dockerコンテナ上で「403 Forbidden」 web表示できない

dockerコンテナを起動後、ページアクセスするも「403 Forbidden」と表示されます。権限などの問題かと思いますが、何が原因なのかをご教示いただければと思います。

各種設定

docker-compose.yml

version: '3' 
services:
  web:
   image: nginx:1.15.6 
   ports:
    - "8000:80" 
   depends_on:
    - app 
   volumes:
    - ./docker/web/default.conf:/etc/nginx/conf.d/default.conf
    - .:/var/www/html 
  app:
   build: ./docker/php 
   volumes:
    - .:/var/www/html 
   depends_on:
    - mysql 
  mysql:
   image: mysql:5.7 
   environment: 
    MYSQL_DATABASE: ****
    MYSQL_USER: root
    MYSQL_PASSWORD: ****
    MYSQL_ROOT_PASSWORD: ****
   ports:
    - "3306:3306"
   volumes: 
    - mysql-data:/var/lib/mysql
volumes: 
  mysql-data:

Docker.file

FROM php:7.2-fpm

# install composer
RUN cd /usr/bin && curl -s http://getcomposer.org/installer| php && ls -s /usr/bin/composer.phar
RUN apt-get update \
&& apt-get install -y \
git \
zip \
unzip \
vim

RUN apt-get update \
    && apt-get install -y libpq-dev \
    && docker-php-ext-install pdo_mysql pdo_pgsql mysqli

WORKDIR /var/www/html

defoult.conf

server {

    listen 80;
    root /var/www/html/;
    index index.php index.html index.htm;

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

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

    location ~ .php$ {
        fastcgi_split_path_info ^(.+.php)(/.+)$;
        fastcgi_pass  app:9000;
        fastcgi_index index.php;

        include       fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }
}

コンテナ起動確認

CONTAINER
1d14940a5fd4e        mysql:5.7           "docker-entrypoint.s…"   4 days ago          Up 37 minutes       0.0.0.0:3306->3306/tcp, 33060/tcp   workspace_mysql_1
27a5f38dc7a5f        nginx:1.15.6        "nginx -g 'daemon of…"   4 days ago          Up 37 minutes       0.0.0.0:8000->80/tcp                workspace_web_1
3a5aea63e4d25        workspace_app       "docker-php-entrypoi…"   4 days ago          Up 37 minutes       9000/tcp                            workspace_app_1

localhost:8000