Concept: Use full graph definitions from checkMK metric system

[LarsMichelsen]

As user of the Grafana checkMK datasource I want to be able to add the predefined graphs to my Grafana dashboard.

Acceptance:

• We have a rough concept how the graph definitions (units, scaling) from checkMK can be transported to Grafana
• The transported information is not persited within Grafana. Changes between checkMK updates are applied to Grafana.

Some background information about the checkMK graphing logic:

Each service that has metrics may have a dynamic number of graphs in the checkMK graphing system. The graphs are created based on the the collection of metrics and defined graphs in Check_MK. Most standard graphs are defined in https://github.com/tribe29/checkMK/blob/master/cmk/gui/plugins/metrics/check_mk.py.

When the graphs of a service are requested by a user the check_mk graphing system takes the metrics of the service as input and searches all entries in "graph_info". Each graph_info entry that can be fully populated with the available metrics is rendered for this service.

Example: A service has a metric fan_speed=3200. The graph_info["fan_speed"] entry only requires the "fan_speed" metric to be available. This graph can then be rendered. The metrics list also tells the graph how to draw the different metrics (e.g. as lines or stacked)

Another important structure is the metric_info. It holds entries for each metrics to tell the graphing system which units or colors to use for the single metrics.

The precomputed information can be fetched from the checkMK metric system using the available API calls.

[LarsMichelsen]

Next steps: Research.

• Which kind of plugin is needed?
• What is possible with grafana?