Dockerを起動しても、http://localhost:3000に接続できない

前提・実現したいこと

Dockerにlocalhost:3000で接続したいです。どなたかアドバイスを頂けないでしょうか？

発生している問題・エラーメッセージ

※chrome

このサイトにアクセスできませんlocalhost で接続が拒否されました。
次をお試しください

接続を確認する
プロキシとファイアウォールを確認する
ERR_CONNECTION_REFUSED

https://qiita.com/chisaki0606/items/a4b42af5c4735c94057a
↑こちらの記事を参考にDockerでRailsの環境構築を行いました。その後、Dockerの再起動をしたいと思い、docker-compose downを実行した後、docker-compose upを行いました。
再びDockerを起動すると、http://localhost:3000では、”localhost で接続が拒否されました。”と出るようになってしまいました。

試したこと

https://web.plus-idea.net/on/docker-web-server-access-denied/
↑こちらを参考に

docker exec -it ＜起動したコンテナ名＞ bash

>>Error response from daemon: Container 7049dd94e1802520be68b5bf90d136fbc5d74bf4557f707a04bf3a2383e3aed2 is not running

curl http://localhost:8080/

>><!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

ポートフォワードを確認する

docker run -p 8080:3000 –name ＜起動するコンテナ名＞

>>docker: invalid reference format.
See 'docker run --help'.

Docker logs 7049dd94e180

>>/usr/local/bundle/gems/webpacker-4.3.0/lib/webpacker/configuration.rb:95:in `rescue in load': Webpacker configuration file not found /myapp/config/webpacker.yml. Please run rails webpacker:install Error: No such file or directory @ rb_sysopen - /myapp/config/webpacker.yml (RuntimeError)
        from /usr/local/bundle/gems/webpacker-4.3.0/lib/webpacker/configuration.rb:91:in `load'
        from /usr/local/bundle/gems/webpacker-4.3.0/lib/webpacker/configuration.rb:88:in `data'
        .
        .
        .
        from /usr/local/bundle/gems/bootsnap-1.7.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
        from bin/rails:4:in `<main>'
=> Booting Puma
=> Rails 5.2.4.4 application starting in development 
=> Run `rails server -h` for more startup options
Exiting

Error: No such file or directory @ rb_sysopen - /myapp/config/webpacker.yml (RuntimeError)Docker logsのエラーからwebpacker.ymlが足りないのだと思いrails webpacker:installし、もう一度を行いましたが結果は変わりませんでした。

Docker logs 7049dd94e180

>>上記と同じエラー

補足情報（FW/ツールのバージョンなど）

Mac OSX
ruby 2.6.3
Rails 6.0.3.4
webpacker 4.3.0
Docker version 20.10.2

Dockerfile
1FROM ruby:2.7
2RUN apt-get update -qq && \
3    apt-get install -y apt-utils \
4                       build-essential \
5                       libpq-dev \
6                       nodejs \
7                       default-mysql-client \
8                       yarn
9RUN mkdir /myapp
10WORKDIR /myapp
11COPY Gemfile /myapp/Gemfile
12COPY Gemfile.lock /myapp/Gemfile.lock
13RUN bundle install
14COPY . /myapp
15USER postgres
16
17
18# Add a script to be executed every time the container starts.
19COPY entrypoint.sh /usr/bin/
20RUN chmod +x /usr/bin/entrypoint.sh
21ENTRYPOINT ["entrypoint.sh"]
22EXPOSE 3000
23
24# Start the main process.
25CMD ["rails", "server", "-b", "0.0.0.0"]
26
27# Railsに必要なパッケージをインストール
28RUN apt-get update -qq && apt-get install -y nodejs
29RUN curl -sL https://deb.nodesource.com/setup_10.x | bash - \
30    && apt-get install -y nodejs
31
32EXPOSE 8080
33

