CI: Docker-compose test infrastructure (MySQL topology + ProxySQL)

[renecannao]

Test Infrastructure

Create a reproducible Docker-based test environment for functional testing in GitHub Actions.

Components

• docker-compose.yml with:
  • MySQL 8.4 master (mysql1)
  • MySQL 8.4 replica (mysql2)
  • MySQL 8.4 replica (mysql3)
  • ProxySQL (with writer HG 10 + reader HG 20)
• Initialization scripts:
  • Replication setup (GTID-based)
  • Orchestrator user creation
  • ProxySQL hostgroup configuration
  • ProxySQL remote admin user setup (radmin)

Files to create

• tests/functional/docker-compose.yml
• tests/functional/mysql/init-master.sql
• tests/functional/mysql/init-replica.sh
• tests/functional/proxysql/proxysql.cnf
• tests/functional/orchestrator-test.conf.json (already exists, needs updating)

Acceptance criteria

• docker-compose up -d starts full topology
• Replication is healthy within 30s
• ProxySQL hostgroups configured automatically
• Orchestrator can connect to all services