Postgresql Failed in Ubuntu environment. with error message - "socket "/var/run/postgresql/.s.PGSQL.5432"? - postgresql

Question

One day, My Postgresql server stopped working. Checked log. It was shutdown somehow.
root#ip_address:/# tail /var/log/postgresql/postgresql-10-main.log
2020-02-19 06:47:49.215 CET [23497] LOG: received smart shutdown request
2020-02-19 06:47:49.477 CET [23497] LOG: worker process: logical replication launcher (PID 23512) exited with exit code 1
2020-02-19 06:47:49.482 CET [23507] LOG: shutting down
2020-02-19 06:47:49.546 CET [23497] LOG: database system is shut down
When I run,
root#ip_address:/# psql
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?
It complained that there are no files and directory. so I checked if my postgresql running.
root#ip_address:/# systemctl status postgresql
● postgresql.service - PostgreSQL RDBMS
Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor preset: enabled)
Active: active (exited) since Sun 2020-03-08 16:19:24 CET; 26min ago
Process: 30136 ExecStart=/bin/true (code=exited, status=0/SUCCESS)
Main PID: 30136 (code=exited, status=0/SUCCESS)
Mar 08 16:19:24 vps584959 systemd[1]: Starting PostgreSQL RDBMS...
Mar 08 16:19:24 vps584959 systemd[1]: Started PostgreSQL RDBMS.
It was running. but, if I check postgresql cluster.
root#ip_address:/# pg_lsclusters
Ver Cluster Port Status Owner Data directory Log file
10 main 5432 down postgres /var/lib/postgresql/10/main /var/log/postgresql/postgresql-10-main.log
It was DOWN
so I tried
root#ip_address:/# pg_ctlcluster 10 main start
Error: Config owner (deploy:1003) and data owner (postgres:114) do not match, and config owner is not root
I wasn't able to make it work. then I tried.
sudo chown -R deploy:postgres /var/lib/postgresql/10/ && sudo chmod -R u=rwX,go= /var/lib/postgresql/10/
try again.
root#ip_address:/# pg_ctlcluster 10 main start
Job for postgresql#10-main.service failed because the service did not take the steps required by its unit configuration.
See "systemctl status postgresql#10-main.service" and "journalctl -xe" for details.
root#ip_address:/# systemctl status postgresql#10-main.service
● postgresql#10-main.service - PostgreSQL Cluster 10-main
Loaded: loaded (/lib/systemd/system/postgresql#.service; indirect; vendor preset: enabled)
Active: failed (Result: protocol) since Sun 2020-03-08 16:59:53 CET; 2min 52s ago
Process: 31635 ExecStart=/usr/bin/pg_ctlcluster --skip-systemctl-redirect 10-main start (code=exited, status=1/FAILURE)
Main PID: 23497 (code=exited, status=0/SUCCESS)
Mar 08 16:59:53 vps584959 systemd[1]: Starting PostgreSQL Cluster 10-main...
Mar 08 16:59:53 vps584959 postgresql#10-main[31635]: Error: /usr/lib/postgresql/10/bin/pg_ctl /usr/lib/postgresql/10/bin/pg_ctl start -D /var/lib/postgresql/10/main -l /var/log/postgre
Mar 08 16:59:53 vps584959 systemd[1]: postgresql#10-main.service: Can't open PID file /var/run/postgresql/10-main.pid (yet?) after start: No such file or directory
Mar 08 16:59:53 vps584959 systemd[1]: postgresql#10-main.service: Failed with result 'protocol'.
Mar 08 16:59:53 vps584959 systemd[1]: Failed to start PostgreSQL Cluster 10-main.
Don't know what to do more. Is anybody had the same problem?
More infos.
root#ip_address:/var/run/postgresql# ls
total 0
drwxrwsr-x 3 postgres postgres 60 Feb 19 06:47 .
drwxr-xr-x 28 root root 1060 Mar 8 13:58 ..
drwxr-s--- 2 postgres postgres 40 Feb 19 06:47 10-main.pg_stat_tmp

Answer 1

pg_ctlcluster 10 main start
Error: Config owner (deploy:1003) and data owner (postgres:114) do not match, and config owner is not root
That's pretty clear, isn't it?
The Ubuntu PostgreSQL startup script wants that postgresql.conf and/or pg_hba.conf be owned by user postgres, else it refuses to proceed.