lib/systemd/system/postgresql.service

# Create a volatile directory for runtime files.
echo "d /var/run/postgresql/ 0755 postgres postgres" > /lib/tmpfiles.d/postgresql.conf

# Install the native Python client.
dnf install -y postgresql-devel python-devel
pip install psycopg2

systemctl enable postgresql.service
systemctl start postgresql.service