Re: How to debug: password authentication failed for user

On 2/27/25 10:57, Greg Sabino Mullane wrote:
> On Thu, Feb 27, 2025 at 1:32 PM Tom Lane <tgl@sss.pgh.pa.us 
> <mailto:tgl@sss.pgh.pa.us>> wrote:
> 
>      > -c 'ALTER USER timeshift_user PASSWORD '"'"'timeshift_pass'"'"';'
>      > I am still trying to work out what that quoting is doing?
> 
> 
> That's standard for -x output for some versions of bash. FWIW, none of 
> the shells I had access to output it quite like that, but who knows what 
> shell the OP has. It's basically trying to stop the current ALTER USER 

I have to believe it is is related to this sequence:

docker build -f ./Dockerfile --build-arg PGPASSWORD=timeshift_pass

[...]

ARG PGPASSWORD

ENV POSTGRES_PASSWORD=$PGPASSWORD

[...]

ENV PGUSER=timeshift_user
ENV PGPASSWORD=$PGPASSWORD

[...]

RUN chmod +x ./01-create-database.sh ./04-alter-owner.sh

Where /01-create-database.sh has:

echo "Setting password for $PGUSER to $PGPASSWORD"
psql --username=postgres --dbname=postgres -c "ALTER USER $PGUSER 
PASSWORD '$PGPASSWORD';"

I just don't know enough about Docker to really understand all the hoops 
that are being jumped through in the above.


> statement, add a new single quote (but wrap it in double quotes!), then 
> start a new single-quoted string (the actual password). (So single, 
> double-single-double, single). Then do it all again at the end. It's 
> valid, and it should really be equivalent to PASSWORD 'timeshift_pass' 
> so it's hard to see what the problem is.
> 
> The fact that a manual ALTER ROLE cleared it up certainly suggests that 
> something is going wrong, however, and the SELECT rolpassword output 
> definitely means it had some password. A possibility is that somehow the 
> user password was already set and this particular statement was not run 
> (or run on a different cluster).
> 
> Another debug technique might be to have the shell script write the 
> ALTER USER command to a temp file, then slurp it in via psql -f. Then 
> you can cat that file as part of the script's output
> 
> Cheers,
> Greg
> 
> --
> Crunchy Data - https://www.crunchydata.com <https://www.crunchydata.com>
> Enterprise Postgres Software Products & Tech Support
> 

-- 
Adrian Klaver
adrian.klaver@aklaver.com