First of all, I'm a CPA who is keen to IT so I apologize for my dumbness regarding this matter.

I have an apache webserver running with postgresql under ubuntu server and suddenly it just stopped to work

My application stopped to work due to postgresql initialisation issues

~$ sudo service postgresql start
* Starting PostgreSQL 9.4 database server * The PostgreSQL server failed to start. Please check the log output:
2015-12-10 10:09:04 BRST [2618-1] FATAL: could not access private key file "/etc/ssl/private/ssl-cert-snakeoil.key": Permission denied

My folder permissions
~$ ls -la /etc/ssl/private
-rwxrwxrwx 1 postgres postgres 1704 Set 4 11:26 ssl-cert-snakeoil.key

I tried to set folder and file permissions to 0755 and few others parameters but nothing changed.

How can I fix this? Should I need to reinstall postgresql?

Thanks in advance, any help will be much appreciated!