Docker Nginx reverse proxy to separate container - docker

Question

I'm having trouble creating a reverse proxy and having it point at apps that are in other containers.
What I have now is a docker-compose for Nginx, and then I want to have separate docker-containers for several different apps and have Nginx direct traffic to those apps.
My Nginx docker-compose is:
version: "3"
services:
nginx:
image: nginx:alpine
volumes:
- ./default.conf:/etc/nginx/conf.d/default.conf
My default.conf is:
server {
listen 80;
server_name localhost;
location / {
root /usr/share/nginx/html;
index index.html index.htm;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /usr/share/nginx/html;
}
}
server {
listen 80;
server_name www.mydomain.com;
location /confluence {
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Server $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://192.168.1.50:8090/confluence;
}
}
I can access confluence directly at: http://192.168.1.50:8090/confluence
My compose for confluence is:
version: "3"
services:
db:
image: postgres:9.6
container_name: pg_confluence
env_file:
- env.list
ports:
- "5434:5432"
volumes:
- ./pg_conf.sql:/docker-entrypoint-initdb.d/pg_conf.sql
- dbdata:/var/lib/postgresql/data
confluence:
image: my_custom_image/confluence:6.11.0
container_name: confluence
volumes:
- confluencedata:/var/atlassian/application-data/confluence
- ./server.xml:/opt/atlassian/confluence/conf/server.xml
environment:
- JVM_MAXIMUM_MEMORY=2g
ports:
- "8090:8090"
depends_on:
- db
volumes:
confluencedata:
dbdata:
I am able to see the Nginx "Welcome" screen when I hit mydomain.com but if I hit mydomain.com/confluence it gives a not found.
So it looks like Nginx is running, just not sending the traffic to the other container properly.
========================
=== Update With Solution ===
========================
I ended up switching to Traefik instead of Nginx. When I take the next step and start learning k8s this will help as well.
Although these network settings are what you need even if you stick with Nginx, I just didn't test them against Nginx, so hopefully they are helpful no matter which one you end up using.
For the confluence docker-compose.yml I added:
networks:
proxy:
external: true
internal:
external: false
services:
confluence:
...
networks:
- internal
- proxy
db:
...
networks:
- internal
And for the traefik docker-compose.yml I added:
networks:
proxy:
external: true
services:
reverse-proxy:
networks:
- proxy
I had to create the network manually with:
docker network create proxy

Answer 1

It is not really how to use docker the correct way.
If you are in a production environment, use a real orchestration tools (nowaday Kubernetes is the way to go)
If you are on you computer, you can reference a name of a container (or an alias) only if you use the same network AND this network is not the default one.
A way is to have only one docker-compose file.
Another way is to use the same network across your docker-compose.
Create a network docker network create --driver bridge my_network
use it on each docker-compose you have:
networks:
default:
external:
name: my_network