docker and nginx: How to reverse proxy multiple postgresql databases - postgresql

Question

I am having a docker container with multiple postgresql databases:
version: "3.7"
services:
nginx:
image: nginx:1.18.0-alpine
ports:
- 8028:80
volumes:
- ./nginx/localhost/conf.d:/etc/nginx/conf.d
depends_on:
- webapp
networks:
- postgresql_network
postgresql:
image: "postgres:13-alpine"
restart: always
volumes:
- type: bind
source: ../DO_NOT_DELETE_POSTGRESQL_DATA
target: /var/lib/postgresql/data
environment:
POSTGRES_DB: db1
POSTGRES_USER: simha
POSTGRES_PASSWORD: krishna
PGDATA: "/var/lib/postgresql/data/pgdata"
networks:
- postgresql_network
postgresql2:
image: "postgres:13-alpine"
restart: always
volumes:
- type: bind
source: ../DO_NOT_DELETE_POSTGRESQL_DATA2
target: /var/lib/postgresql/data
environment:
POSTGRES_DB: db2
POSTGRES_USER: simha
POSTGRES_PASSWORD: krishna
PGDATA: "/var/lib/postgresql/data/pgdata"
networks:
- postgresql_network
networks:
postgresql_network:
driver: bridge
Now I can expose two different ports for each of the postgresq instance and access them differently from host (like localhost 5432 and localhost 5445)
But instead of that i want to handle them using different domain names.
like pg1.docker.db, port 8028 (nginx port) and pg.docker.db, port 8028 (nginx port) and using nginx reverse proxy them internally to different docker containers using postgresql and postgresql2
and in the host /etc/hosts I will have
127.0.0.1 pg1.docker.db
127.0.0.1 pg2.docker.db
I am not sure, but something similar. Can someone say I am doing right
## WEBSERVER
upstream webapp {
server webapp:8000;
}
server {
listen 80;
location / {
proxy_pass http://webapp;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
}
}
## POSTGRESQL DBS
upstream postgres {
server postgresql:5432;
}
upstream postgres2 {
server postgresql2:5432;
}
server {
listen 80 so_keepalive=on;
server_name db1.domain.my;
proxy_pass postgres;
}
server {
listen 80 so_keepalive=on;
server_name db2.domain.my;
proxy_pass postgres2;
}
I find people using stream and http. Will the above also work. Or should I do something

Answer 1

Redirecting http requests based on domain name is pretty easy.
You can use something like this:
http {
server {
listen 80;
server_name pg1.docker.db
location / {
...
}
}
server {
listen 80;
server_name pg2.docker.db;
location / {
...
}
}
}
But the problem here is that nginx forward only http request to servers, so unless you have a web-base interface behind your containers, it's not going to work properly.