Can I stop postgres running in the background?

On Kubuntu 20.04

Before I can successfully start a docker container on my computer I need to kill a Postgres process. I do this by:

1. sudo ss -lptn 'sport = :5432'

,which outputs: State Recv-Q Send-Q Local Address:Port Peer Address:Port Process LISTEN 0 244 127.0.0.1:5432 0.0.0.0:* users:(("postgres",pid=1003,fd=5))

2. kill <pid>

Now I would be able to run the docker container that has a Postgres database. I'd like it so that I don't have to follow those steps before I can run any Postgres database. For some reason lsof -i :5432 does not return the process.

Is it standard behaviour for Postgres to be running in the background? Is it safe to stop this process? If yes, how can I stop this process from running automatically in the background?

I have tried the following commands with no success:
sudo systemctl disable postgresql
sudo update-rc.d postgresql disable

Killing a database process is a really good way of destroying a database. PostgreSQL is not installed by default so something or someone must have put it on the machine for a reason. You will want to confirm if anything on your system needs it.

To answer the question, though, you can safely stop PostgreSQL like this:

sudo service postgresql stop

You can prevent PostgreSQL from starting at boot like this:

sudo service postgresql disable

If nothing on your system needs the database engine to be installed locally, you can remove it:

sudo apt --purge remove postgresql

^{Note: This removes just the server element, leaving the client libraries intact to connect to PostgreSQL installations.}