Error: server closed the connection unexpectedly

[def324]

I'm getting the following error when trying to create a snapshot:

Failed to create snapshot
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.

Further on the postgres server it shows the following in the logs:

FATAL:  terminating connection due to administrator command
STATEMENT:  SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity WHERE pg_stat_activity.datname = 'postgres'

I'm running postgres15 in a docker container and using the default "postgres" databse. Here is the docker-compose service in case that is helpful:

  web-postgres-dev:
    image: postgres:15
    restart: always
    ports:
      - "5432:5432"
    environment:
      POSTGRES_PASSWORD: <mypw>
    volumes:
      - postgres-data:/var/lib/postgresql/data

I'm not entirely sure if I'm using DSLR in a way it's not intended to be used or if there is maybe an issue with the version I'm using. I looked through the code of DSLR a bit and I was actually able to make the snapshot part work with a small edit to the code. Please see this commit for my attempt: main...def324:DSLR:closed-connection-patch

However with this "fix" I'm then unable to restore the snapshot, getting the following error:

Failed to restore snapshot
cannot drop the currently open database

This leads me to believe that I'm trying to use DSLR in a way it was not intended to. Could it be that the default "postgres" database is not supported? I'd appreciate any help with this.

[def324]

After some further analysis I figured out that the default postgres db can indeed not be used in the current implementation since it is used to create the connection to the database and it can therefore not be altered. I believe that this is a valid use case, so I propose either one of the following fixes:

• Use the template1 database for the connection. While it was not meant for this purpose, it should exist and be usable for this purpose in regular development environments. (https://github.com/def324/DSLR/tree/fix-postgres-db-v1)
• Use a custom working db named dslr_working_db and create this upon initialization. (https://github.com/def324/DSLR/tree/fix-postgres-db-v2)

I created a pull request for the first approach since I think it's the cleaner way, however the other approach could work too.