Fix CloudWatch agent custom dimensions not appearing in metrics

[akuzminsky]

Summary

• Fix environment dimension not appearing in CloudWatch metrics
• Add InstanceId and AutoScalingGroupName dimensions to all metrics

Problem

The global append_dimensions in CloudWatch agent config only supports these AWS metadata variables:

• ${aws:InstanceId}
• ${aws:InstanceType}
• ${aws:ImageId}
• ${aws:AutoScalingGroupName}

Any other key-value pairs are silently ignored. Our custom environment dimension was not appearing in metrics.

Solution

• Add append_dimensions with environment to each metric type individually (cpu, mem, disk, diskio, netstat, processes, swap, procstat)
• Use global append_dimensions for the supported AWS variables (InstanceId, AutoScalingGroupName)

Result

All metrics will now have these dimensions:

• InstanceId - EC2 instance ID
• AutoScalingGroupName - ASG name (if applicable)
• environment - Puppet environment (development/sandbox/production)

Test plan

• Deploy to development OpenVPN or Jumphost
• Verify metrics in CloudWatch have environment dimension
• Verify metrics have InstanceId dimension