github actionsでMysql2::Error::ConnectionErrorがでてDBが作成できない

閲覧いただきありがとうございます。

発生している問題・エラーメッセージ

表題についてですが、github actionsで自動テスト・自動フォーマットを実行しているのですが、以下のようなエラーが出てDBを作成することができなくなりました。

Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
Couldn't create 'tooling_development' database. Please check your configuration.
rails aborted!
Mysql2::Error::ConnectionError: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
bin/rails:4:in `<main>'
Tasks: TOP => db:create
(See full trace by running task with --trace)
##[error]Process completed with exit code 1.

3/15にまでは正しくDBが作成されていましたが、3/17日から突然できなくなりました。
開発環境ではDocker-composeを使用しているのですが、そちらは正しくDBが作成されます。
どなたかご助言いただけないでしょうか？

該当のソースコード

yaml
1
2# .github/workflows/ci.yml
3
4name: CI
5
6on: [push]
7
8jobs:
9  build:
10    runs-on: ubuntu-latest
11
12    services:
13      db:
14        image: mysql:5.7
15        env:
16          MYSQL_ROOT_PASSWORD: password
17          MYSQL_DATABASE: root
18        ports:
19          - 3306
20
21    steps:
22      - uses: actions/checkout@v1
23
24      - name: Set up Ruby 2.6
25        uses: actions/setup-ruby@v1
26        with:
27          ruby-version: 2.6.x
28
29      - name: mysql set up
30        run: |
31          sudo apt-get update
32          sudo apt-get install libmysqlclient-dev
33      - name: yarn install
34        run: yarn install
35
36      - name: Build and test with rails
37        run: |
38          gem install bundler
39          bundle install --jobs 4 --retry 3
40          bundle exec rails
41          cp config/database.yml.ci config/database.yml
42      - name: Cache gems
43        uses: actions/cache@preview
44        with:
45          path: vendor/bundle
46          key: ${{runner.os}}-gem-${{hashFiles('**/Gemfile.lock')}}
47          restore-keys: ${{runner.os}}-gem-
48
49      - name: Cache node_modules
50        uses: actions/cache@preview
51        with:
52          path: ./node_modules
53          key: ${{runner.os}}-node-${{hashFiles('**/yarn.lock')}}
54          restore-keys: ${{runner.os}}-node-
55          
56      - name: Create db
57        run: |
58          bundle exec rails db:create
59      - name: Run rubocop
60        run: bundle exec rubocop
61
62      - name: Run rspec
63        env:
64          GOOGLE_API_KEY: ${{ secrets.GOOGLE_API_KEY }}
65        run: bundle exec rspec

yaml
1# database.yml
2
3# MySQL. Versions 5.5.8 and up are supported.
4#
5# Install the MySQL driver
6#   gem install mysql2
7#
8# Ensure the MySQL gem is defined in your Gemfile
9#   gem 'mysql2'
10#
11# And be sure to use new-style password hashing:
12#   https://dev.mysql.com/doc/refman/5.7/en/password-hashing.html
13#
14default: &default
15  adapter: mysql2
16  encoding: utf8mb4
17  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
18  username: root
19  password: root
20  host: localhost
21
22development:
23  <<: *default
24  database: tooling_development
25
26# Warning: The database defined as "test" will be erased and
27# re-generated from your development database when you run "rake".
28# Do not set this db to the same as development or production.
29test:
30  <<: *default
31  database: tooling_test
32
33# As with config/credentials.yml, you never want to store sensitive information,
34# like your database password, in your source code. If your source code is
35# ever seen by anyone, they now have access to your database.
36#
37# Instead, provide the password as a unix environment variable when you boot
38# the app. Read https://guides.rubyonrails.org/configuring.html#configuring-a-database
39# for a full rundown on how to provide these environment variables in a
40# production deployment.
41#
42# On Heroku and other platform providers, you may have a full connection URL
43# available as an environment variable. For example:
44#
45#   DATABASE_URL="mysql2://myuser:mypass@localhost/somedatabase"
46#
47# You can use this database configuration with:
48#
49#   production:
50#     url: <%= ENV['DATABASE_URL'] %>
51#
52production:
53  <<: *default
54  database: tooling_production
55  username: tooling
56  password: <%= ENV['tooling_DATABASE_PASSWORD'] %>
57

補足情報（FW/ツールのバージョンなど）

Rails 6.0.2
ruby 2.6.5
mysql 5.7
開発環境ではDocker-compose使用

試したこと

・database.ymlのホスト名をlocalhostから127.0.0.1に変更→hostが見つからないエラーが出て断念
・DB起動を待つため30秒sleepしてみる→状況変わらず
・libmysqlclient-devを常に最新のものを取得できるようにupgradeコマンドを追加してみる→状況変わらず
・database.ymlからsocketを設定してみる→状況変わらず
socket: /var/run/mysqld/mysqld.sock