Summary:

• Look into different options for parsing PromQL, so that it can later be modified to add project labels. current code first sends a query to Prometheus to get a list of known metric names. Those are then used to determine which part of queries is a metric name, function, label and so on. The current code can't work without this. It's expected, that queries contained in Aodh alarms will need to perform query modification on yet unknown metric names.
• We need either:
  • Query modification needs to work on all PromQL queries no matter the data stored in Prometheus
  • As a less preferred option, the modification should work on all ceilometer metrics no matter the data stored in Prometheus. For non-ceilometer metrics not currently stored in prometheus, a failure which would prevent non-admin users to access such metrics is acceptable.

Goal:

• Search for all available options
• For each option, provide a set of pros and cons
• Provide a recommendation for the final solution. This and other possible solutions should be discussed with the team at the end.

TimeBox:

• 3 days

Deliverables/Outcomes:

• A google doc with a detailed description of the problem, description of the current solution and a list of all the options for solving the issue. For each option, include all relevant links. Provide a short description of each option as well as perceived pros and cons of each. Provide a detailed plan on how the final solution should be done. Provide POCs whenever they'd seem helpful.