MySQL Monitoring

[Vonng]

We already have PostgreSQL monitoring. Why not monitor existing MySQL instance either?

Since we need that during Migration from MySQL to PostgreSQL. 😊

We already have MySQL exporter for that purpose. We can organize MySQL monitoring targets as PGRDS.

To achieve that:

• [x] Add mysqld_exporter to repo_packages
• [ ] New playbook mysql-monitor.yml to deploy and register existing MySQL
• [ ] Dashboards for MySQL instances (MySQL Overview/Cluster/Instance/Database)
• [ ] Local Testing Environment for Example MySQL.