Nginx as a reverse proxy inside docker container - docker

Question

I'm trying to use nginx as a reverse proxy inside a container points to the different PHP application container.
My PHP container gets requests from external port 8080 and forwards it to internal 80. I want my nginx to get listen to port 80 and forward the request to the PHP container on port 8080 but have issues redirecting the request.
My nginx Dockerfile:
FROM nginx:latest
COPY default.conf /etc/nginx/conf.d/default.conf
My nginx default.conf:
server {
listen 80;
error_page 497 http://$host:80$request_uri;
client_max_body_size 32M;
underscores_in_headers on;
location / {
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_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Host $host;
proxy_pass http://php-container:8080;
proxy_read_timeout 90;
proxy_http_version 1.1;
}
}
I've tried deploying it via docker-compose with the above yml file, but got the same error when CURL to the nginx.
When CURL to HTTP://localhost:8080 (PHP application) and also to HTTP://localhost:80 (nginx) there's a log output from the docker-compose log.
But when CURL to nginx, I got the above error:

Answer 1

You have a misconfiguration here.
nginx (host:80 -> container:8080)
php-app (host:8080 -> container:80)
Nginx can't reach of "localhost" of another container because it's a different container network.
I suggest you create a docker network --network and place both containers to the network. Then in Nginx config, you can refer php-app container by name.
proxy_read_timeout 90;
proxy_redirect http://localhost:80/ http://php-container:8080/;
Besides you can expose only the Nginx port and your backend will be safe.