Unix domain socket "/var/run/postgresql/.s.PGSQL.5432" missing I try to run an application where its database on postgresql. It won't work and I'm getting the following error whenever I try to interact with the Postgres service:

could not connect to server: Aucun fichier ou dossier de ce type
    Is the server running locally and accepting
    connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432`


I checked if Postgresql service is running 

sudo systemctl status postgresql 


postgresql.service - PostgreSQL RDBMS
   Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor preset: enab
   Active: active (exited) since Thu 2019-04-04 10:28:27 +01; 58min ago
 Main PID: 1212 (code=exited, status=0/SUCCESS)
    Tasks: 0 (limit: 3522)
   CGroup: /system.slice/postgresql.service

avril 04 10:28:27 ubuntu systemd[1]: Starting PostgreSQL RDBMS...
avril 04 10:28:27 ubuntu systemd[1]: Started PostgreSQL RDBMS.


checked the content of the socket unix connection 

ls /var/run/postgresql/


got this empty folder 

brahim@ubuntu:/var/log/postgresql$ ls /var/run/postgresql/
10-main.pg_stat_tmp


checked the content of the data directory 

ls /var/lib/postgresql/10/main/


it contains the following

 base         pg_logical    pg_serial     pg_subtrans  pg_wal
 global       pg_multixact  pg_snapshots  pg_tblspc    pg_xact
 pg_commit_ts  pg_notify     pg_stat      pg_twophase  
 postgresql.auto.conf pg_dynshmem   pg_replslot   pg_stat_tmp   
 PG_VERSION   postmaster.opts


the file postgresql.conf has the following configuration

  # - Connection Settings -
  #listen_addresses = 'localhost'
  port = 5432
  max_connections = 100
  unix_socket_directories = '/var/run/postgresql'


I tried to uncomment the listen_addresses instruction and it didn't work, also I've tried with '*' for all, same thing 

the postgresql file log has 

2019-04-04 12:17:57.765 +01 [942] LOG:  listening on IPv4 address "127.0.0.1", port 5432
2019-04-04 12:17:57.767 +01 [942] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
2019-04-04 12:17:58.190 +01 [971] LOG:  database system was shut down at 2019-04-03 20:19:54 +01
2019-04-04 12:17:58.192 +01 [971] PANIC:  replication checkpoint has wrong magic 1886413116 instead of 307747550
2019-04-04 12:17:59.900 +01 [942] LOG:  startup process (PID 971) was terminated by signal 6: Aborted
2019-04-04 12:17:59.900 +01 [942] LOG:  aborting startup due to startup process failure
2019-04-04 12:17:59.902 +01 [942] LOG:  database system is shut down


I am running postgresql 10.6
any thoughts
Try passing the -a option to ls to also show files starting with the period . character (i.e. "hidden" files):

$ ls -a /var/run/postgresql/
.  ..  .s.PGSQL.5432  .s.PGSQL.5432.lock