Re: multi-install PostgresNode fails with older postgres versions

On 3/30/21 6:22 PM, Alvaro Herrera wrote:
> On 2021-Mar-30, Mark Dilger wrote:
>
>> Once you have a node running, you can query the version using
>> safe_psql, but that clearly doesn't work soon enough, since we need
>> the information prior to running initdb.
> I was thinking something like examining some file in the install dir --
> say, include/server/pg_config.h, but that seems messier than just
> running pg_config.
>
>> One of the things I noticed while playing with this new toy (thanks,
>> Andrew!)

(I'm really happy someone is playing with it so soon.)

>> is that if you pass a completely insane install_path, you
>> don't get any errors. In fact, you get executables and libraries from
>> whatever PATH="/no/such/postgres:$PATH" gets you, probably the
>> executables and libraries of your latest development branch. By
>> forcing get_new_node to call the pg_config of the path you pass in,
>> you'd fix that problem. I didn't do that, mind you, but you could. I
>> just executed pg_config, which means you'll still get the wrong
>> version owing to the PATH confusion.
> Hmm, I think it should complain if you give it a path that doesn't
> actually contain a valid installation.
>

Yeah, it should be validated. All things considered I think just calling
'pg_config --version' is probably the simplest validation, and likely to
be sufficient.

I'll try to come up with something tomorrow.

cheers

andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com