NLB target group registration logic in Puppet

[akuzminsky]

Parent Epic

Part of #232 - Percona Server Puppet Integration

Migrated from infrahouse/terraform-aws-percona-server#30

Description

Implement Puppet logic to register instances with the appropriate NLB target group based on role.

Registration Rules

Role	Target Group
Master	Write TG
Replica	Read TG

Puppet Implementation

class percona::target_group_registration {
  $role = $facts['percona_role']  # 'master' or 'replica'
  $write_tg = $facts['percona_write_tg_arn']
  $read_tg = $facts['percona_read_tg_arn']
  $instance_id = $facts['ec2_instance_id']
  
  if $role == 'master' {
    exec { 'register-write-tg':
      command => "aws elbv2 register-targets --target-group-arn ${write_tg} --targets Id=${instance_id}",
      unless  => "aws elbv2 describe-target-health --target-group-arn ${write_tg} | grep ${instance_id}",
    }
  } else {
    exec { 'register-read-tg':
      command => "aws elbv2 register-targets --target-group-arn ${read_tg} --targets Id=${instance_id}",
      unless  => "aws elbv2 describe-target-health --target-group-arn ${read_tg} | grep ${instance_id}",
    }
  }
}

Role Determination

Role is determined during bootstrap:

1. Try to acquire master lock
2. If won and no existing master -> become master
3. Otherwise -> become replica

Events Handled by Puppet

Event	Action
Initial master boot	Register to write TG
Initial replica boot	Register to read TG
Replica dies (replacement)	Register to read TG

Note: Failover registration handled by Orchestrator hooks, not Puppet

Acceptance Criteria

• Master registered to write TG
• Replicas registered to read TG
• Registration idempotent
• Health checks pass after registration