Failed to open stream: Connection refused

[marinmatosevic]

I have local docker setup with nginx as reverse proxy, self-signed SSL certs, mariadb, and wordpress.
Everything works well except when fetching resources on the local domain.

Let’s say the domain name is myapp.local. I have added this in the /etc/hosts and the site is loading on this domain over https.
Problem occurs when php functions like file_get_contents() or simplexml_load_file() are fetching local assets.
For an example: file_get_contents('https://myapp.local/icon.svg');

Then I get a warning:

Failed to open stream: Connection refused

Here is my docker-compose file:
${DOMAIN} is set to myapp.local in .env file.

version: '3.6'
services: 

  nginx:
    container_name: myapp-nginx
    image: nginx:latest   
    ports:
      - 80:80
      - 443:443
    volumes:
      - ./config/nginx.conf:/tmp/default.template
      - ./certs:/etc/certs
      - wp_data:/var/www/html:rw,cached
      - ./www:/var/www/html/wp-content
    depends_on:
      - wordpress  
    restart: always
    entrypoint: /bin/bash -c 'cat /tmp/default.template | sed "s/\\\$$domain/${DOMAIN}/g" > /etc/nginx/conf.d/default.conf && nginx -g "daemon off;"'      
    networks:
      webnet:
        aliases:
          - myapp.local

  mysql:
    container_name: myapp-mysql
    image: mariadb:latest    
    volumes:
      - ./db_data:/var/lib/mysql
      - ./config/db.cnf:/etc/mysql/conf.d/db.cnf
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_USER: root
      MYSQL_PASSWORD: root
      MYSQL_DATABASE: myapp
    restart: always
    ports:
      - 3306:3306
    networks:
      - webnet    

  wordpress:
    container_name: myapp-wordpress
    image: wordpress:php8.0-fpm   
    volumes:
      - ./config/php.ini:/usr/local/etc/php/conf.d/php.ini
      - wp_data:/var/www/html:rw,cached
      - ./www:/var/www/html/wp-content
    depends_on:
      - mysql
    restart: always
    environment:
      WORDPRESS_DB_NAME: myapp
      WORDPRESS_TABLE_PREFIX: wp_
      WORDPRESS_DB_HOST: mysql
      WORDPRESS_DB_USER: root
      WORDPRESS_DB_PASSWORD: root
      WORDPRESS_DEBUG: 1  
    networks:
      - webnet
    extra_hosts:
      - "myapp.local:127.0.0.1"

networks:
  webnet:
    external: true
    driver: bridge

volumes:
  db_data: {}
  wp_data: {}

nginx conf:

server {
    listen      80;
    listen [::]:80;
    server_name $domain;
    return 301 https://$host$request_uri;
}

server {
    listen      443           ssl http2;
    listen [::]:443           ssl http2;
    server_name               $domain www.$domain;

    ssl_certificate           /etc/certs/$domain.pem;
    ssl_certificate_key       /etc/certs/$domain-key.pem;

    add_header                Strict-Transport-Security "max-age=31536000" always;

    ssl_session_cache         shared:SSL:20m;
    ssl_session_timeout       10m;

    ssl_protocols             TLSv1 TLSv1.1 TLSv1.2;
    ssl_prefer_server_ciphers on;
    ssl_ciphers               "ECDH+AESGCM:ECDH+AES256:ECDH+AES128:!ADH:!AECDH:!MD5;";

    root /var/www/html;
    index index.php;

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

    gzip on;
    gzip_disable "msie6";

    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_buffers 16 8k;
    gzip_http_version 1.1;
    gzip_min_length 0;
    gzip_types text/plain application/javascript text/css text/xml application/xml application/xml+rss text/javascript application/vnd.ms-fontobject application/x-font-ttf font/opentype;

    client_max_body_size 100M;

    location ~ /.well-known/acme-challenge {
        allow all;
        root /var/www/html;
    }

    location / {
        try_files $uri $uri/ /index.php$is_args$args;
    }

    location ~ \.php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass wordpress:9000;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
        fastcgi_read_timeout 300; 
    }

    location ~ /\.ht {
            deny all;
    }

    location = /favicon.ico {
            log_not_found off; access_log off;
    }
    location = /robots.txt {
            log_not_found off; access_log off; allow all;
    }

    location ~* \.(css|gif|ico|jpeg|jpg|js|png)$ {
        expires max;
        log_not_found off;
    }

}

I’m struggling with this for weeks. I’ve tried numerous options and I’m stuck. What am I missing here? Any help is appreciated.

p.s.: rewriting/swapping functions isn’t an option since these are coming from third-party plugins.