Instalar Postgres 11 no AMI LINUX 2

Olá, eu tenho uma instancia na AWS, com AMI Linux 2 e não consigo instalar o PostgreSQL 11.

Estou fazendo assim:

yum install https://download.postgresql.org/pub/repos/yum/reporpms/EL-6-x86_64/pgdg-redhat-repo-latest.noarch.rp...

Ele da o erro:

Error: Package: pgdg-redhat-repo-42.0-4.noarch (/pgdg-redhat-repo-latest.noarch)
Requires: /etc/redhat-release
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest

Eu uso esse script:

#!/bin/bash
###############################################
# To use:
# https://raw.github.com/gist/2776351/???
# chmod 777 install_postgresql.sh
# ./install_postgresql.sh
###############################################
echo "*****************************************"
echo " Instalando o PostgreSQL"
echo "*****************************************"
sudo yum -y install postgresql postgresql-server postgresql-devel postgresql-contrib postgresql-docs
sudo service postgresql initdb
# Use MD5 Authentication
sudo sed -i.bak -e 's/ident$/md5/' -e 's/peer$/md5/' /var/lib/pgsql9/data/pg_hba.conf
#start
sudo /sbin/chkconfig --levels 235 postgresql on
sudo service postgresql start

# http://imperialwicket.com/aws-install-postgresql-on-amazon-linux-quick-and-dirty