On CentOS v7 the PostgreSQL server is started with `systemd`.
Check if `/usr/lib/systemd/system/httpd.service` contains a line `PrivateTmp=true`.
If so then Apache cannot see the `/tmp/.s.PGSQL.5432` file. It's a good security feature,
On CentOS v7 the PostgreSQL server is started with `systemd`.
Check if `/usr/lib/systemd/system/httpd.service` contains a line `PrivateTmp=true`.
If so then Apache cannot see the `/tmp/.s.PGSQL.5432` file. It's a good security feature,