Nginx, PHP-FPM, Docker - 113: Host is unreachable - php

Question

I'm struggling to understand where my error is. I've looked at various answers and tried the remedies, only to find that their solutions did not rectify my problem. I've stripped everything down to the VERY basics to see if I can just get a basic PHP index.php to present itself.
Here is what I'm trying to accomplish at the core:
I have docker-compose standing up 1 network, and 2 services connected to the network. One service is PHP-FPM, and the other is nginx to serve the PHP-FPM. Every time I stand this up, no matter how I seem to configure it, I just get a 502 Bad Gateway, and when I inspect the nginx container logs, I get [error] 29#29: *1 connect() failed (113: Host is unreachable) while connecting to upstream.
./docker-compose.yml
version: "3.7"
networks:
app:
driver: bridge
services:
php:
image: php:7.4-fpm
container_name: php
volumes:
- /home/admin/dev/test/php/www.conf:/usr/local/etc/php-fpm.d/www.conf
- /home/admin/dev/test/src/:/var/www/html
networks:
- app
nginx:
image: nginx:alpine
container_name: nginx
depends_on:
- php
ports:
- "80:80"
- "443:443"
volumes:
- /home/admin/dev/test/src/:/usr/share/nginx/html
- /home/admin/dev/test/nginx/conf.d/app.conf:/etc/nginx/conf.d/app.conf
networks:
- app
./php/www.conf -> /usr/local/etc/php-fpm.d/www.conf
[www]
user = www-data
group = www-data
listen = 0.0.0.0:9000
pm = dynamic
pm.max_children = 5
pm.start_servers = 2
pm.min_spare_servers = 1
pm.max_spare_servers = 3
./nginx/conf.d/app.conf -> /etc/nginx/conf.d/app.conf
server {
listen 80;
server_name localhost;
root /usr/share/nginx/html;
index index.php;
location / {
try_files $uri $uri/ /index.php?$query_string;
}
location ~ \.php$ {
fastcgi_split_path_info ^(.+\.php)(/.+)$;
fastcgi_pass php:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
}
}
./src/index.php -> (php)/var/www/html && (nginx)/usr/share/nginx/html (just for reference)
<?php
phpinfo();
Docker: Docker version 19.03.12, build 48a66213fe
Docker-compose: docker-compose version 1.25.4, build unknown
Environment: Linux localhost.localdomain 5.7.14-200.fc32.x86_64 #1 SMP Fri Aug 7 23:16:37 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux (Fedora 32 Workstation)
I believe I just have a major misunderstanding of PHP-FPM but maybe there is something else.
Update During Troubleshooting
The thought occurred that my overall environment (i.e. Fedora 32) was messing it up. Fedora 32 is not supported out of the box for Docker (had to change the repo settings in /etc/yum.repos.d to get it to work - had to use Fedora 31's repo). So I decided to spin up an Ubuntu 20.0.4 VM and test it there. Now the PHP-FPM and Nginx are talking; I get responses from the PHP-FPM container! However, now even with just the basic script, I'm getting 404 errors, but that is MUCH closer to where I need to be... now to fix the 404.
The exact error is: [error] 30#30: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream

Answer 1

Final Update (Answer)
For anyone coming across this, as of today's date, Docker didn't work with Fedora 32 (some parts did). At least not with the time I had available to troubleshoot/patch. It was a fresh Fedora 32 with no previous docker/docker-compose or anything installed.
I stood up a fresh Fedora 31 and Ubuntu 20.0.4 just to verify my "conclusion". Both worked right out of the box with no extra tweaks.

Answer 2

Can you check if your php-fpm service is running ?
Issue could be the php-fpm service is not running hence the nginx could not connect to it