Subject: pgpass file in postresql.auto.conf?

From: "Dan Mahoney (Gushi)" <[email-masked]>
Date: Fri, 26 Sep 2025 12:05:58 +0000 (UTC)

Hey folks,

In the interest of automation, I've set up a pgpass file for my 
pg_basebackup between master and standby.  This all works, thusly:

pg_basebackup -d 
'postgres://[email-masked]:5432/foo?sslmode=verify-ca' -F p 
--wal-method=stream -P -R -D /var/db/postgres/data17-test3

However, instead of the password getting baked into the pgsql.auto.conf, 
the reference to the passfile gets put in, instead:

# Do not edit this file manually!
# It will be overwritten by the ALTER SYSTEM command.
primary_conninfo = 'user=repuser passfile=''/var/db/postgres/.pgpass'' 
channel_binding=prefer host=10.1.1.1 port=5432 sslmode=''verify-ca'' 
sslnegotiation=postgres sslcompression=0 sslcertmode=allow sslsni=1 
ssl_min_protocol_version=TLSv1.2 gssencmode=disable krbsrvname=postgres 
gssdelegation=0 target_session_attrs=any load_balance_hosts=disable 
dbname=foo'

But it seems postgres won't actually read the passfile.

Sep 26 12:01:27 hostname postgres[42455]: [7-1] 2025-09-26 12:01:27.658 
UTC [42455] FATAL:  could not connect to the primary server: connection to 
server at "10.1.1.1", port 5432 failed: fe_sendauth: no password supplied

Am I doing something wrong here?

I'm loathe to hand-edit the file, because of that warning there.

Why does pg_basebackup put a reference to a file it it won't read it?

Is there an alter system command that can be used to properly populate the 
password into this file?

-Dan

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From: Ron Johnson <[email-masked]>
Date: Fri, 26 Sep 2025 08:47:48 -0400

> the reference to the passfile gets put in, instead:

It's still early in the morning, so I might still be fuzzy-brained, but are
you asking why the repuser password is not hard-coded
into postresql.auto.conf?

> Am I doing something wrong here?

*When* do you get that message?  And what does "for my
pg_basebackup between master and standby" mean?

> Why does pg_basebackup put a reference to a file it it won't read it?

Because you have a subtle bug in the .pgpass file.  It's case sensitive,
and requires the domain name of that's part of $HOSTNAME.

> Is there an alter system command that can be used to properly populate the

Does the .pgpass file work for "regular" connections?

-- 
Death to <Redacted>, and butter sauce.
Don't boil me, I'm still alive.
<Redacted> lobster!

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From: Laurenz Albe <[email-masked]>
Date: Fri, 26 Sep 2025 16:17:44 +0200

> gssdelegation=0 target_session_attrs=any load_balance_hosts=disable 

That happens when "pg_basebackup" used a password file to connect to
the PostgreSQL server.

> But it seems postgres won't actually read the passfile.

Oh yes, it will, as long as it has permissions 0600, 0400 or 0700 and
belongs to the database server OS user (commonly "postgres").
It must have worked for the "pg_basebackup", so PostgreSQL assumes it
will also work for replication.

> Am I doing something wrong here?

That is hard to say.  You should have run "pg_basebackup" as the
same OS user that starts the standby.

> I'm loathe to hand-edit the file, because of that warning there.

Makes sense, although it is OK as long as you don't mess up the file.

> Is there an alter system command that can be used to properly populate the 

Sure.  If the standby server is up and running (even if it cannot connect
to the primary), you can connect and execute

  ALTER SYSTEM SET primary_conninfo = 'password=''my secret password''';

Yours,
Laurenz Albe