From new CentOS 7 install:

Disable selinux:

change /etc/selinux/config to SELINUX=disabled

Add access to PostgreSQL yum repository

Instructions are here: https://yum.postgresql.org/

• From this page, copy the link for CentOS 7 and install:

  $ sudo yum install https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm

Install Postgres 13.2 server (in a container or on the host)

on the host:

$ sudo su -
# yum install postgresql13-server
$ su - postgres
$ /usr/pgsql-13/bin/initdb -A md5 -W #-W forces the user to provide a superuser (postgres) password
$ exit
# systemctl start postgresql-13
# systemctl status postgresql-13

-or- in a container

NOTE: you do not need postgresql13-server if running postgres within a docker container.

Install docker and docker-compose using instructions here:

https://docs.docker.com/engine/installation/linux/centos/

https://docs.docker.com/compose/install/

Install traffic_ops

$ sudo yum install traffic_ops

Install any extensions needed

• install in /opt/traffic_ops_extensions

Install openssl certs (or use this to generate them)

$ sudo /opt/traffic_ops/install/bin/generateCert

as the root user run postinstall

$ sudo su -
# /opt/traffic_ops/install/bin/postinstall