Date: Sat, 2 Sep 2023 15:27:57 +0200 (CEST)
From: Erik Wienhold <ewie@ewie.name>
To: Daulat <daulat.dba@gmail.com>,
	pgsql-admin <pgsql-admin@lists.postgresql.org>
Message-ID: <1504262683.74455.1693661277706@office.mailbox.org>
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 <CALfOM6LjKQ4+YTo7eWivnfDny9iRCOvwTij4kQda6qJ=zWgLRw@mail.gmail.com>
References: 
 <CALfOM6LjKQ4+YTo7eWivnfDny9iRCOvwTij4kQda6qJ=zWgLRw@mail.gmail.com>
Subject: Re: DBLINK Error
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On 02/09/2023 09:50 CEST Daulat <daulat.dba@gmail.com> wrote:

> I am facing an issue while fetching data using dblink.
> I am using a .pgpass file and MD5 for authentication.

What does ~postgres/.pgpass and pg_hba.conf look like?

> .pgpass file is located in the home directory (postgres user home) of the
> user running the PostgreSQL query. This file has proper permission 0600 a=
nd
> owner=C2=A0postgres to keep it secure. The OS is Amazon Linux.
>
> Connection made successfully without giving password.
>
> [root@DEM-MT bin]# ./psql -d postgres -U postgres
> psql (14.6)
> Type "help" for help.
>
> postgres=3D#

Does root also have a .pgpass file?  Otherwise this looks like user postgre=
s is
configured with trust authentication (at least on database postgres) if the=
re's
no password prompt for user postgres.

> cd /opt/PostgreSQL-14/bin/
> [root@DEM-MT bin]# ./psql -d postgres -U postgres -W
> Password:
> psql (14.6)
> Type "help" for help.
>
> postgres=3D#

Does it accept any password?  That would be the case for trust authenticati=
on.

> ERROR:
> -----------
>
> cd /opt/PostgreSQL-14/bin/
> [postgres@DMM-MT bin]$ ./psql -U postgres -d tn2_demo_10
>
> tn2_demo_10=3D# select * from ucf.dblink_connect_u('conn','dbname=3D"ADT_=
DEM_DB"');
> ERROR: could not establish connection
> DETAIL: connection to server on socket "/tmp/.s.PGSQL.5432" failed: fe_se=
ndauth: no password supplied

Okay, no trust authentication for user postgres on database ADT_DEM_DB.  My
guess is an error in ~postgres/.pgpass so that libpq does not find a matchi=
ng
entry for the connection.

--
Erik