Nevertheless I had some issues with configuration files and decided to uninstall it completely sudo apt purge postgresql postgresql-contrib pgadmin3
When I installed it again I notice that postgresql.conf and pg_hba.conf were the oldies files. Then I uninstall Postgres once more and removed the directory /etc/postgresql/
After a new install I noticed that the directory /etc/postgresql/ was completely empty - it was not created again. There are no more postgresql.conf and pg_hba.conf files. I could find only postgresql.conf.sample and pg_hba.conf.sample at /usr/share/postgresql/10
/etc/init.d/postgresql status says that Postgres is running fine
● postgresql.service - PostgreSQL RDBMS Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor preset: enabled) Active: active (exited) since Tue 2018-05-08 10:43:23 -03; 1h 55min ago Process: 6451 ExecStart=/bin/true (code=exited, status=0/SUCCESS) Main PID: 6451 (code=exited, status=0/SUCCESS)
What should I have to do to heve the folder /etc/postgresql/10/ ... and all its files agais?