How to connect php and nginx containers together – Docker

I’m trying to create a simple docker project and connect PHP and Nginx containers for a test. but i got this error :

Building php
Sending build context to Docker daemon  2.048kB
Step 1/1 : FROM php:latest
 ---> 52cdb5f30a05
Successfully built 52cdb5f30a05
Successfully tagged test_php:latest

WARNING: Image for service php was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
Building nginx
Sending build context to Docker daemon  3.072kB
Step 1/2 : FROM nginx:latest
 ---> 55f4b40fe486
Step 2/2 : ADD default.conf /etc/nginx/conf.d/default.conf
 ---> 20190910ffec
Successfully built 20190910ffec
Successfully tagged test_nginx:latest
WARNING: Image for service nginx was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
Creating php ... done
Creating nginx ... done
Attaching to php, nginx
php      | Interactive shell
php      | 
nginx    | /docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
nginx    | /docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
php      | php > nginx    | /docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
nginx    | 10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf
nginx    | 10-listen-on-ipv6-by-default.sh: info: /etc/nginx/conf.d/default.conf differs from the packaged version
nginx    | /docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
php exited with code 0
nginx    | /docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
nginx    | /docker-entrypoint.sh: Configuration complete; ready for start up
nginx    | 2022/07/10 05:34:07 [emerg] 1#1: host not found in upstream "php" in /etc/nginx/conf.d/default.conf:14
nginx    | nginx: [emerg] host not found in upstream "php" in /etc/nginx/conf.d/default.conf:14
nginx exited with code 1

Here is the full directory structure of the project:

- docker
   -- nginx
      -- default.conf
      -- Dockerfile
   -- php
      -- Dockerfile
- src
  -- index.php
docker-compose.yml

and this is all files and their contents which i use :

# docker/nginx/default.conf
server {
    listen 80;
    index index.php index.htm index.html;

    root /var/www/html;

    error_log  /var/log/nginx/error.log;
    access_log /var/log/nginx/access.log;

    location ~ .php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(.+.php)(/.+)$;
        fastcgi_pass php:9000;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }
}

# docke/nginx/Dockerfile
FROM nginx:latest
ADD default.conf /etc/nginx/conf.d/default.conf

# docker/php/Dockerfile
FROM php:latest

# src/index.php
<?php
echo phpinfo();

# docker-compose.yml
version: "3.8"
services:
  nginx:
    container_name: nginx
    build: ./docker/nginx
    command: nginx -g "daemon off;"
    links:
      - php
    ports:
      - "80:80"
    volumes:
      - ./src:/var/www/html
  php:
    container_name: php
    build: ./docker/php
    ports:
      - "9000:9000"
    volumes:
      - ./src:/var/www/html
    working_dir: /var/www/html

the main problem occurs when I want to connect the PHP container to the project and without PHP, Nginx will work correctly.