Re: [PATCH] pg_autovacuum commandline password hiding.

Tom Lane wrote:
> psql, pg_dump, etc allow password specification from stdin and from
> .pgpass, never on the command line. There is a reason why they are all
> designed like that. pg_autovacuum hasn't been studied carefully enough
> I guess, because we should never have let a security hole like this get
> by us.

It has certainly been observed that this is a security problem in the
past. In fact, the pg_autovacuum documentation makes that clear:

-P password: Password pg_autovacuum will use to connect with. *WARNING*
This option is insecure. When installed as a Windows Service, this
option will be stored in plain text in the registry. When used with
most Unix variants, other users will be able to see the argument to
the "-P" option via ps(1). The ~/.pgpass file can be used to
specify a password more securely.

I think the reason there is at least some value in having this switch
for pg_autovacuum is that pg_autovacuum is almost exclusively used in a
situation in which the password can't be specified on the command-line
(which is not the case for most of the other command-line tools). Sure,
it isn't secure, but the documentation makes that clear, and security is
not important to everyone -- I can certainly envision users for whom the
command-line flag is convenient.

-Neil