oc run mysql --image=openshift/mysql-55-centos7 --env="MYSQL_ROOT_PASSWORD=yourpassword" --env="MYSQL_USER=wp_user" --env="MYSQL_PASSWORD=wp_pass" --env="MYSQL_DATABASE=wp_db" --port=3306 --expose
oc run wordpress --image=wordpress --env="WORDPRESS_DB_USER=wp_user" --env="WORDPRESS_DB_PASSWORD=wp_pass" --env="WORDPRESS_DB_NAME=wp_db" --env="WORDPRESS_DB_HOST=mysql" --port=80 --expose
modify them after dc creation to add storage to those pods (used the UI) and then create your own route (used the UI).
Per https://github.com/OpenRiskNet/home/tree/master/openshift/recipes/wordpress-mysql-example you mentioned that you need to create a replication controller.
Here's the shortcut.
oc run mysql --image=openshift/mysql-55-centos7 --env="MYSQL_ROOT_PASSWORD=yourpassword" --env="MYSQL_USER=wp_user" --env="MYSQL_PASSWORD=wp_pass" --env="MYSQL_DATABASE=wp_db" --port=3306 --expose
oc run wordpress --image=wordpress --env="WORDPRESS_DB_USER=wp_user" --env="WORDPRESS_DB_PASSWORD=wp_pass" --env="WORDPRESS_DB_NAME=wp_db" --env="WORDPRESS_DB_HOST=mysql" --port=80 --expose
modify them after dc creation to add storage to those pods (used the UI) and then create your own route (used the UI).