dockerで環境構築し、localhostにアクセスするも502 Bad Gatewayとなってしまう

Question

docker初学者です。
Docker+Rails6+Puma+Nginx+MySQLで環境構築を完了させ、これからアプリ開発を始めようとしています。

少しページを作って表示されるか確認したところ、エラー画面になってしまい困っております。

ブラウザでhttp://localhost/にアクセスすると、502 Bad Gateway　nginx/1.19.10
と表示されてしまいます。
画像を添付させていただきます。

$ docker-compose logs（webサーバーの部分のみ抜粋）

docker-compose logs
Attaching to remote-work-space_app_1, remote-work-space_web_1, remote-work-space_db_1
web_1  | 172.22.0.1 - - [03/Jul/2021:16:13:22 +0000] "GET / HTTP/1.1" 200 400452 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"
web_1  | 172.22.0.1 - - [03/Jul/2021:17:19:07 +0000] "GET / HTTP/1.1" 200 400473 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"
web_1  | 2021/07/03 17:21:11 [error] 9#9: *5 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/", host: "localhost"
web_1  | 2021/07/03 17:21:11 [error] 9#9: *5 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/500.html", host: "localhost"
web_1  | 172.22.0.1 - - [03/Jul/2021:17:21:11 +0000] "GET / HTTP/1.1" 502 560 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"
web_1  | 2021/07/03 17:21:20 [error] 9#9: *4 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/", host: "localhost"
web_1  | 2021/07/03 17:21:20 [error] 9#9: *4 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/500.html", host: "localhost"
web_1  | 172.22.0.1 - - [03/Jul/2021:17:21:20 +0000] "GET / HTTP/1.1" 502 560 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"
web_1  | 172.22.0.1 - - [03/Jul/2021:17:21:22 +0000] "GET / HTTP/1.1" 502 560 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"
web_1  | 2021/07/03 17:21:22 [error] 9#9: *4 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/", host: "localhost"
web_1  | 2021/07/03 17:21:22 [error] 9#9: *4 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/500.html", host: "localhost"
web_1  | 2021/07/03 17:25:57 [error] 9#9: *14 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/", host: "localhost"
web_1  | 2021/07/03 17:25:57 [error] 9#9: *14 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/500.html", host: "localhost"
web_1  | 172.22.0.1 - - [03/Jul/2021:17:25:57 +0000] "GET / HTTP/1.1" 502 560 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"
web_1  | 172.22.0.1 - - [03/Jul/2021:17:28:46 +0000] "GET / HTTP/1.1" 502 560 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"
web_1  | 2021/07/03 17:28:46 [error] 10#10: *2 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/", host: "localhost"
web_1  | 2021/07/03 17:28:46 [error] 10#10: *2 connect() to unix:///var//www/remote-work-space/tmp/sockets/puma.sock failed (111: Connection refused) while connecting to upstream, client: 172.22.0.1, server: puma, request: "GET / HTTP/1.1", upstream: "http://unix:///var//www/remote-work-space/tmp/sockets/puma.sock:/500.html", host: "localhost"

各種設定ファイル

# Dockerfile（app用）
FROM ruby:3.0.0

RUN apt-get update -qq && \
    apt-get install -y build-essential libpq-dev nodejs vim

RUN apt-get update && apt-get install -y curl apt-transport-https wget && \
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add - && \
echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list && \
apt-get update && apt-get install -y yarn

RUN curl -sL https://deb.nodesource.com/setup_10.x | bash - \
        && apt-get install -y nodejs

RUN mkdir -p /var/www/remote-work-space

WORKDIR /var/www/remote-work-space

ADD Gemfile /var/www/remote-work-space/Gemfile
ADD Gemfile.lock /var/www/remote-work-space/Gemfile.lock

RUN gem install bundler
RUN bundle install

ADD . /var/www/remote-work-space

RUN mkdir -p tmp/sockets
RUN mkdir -p tmp/pids

# containers/nginx/Dockerfile（web用）
FROM nginx:1.19.10

RUN rm -f /etc/nginx/conf.d/*

ADD nginx.conf /etc/nginx/conf.d/remote-work-space.conf

CMD /usr/sbin/nginx -g 'daemon off;' -c /etc/nginx/nginx.conf

# containers/nginx/nginx.conf

upstream puma {
  server unix:///var//www/remote-work-space/tmp/sockets/puma.sock;
}

server {
  listen 80;
  server_name puma;

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

  location ~ ^/assets/ {
    root /var/www/remote-work-space/public;
  }

  client_max_body_size 100m;
  error_page 404 /404.html;
  error_page 505 502 503 504 /500.html;
  try_files $uri/index.html $uri @remote-work-space;
  keepalive_timeout 5;

  location / {
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_pass http://puma;
  }
}

# docker-compose.yml

version: "3"
services:
  app:
    build:
      context: .
    env_file:
      - ./environments/db.env
    command: bundle exec puma -C config/puma.rb
    volumes:
      - .:/var/www/remote-work-space
      - public-data:/var/www/remote-work-space/public
      - tmp-data:/var/www/remote-work-space/tmp
      - log-data:/var/www/remote-work-space/log
    depends_on:
      - db
  db:
    image: mysql:5.7
    env_file:
      - ./environments/db.env
    volumes:
      - db-data:/var/lib/mysql
  web:
    build:
      context: containers/nginx
    volumes:
      - public-data:/var/www/remote-work-space/public
      - tmp-data:/var/www/remote-work-space/tmp
    ports:
      - 80:80
    depends_on:
      - app
volumes:
  public-data:
  tmp-data:
  log-data:
  db-data:

# config/puma.rb

threads_count = ENV.fetch("RAILES_MAX_THREADS") { 5 }.to_i
threads threads_count, threads_count
port ENV.fetch("PORT") { 3000 }
environment ENV.fetch("RAILES_ENV") { "development" }
plugin :tmp_restart

app_root = File.expand_path("../..", __FILE__)
bind "unix://#{app_root}/tmp/sockets/puma.sock"

stdout_redirect "#{app_root}/log/puma.stdout.log", "#{app_root}/log/puma.stderr.log"

パーミッション

$ ls -ld /var/www/remote-work-space/tmp/sockets/puma.sock
→ srwxrwxrwx 1 root root 0 Jul  4 05:41 /var/www/remote-work-space/tmp/sockets/puma.sock

$ ls -ld /var/www/remote-work-space/tmp/sockets
→ drwxr-xr-x 2 root root 4096 Jul  4 05:41 /var/www/remote-work-space/tmp/sockets

$ ls -ld /var/www/remote-work-space/tmp
→ drwxr-xr-x 7 root root 4096 Jul  3 07:49 /var/www/remote-work-space/tmp

$ ls -ld /var/www/remote-work-space
→ drwxr-xr-x 32 root root 1024 Jul  3 15:37 /var/www/remote-work-space

$ ls -ld /var/www
→ drwxr-xr-x 1 root root 4096 Jul  3 07:33 /var/www

$ ls -ld /var
→ drwxr-xr-x 1 root root 4096 Jul  3 07:33 /var

以上です。
どうすれば解決できるのでしょうか。
他のteratailの投稿やQiitaなども調べましたが、なかなか解決策が見つかりません。
どなたかご教示いただけますと幸いです。
よろしくお願いいたします。

Answer 1

自己解決できました。
nginx.confの中で一部記載を誤っていました。

（誤）
upstream puma {
server unix:///var//www/remote-work-space/tmp/sockets/puma.sock;
}

（正）
upstream puma {
server unix:///var/www/remote-work-space/tmp/sockets/puma.sock;
}

varとwwwの間が//になってしまっていたのが原因のようでした。