HOWTO? Permissions for user to access a single db
Hi,
Amateur question here :-{ Despite using Postgres for 15 years it's always
been locked safely inside a VPS with Hibernate on top powering a Java web
app. Each customer is on a separate VPS which typically has ~500k rows over
about 30 tables. Basic but very effective.
We now need to provide access to an associate company to a single database
(3 tables, ~10k rows) that our java app writes to (not JDBC, via
Hibernate). We have a nice SSH tunnel coming in, but they cannot view the
shared database (yes, I'm an amateur).
I'm just looking for beginners suggestions to get this db visible to this
user so we can continue our trials. They have their own Linux user login,
and their SSH access gives them access to port 5432 and nothing else. They
can see postgres, but no databases are visible.
Ubuntu 22.04
PG14
Their Linux user (say): "user2" / "theuser2linuxpwd"
Postgres user (say): "user2" / "myuser2pwd"
Postgres db they access (say): "mytransferdb"
In psql I did:
create user user2 with encrypted password 'myuser2pwd';
grant all privileges on database mytransferdb to user2;
I didn't think it was a pg_hba.conf issue because via SSH tunnel
they appear inside linux as if localhost (I think?).
After you stop laughing/crying, can anyone guide me?
Huge thx
-Damian
Re: HOWTO? Permissions for user to access a single db
Hi Tom, Sorry for the kinda-complicated response. We have worked for years with this other product (let's call it PP), and maybe 20% of our customers are in common, traditionally both products sitting on the same windows PC in some office accessing localhost PG. No problem. All data belongs to the customer and security is a customer issue. PP only has a windows desktop product. We also have a web solution served from Linux VPS (one VPS per customer), and any single customer is on one VPS/IP which only has a single PG installation/instance on it. 100% default PG setup. No tweaking at all. 100% isolation from everything. The PP product is still running on the windows PC in the customer office, so we give them an SSH tunnel to get into our VPS at 5432. The PP product is on MSSQL, so they use some connector (sorry, no idea what) from the customer PC to access my PG14 on Ubuntu. In our first trial/proof-of-concept we gave them PG superuser access. They could see everything in PG, including the bits they need. Working, but too open for my liking. This is their screenshot supplied to me of a working connection [image: image.png] Below is our second trial/proof-of-concept where I tried to limit them to ONLY need-to-know on the one shared database they read from. It seems they are accessing (the one and only) PG cluster on the VPS, but no database is visible, only "default". [image: image.png] Apologies for the vagaries. I assumed this is just a pg user permissions issue. Maybe not. -Damian On Tue, 14 Feb 2023 at 08:59, Tom Lane wrote: > Damian Carey writes: > > We now need to provide access to an associate company to a single > database > > (3 tables, ~10k rows) that our java app writes to (not JDBC, via > > Hibernate). We have a nice SSH tunnel coming in, but they cannot view the > > shared database (yes, I'm an amateur). > > > I'm just looking for beginners suggestions to get this db visible to this > > user so we can continue our trials. They have their own Linux user login, > > and their SSH access gives them access to port 5432 and nothing else. > They > > can see postgres, but no databases are visible. > > What do you mean by "visible" ... that "select * from pg_database" > shows only "postgres"? If so, the most likely theory is that they > are not connecting to the same Postgres instance you are. > There's not any permission-based filtering on what you can see in > that catalog. > > regards, tom lane >
Re: HOWTO? Permissions for user to access a single db
Thx Tom Fine advice that I will follow up. One tiny thing without wasting (too much) more of your time. In the working "promiscuous" version they get access the VPS as the same linux user that my product is running on, and superuser PG access. In the failed version their SSH login is as a different and very limited linux user, as well as their own postgres user name. Still on a "permissions" theme ... is their any glaring issues that are required to provide a random linux user with permissions to access a DB? (FYI every few years you graciously help me like this and I'm well aware of our skill difference and the vague questions I regurgitate. Kudos.) Thx -Damian On Tue, 14 Feb 2023 at 09:54, Tom Lane wrote: > Damian Carey writes: > > The PP product is on MSSQL, so they use some connector (sorry, no idea > > what) from the customer PC to access my PG14 on Ubuntu. > > Black boxes are fun aren't they. > > > This is their screenshot supplied to me of a working connection > > [image: image.png] > > Below is our second trial/proof-of-concept where I tried to limit them to > > ONLY need-to-know on the one shared database they read from. > > It seems they are accessing (the one and only) PG cluster on the VPS, but > > no database is visible, only "default". > > [image: image.png] > > These images didn't come through, but they probably wouldn't have > added anything anyway. > > It seems that either their connector is doing something strange or > you misconfigured things on your side, but there's no evidence here > to say which. I'd counsel enabling log_connections, and maybe > log_statements too, and then looking into the postmaster log to see > what happens when they try to connect. > > regards, tom lane >
Re: HOWTO? Permissions for user to access a single db
Tom, Rob & Adrian,
I understand exactly what each of you are getting at, but instead of
fumbling and further wasting your time I'm going to get a freelancer to
smash out a suitable setup sans beginner mistakes. It's a pretty basic
problem for a learned colleague.
I've clearly thrived in my safely walled PG garden for too long to sort
this basic stuff. Our Linux consultant is top notch, but PG's not his core
skill.
Appreciate you all taking the time. Wish I could have asked a more
satisfying question with a neat and useful solution :-)
Huge thx.
-Damian
On Tue, 14 Feb 2023 at 10:58, Adrian Klaver
wrote:
> On 2/13/23 13:45, Damian Carey wrote:
> > Hi,
> >
> > Amateur question here :-{ Despite using Postgres for 15 years it's
> > always been locked safely inside a VPS with Hibernate on top powering a
> > Java web app. Each customer is on a separate VPS which typically has
> > ~500k rows over about 30 tables. Basic but very effective.
> >
> > We now need to provide access to an associate company to a single
> > database (3 tables, ~10k rows) that our java app writes to (not JDBC,
> > via Hibernate). We have a nice SSH tunnel coming in, but they cannot
> > view the shared database (yes, I'm an amateur).
> >
> > I'm just looking for beginners suggestions to get this db visible to
> > this user so we can continue our trials. They have their own Linux user
> > login, and their SSH access gives them access to port 5432 and nothing
> > else. They can see postgres, but no databases are visible.
>
> Define in detail what "... databases are visible" means?
>
> In psql does \l show anything?
>
>
> >
> > Ubuntu 22.04
> > PG14
> > Their Linux user (say): "user2" / "theuser2linuxpwd"
> > Postgres user (say): "user2" / "myuser2pwd"
> > Postgres db they access (say): "mytransferdb"
> >
> > In psql I did:
> > create user user2 with encrypted password 'myuser2pwd';
> > grant all privileges on database mytransferdb to user2;
>
> The above GRANT is not doing what you probably think it is doing.
>
> From
>
> https://www.postgresql.org/docs/current/ddl-priv.html
>
> "all privileges on database: means:
>
> CREATE
>
> For databases, allows new schemas and publications to be created
> within the database, and allows trusted extensions to be installed
> within the database.
>
> CONNECT
>
> Allows the grantee to connect to the database. This privilege is
> checked at connection startup (in addition to checking any restrictions
> imposed by pg_hba.conf).
>
> >
> > I didn't think it was a pg_hba.conf issue because via SSH tunnel
> > they appear inside linux as if localhost (I think?).
> >
> > After you stop laughing/crying, can anyone guide me?
> >
> > Huge thx
> > -Damian
>
> --
> Adrian Klaver
> adrian.kla...@aklaver.com
>
>
