Re: ubuntu 18: PostgreSQL does not start. how can I totally remove and reinstall it

Thanks Adrian

On 23.01.21 21:45, Adrian Klaver wrote:
> On 1/23/21 12:36 PM, robert rottermann wrote:
>> Hi there
>>
>> I made somehow a mess with my PostgreSQL installation an an ubuntu 18.4 with
>> PostgreSQL 10.0
>>
>> service postgresql status
>> ● postgresql.service - PostgreSQL RDBMS
>>     Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor
>> preset: enabled)
>>     Active: active (exited) since Sat 2021-01-23 21:21:13 CET; 2min 26s ago
>>    Process: 1853 ExecStart=/bin/true (code=exited, status=0/SUCCESS)
>>   Main PID: 1853 (code=exited, status=0/SUCCESS)
>
> What if you try:
>
> sudo service postgresql(at)10-main status
>
> Also  what does:
>
> pg_lsclusters
>
> show?
root(at)elfero-test:~/scripts# pg_lsclusters
Ver Cluster Port Status Owner    Data directory              Log file
10  main    5433 online postgres /var/lib/postgresql/10/main
/var/log/postgresql/postgresql-10-main.log
root(at)elfero-test:~/scripts# service postgresql(at)10-main status
● postgresql(at)10-main(dot)service - PostgreSQL Cluster 10-main
   Loaded: loaded (/lib/systemd/system/postgresql(at)(dot)service; indirect; vendor
preset: enabled)
   Active: active (running) since Sat 2021-01-23 22:11:40 CET; 9h ago
  Process: 1348 ExecStart=/usr/bin/pg_ctlcluster --skip-systemctl-redirect
10-main start (code=exited, status=0/SUCCESS)
 Main PID: 1460 (postgres)
    Tasks: 7 (limit: 4543)
   CGroup: /system.slice/system-postgresql.slice/postgresql(at)10-main(dot)service
           ├─1460 /usr/lib/postgresql/10/bin/postgres -D
/var/lib/postgresql/10/main -c config_file=/etc/postgresql/10/main/postgresql.conf
           ├─1471 postgres: 10/main: checkpointer process
           ├─1472 postgres: 10/main: writer process
           ├─1473 postgres: 10/main: wal writer process
           ├─1474 postgres: 10/main: autovacuum launcher process
           ├─1475 postgres: 10/main: stats collector process
           └─1476 postgres: 10/main: bgworker: logical replication launcher

Jan 23 22:11:38 elfero-test systemd[1]: Starting PostgreSQL Cluster 10-main...

Jan 23 22:11:40 elfero-test systemd[1]: Started PostgreSQL Cluster 10-main.

Now I can also run psql. (why I could not before, I do not know ..)
BUT still I can not access the db from python.
even a simple python script like:

importpsycopg2
conn = psycopg2.connect(host="localhost", user="postgres", database="postgres")

Produces:

root(at)elfero-test:~/scripts# python test_elfero.py
Traceback (most recent call last):
  File "test_elfero.py", line 2, in <module>
    conn = psycopg2.connect(host="localhost", user="postgres", database="postgres")
  File "/usr/lib/python2.7/dist-packages/psycopg2/__init__.py", line 130, in
connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not connect to server: Connection refused
    Is the server running on host "localhost" (127.0.0.1) and accepting
    TCP/IP connections on port 5432?

Any help is much appreciated

Robert