docker-compose.yml

version: '3'
services:
  db:
    image: postgres
    volumes:
      - ./tmp/db:/var/lib/postgresql/data
    environment:
      POSTGRES_PASSWORD: 'postgres'
  web:
    build: .
    command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3000 -b '0.0.0.0'"
    volumes:
      - .:/myapp
    ports:
      - "3000:3000"
    depends_on:
      - db

  postgres:
    image: postgres:13
    user: postgres

Gemfile
1source 'https://rubygems.org'
2git_source(:github) { |repo| "https://github.com/#{repo}.git" }
3
4
5gem 'rails', '~> 6.0.3.4'
6gem 'puma', '~> 3.11'
7gem 'sassc-rails', '2.1.2'
8gem 'uglifier', '>= 1.3.0'
9gem 'coffee-rails', '~> 4.2'
10gem 'turbolinks', '~> 5'
11gem 'jbuilder', '~> 2.5'
12gem 'bootsnap', '>= 1.1.0', require: false
13gem 'bootstrap', '~> 4.5.0'
14gem 'jquery-rails'
15gem 'webpacker', '~> 4.0'
16
17
18group :development, :test do
19  gem 'rspec-rails'
20  gem 'sqlite3'
21  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
22end
23
24group :development do
25  gem 'web-console', '>= 3.3.0'
26  gem 'listen', '>= 3.0.5', '< 3.2'
27  gem 'spring'
28  gem 'spring-watcher-listen', '~> 2.0.0'
29end
30
31group :test do
32  gem 'capybara', '>= 2.15'
33  gem 'selenium-webdriver'
34  gem 'chromedriver-helper'
35end
36
37group :production do
38  gem 'pg'
39end
40
41gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
42

webpacker.yml

webpacker.yml
1# Note: You must restart bin/webpack-dev-server for changes to take effect
2
3default: &default
4  source_path: app/javascript
5  source_entry_path: packs
6  public_root_path: public
7  public_output_path: packs
8  cache_path: tmp/cache/webpacker
9  check_yarn_integrity: false
10  webpack_compile_output: true
11
12  # Additional paths webpack should lookup modules
13  # ['app/assets', 'engine/foo/app/assets']
14  resolved_paths: []
15
16  # Reload manifest.json on all requests so we reload latest compiled packs
17  cache_manifest: false
18
19  # Extract and emit a css file
20  extract_css: false
21
22  static_assets_extensions:
23    - .jpg
24    - .jpeg
25    - .png
26    - .gif
27    - .tiff
28    - .ico
29    - .svg
30    - .eot
31    - .otf
32    - .ttf
33    - .woff
34    - .woff2
35
36  extensions:
37    - .mjs
38    - .js
39    - .sass
40    - .scss
41    - .css
42    - .module.sass
43    - .module.scss
44    - .module.css
45    - .png
46    - .svg
47    - .gif
48    - .jpeg
49    - .jpg
50
51development:
52  <<: *default
53  compile: true
54
55  # Verifies that correct packages and versions are installed by inspecting package.json, yarn.lock, and node_modules
56  check_yarn_integrity: true
57
58  # Reference: https://webpack.js.org/configuration/dev-server/
59  dev_server:
60    https: false
61    host: localhost
62    port: 3035
63    public: localhost:3035
64    hmr: false
65    # Inline should be set to true if using HMR
66    inline: true
67    overlay: true
68    compress: true
69    disable_host_check: true
70    use_local_ip: false
71    quiet: false
72    pretty: false
73    headers:
74      'Access-Control-Allow-Origin': '*'
75    watch_options:
76      ignored: '**/node_modules/**'
77
78
79test:
80  <<: *default
81  compile: true
82
83  # Compile test packs to a separate directory
84  public_output_path: packs-test
85
86production:
87  <<: *default
88
89  # Production depends on precompilation of packs prior to booting for performance.
90  compile: false
91
92  # Extract and emit a css file
93  extract_css: true
94
95  # Cache manifest.json for performance
96  cache_manifest: true
97