I’m trying to get Lemmy up and running on an Ubuntu 22.04 host. I’ve followed this guide supplemented by googling.

I can actually get to the front end, but it gives me “There was an error on the server.” When I dig into the logs, I see this:

"thread 'main' panicked at 'Error connecting to postgres://lemmy:<my pg password>@postgres:5432/lemmy: FATAL:  password authentication failed for user \"lemmy\"\n","stream":"stderr","time":"2023-06-26T03:14:17.47460915Z"}

The only thing I can find about this error related to Lemmy is this thread, which indicates that the password was not defined in the docker-compose.yml file prior to starting the containers. I have since redone the configuration three times, each time deleting the volumes folder and double-checking that my postgre password is correct both in docker-compose.yml and lemmy.hjson.

Any ideas what might be the problem? Thank you kindly for any help you can provide!

  • Max-P@lemmy.max-p.meEnglish
    0·
    1 year ago

    You can try setting a different password, maybe it’s got a character in it that messes with things. Or try URL-encoding the password in lemmy.hjson.

    You can also use a PostgreSQL client like the psql command line tool or a full fat DB client like DBeaver and try connecting to it and see if it accepts your password or not.

    Example with just Docker and the PostgreSQL container you’re already running:

    max-p@lemmy-host ~/lemmy % docker exec -it lemmy-postgres-1 /bin/bash
postgres:/# psql -h 172.16.32.5 -U lemmy -W
Password: 
psql (15.3)
Type "help" for help.

lemmy=# \dt
                  List of relations
 Schema |            Name            | Type  | Owner 
--------+----------------------------+-------+-------
 public | __diesel_schema_migrations | table | lemmy
[... more tables ...]

    It’ll at least give you pointers as to where the issue lies: on the database side or lemmy’s side.

    • tkohhh@waveform.socialOPEnglish
      1·
      1 year ago

      Thank you for enlightening me on the -W option in psql. I have successfully logged in using the expected password for lemmy. This points to something with the connection string. According to the error log, the connection string being used is:

      postgres://lemmy:<my percent-encoded password>@postgres:5432/lemmy

      As far as I can tell, the percent encoding is correct. Any ideas how to troubleshoot this further?

      edit: it just occurred to me that my container name is lemmy_postgres_1, not postgres as was entered in my lemmy.hjson file. Let’s see if changing that will work…

      edit2: no, that had no effect. I’m getting the authentication error for user lemmy on both the lemmy container and the postgres container. :(

    • tkohhh@waveform.socialOPEnglish
      1·
      1 year ago

      I learned something interesting in doing some more testing…

      Using the -W option does indeed prompt for a password, but it accepts any value entered at the password prompt. In order to actually authenticate with a password when using psql, you must modify the pg_hba.conf file to use scram-sha-256 as the method for type local.

      When I do this, I am unable to authenticate (both while using my actual password, and also while using a password of “test”.

      And then I figured out the problem.

      In my docker-compose.yml, I had put single quotes around my postgres password, thinking this would be safe per my understanding of this question. However, just to check, I tried logging in to psql using the password 'test'. Sure enough, it worked.

      I found another stack exchange with some different advice on strings in yaml: https://stackoverflow.com/questions/53082932/yaml-docker-compose-spaces-quotes

      So, I tried my password again, without the single quotes… and it worked.

      Perhaps this will help somebody beating their head against the wall in the future.