Fixing my connection a Docker postgres after moving to Apple silicon - docker

Question

I have a local project early in development which uses Nestjs and TypeORM to connect to a Docker postgres instance (called 'my_database_server'). Things were working on my old computer, an older Macbook Pro.
I've just migrated everything onto a new Macbook Pro with the new M2 chip (Apple silicon). I've downloaded the version of Docker Desktop that's appropriate for Apple silicon. It runs fine, it still shows 'my_database_server', it can launch that fine, and I can even use the Terminal to go into its Postgres db and see the data that existed in my old computer.
But, I can't figure out how to adjust the config of my project to get it to connect to this database. I've read from other articles that because Docker is running on Apple silicon now and is using emulation, that the host should be different.
This is what my .env used to look like:
POSTGRES_HOST=127.0.0.1
POSTGRES_PORT=5432
POSTGRES_USER=postgres
On my new computer, the above doesn't connect. I have tried these other values for POSTGRES_HOST, many inspired by other SO posts, but these all yield Error: getaddrinfo ENOTFOUND _____ errors:
my_database_server (the container name)
docker (since I didn't use a docker-compose.yaml file - see below - I don't know what the 'service name' is in this case)
192.168.65.0/24 (the "Docker subnet" value in Docker Desktop > Preferences > Resources > Network)
Next, for some other values I tried, the code is trying to connect for a longer time, but it's getting stuck on something later in the process. With these, eventually I get Error: connect ETIMEDOUT ______:
192.168.65.0
172.17.0.2 (from another SO post, I tried the terminal command docker inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' 78f6e532b324 - the last part being the container ID of my_database_server)
In case it helps, I originally set up this docker container using the script I found here, not using a docker-compose.yaml file. Namely, I ran this script once at the beginning:
#!/bin/bash
set -e
SERVER="my_database_server";
PW="mysecretpassword";
DB="my_database";
echo "echo stop & remove old docker [$SERVER] and starting new fresh instance of [$SERVER]"
(docker kill $SERVER || :) && \
(docker rm $SERVER || :) && \
docker run --name $SERVER -e POSTGRES_PASSWORD=$PW \
-e PGPASSWORD=$PW \
-p 5432:5432 \
-d postgres
# wait for pg to start
echo "sleep wait for pg-server [$SERVER] to start";
SLEEP 3;
# create the db
echo "CREATE DATABASE $DB ENCODING 'UTF-8';" | docker exec -i $SERVER psql -U postgres
echo "\l" | docker exec -i $SERVER psql -U postgres
What should be my new db config settings?

Answer 1

I never figured the above problem out, but it was blocking me so I found a different away around.
Per other SO questions, I decided to go with the more typical route of using a docker-compose.yml file to create the Docker container. In case it helps others in this problem, this is what the main part of my docker-compose.yml looks like:
version: '3'
services:
db:
image: postgres
restart: always
environment:
- POSTGRES_USER=${DATABASE_USER}
- POSTGRES_PASSWORD=${DATABASE_PASSWORD}
- POSTGRES_DB=${DB_NAME}
container_name: postgres-db
volumes:
- ./pgdata:/var/lib/postgresql/data
ports:
- "54320:5432"
I then always run this with docker-compose up -d, not starting the container through the Docker Desktop app (though after that command, you should see the new container light up in the app).
Then in .env, I have this critical part:
POSTGRES_HOST=localhost
POSTGRES_PORT=54320
I mapped Docker's internal 5432 to the localhost-accessible 54320 (a suggestion I found here). Doing "5432:5432" as other articles suggest was not working for me, for reasons I don't entirely understand.
Other articles will suggest changing the host to whatever the service name is in your docker-compose.yml (for the example above, it would be db) - this also did not work for me. I believe the "54320:5432" part maps the ports correctly so that host can remain localhost.
Hope this helps others!