Install mysql 5.7 CLI client into Amazon Linux 2

# ローカルリポジトリ追加
sudo yum localinstall https://dev.mysql.com/get/mysql80-community-release-el7-1.noarch.rpm

# mysql8.0リポジトリの無効化
sudo yum-config-manager --disable mysql80-community

# mysql5.7リポジトリの有効化
sudo yum-config-manager --enable mysql57-community

# 確認
yum info mysql-community-client.x86_64

# install
sudo yum install mysql-community-client.x86_64