Research and prototype resource usage and cost tracking

[johnstcn]

Overview

Umbrella issue for research relating to resource usage and cost tracking feature.

Tasks

• Prototype extracting resource usage data from workspace_builds.provisioner_state (est: 1-2 days)
• Prototype a basic report of the above by resource type / workspace / user (est: 1-2 days)
• Investigate potential data storage backends for above data (est: 1-2 days)
• Write/update RFC with discoveries from the above (est: 1 day)

Stretch goals

• Prototype determining cost data from above using existing 3rd party tooling (est: 1-2 days)

Questions / Expected Outcomes

• ‼️ Can we reliably determine resource usage (units/interval) based solely on Terraform state?
• ‼️ Can a small PostgreSQL deployment reasonably handle all of the historical usage data from dev.coder.com, or do we need to investigate alternative backends?
• Can Grafana comfortably handle 80% of the use cases of a reporting dashboard while still remaining performant?
• (Optional) Can we determine the cost of resources to within a reasonable level of accuracy using existing tools without having to implement our own?

[johnstcn]

PoC branch: https://github.com/coder/coder/compare/cj/hack/exp-resources