#! /bin/bash 
if [ "$(whoami)" != "root" ]; then
    SUDO=sudo
fi
${SUDO} apt install -y postgresql pwgen

RAND_PASS=`pwgen -s1 16`
POSTGRES_VERSION=`${SUDO} apt show postgresql | grep Version | cut -d" " -f2 | cut -d"+" -f1`

read -p "Postgres replica ip: " -ei '' REPLICA_IP
read -p "Postgres replica user: " -ei 'replica_user' REPLICA_USER 
read -p "Postgres replica password: " -ei "$RAND_PASS" REPLICA_PASS 
${SUDO} echo $REPLICA_PASS > /usr/local/src/postgres_replica_password
${SUDO} echo "Password is stored in /usr/local/src/postgres_replica_password"

sudo -u postgres pg_conftool set listen_addresses  0.0.0.0
sudo -u postgres pg_conftool set log_destination   syslog
sudo -u postgres pg_conftool set max_wall_senders  3
sudo -u postgres pg_conftool set wal_keep_size     1GB
sudo -u postgres pg_conftool set wal_level         replica
sudo -u postgres pg_conftool set wal_log_hints     on

sudo -u postgres psql -c "CREATE USER '$REPLICA_USER' REPLICATION LOGIN CONNECTION LIMIT 3 ENCRYPTED PASSWORD '$REPLICA_PASS';" 
${SUDO} echo "host    replication     $REPLICA_USER      $REPLICA_IP/24          trust" >> /etc/postgresql/$POSTGRES_VERSION/main/pg_hba.conf

${SUDO} systemctl restart postgresql