127.0.0.1   no.docker -> внешний хост, нижние 2 почему-то ссылаются на него
127.0.0.1   docker.frontend
127.0.0.1   docker.backend

server {
    listen 80;
    index index.php index.html;
    server_name docker.frontend(backend);
    error_log  /var/log/nginx/error.log;
    access_log /var/log/nginx/access.log;
    root /root/frontend(backend)/web;

    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;
    }
}