K8s monitoring

Problems:

• Metrics about DB and "host" the DB running  on are wrong (we use node, not pod metrics). This makes some data where we compare MySQL parameters and "host"   wrong  (for DBA, Developer)
• There is no way to get any understanding about capacity and usage of K8s clusters  (for DBA) 
• K8s clusters are added to PMM but there is no way to manage them except one special page. They are not entities in PMM, so we can't create good dashboards for them or combine K8s and DB entities. For example, build some graph of relations between k8s clusters and DB's in PMM dashboards and inventory. (for Developer, DBA)
• Allow user to drill down from Environment  ->K8s -> pod -> DB   (example) : K8s Overview, K8s Summary, Containers overview, container summary > MySQL/mongoDB  summary ) 
• Execute Advisors (Checks) against K8s cluster. WE wand to be able to operate with it as we have Services/nodes we have in advisors. 

Note:

In PMM terms K8s cluster is more related to Services if we speak about "What we are monitoring " and more Node if we look at it as a container for other objects.    

 As for now, PMM  assumes  Node and Services are only related objects. ad There is no  inheritance for nodes (no way to have Node1-> node2->node3->servece1 )

Considering K8s can change forms it looks like more as Services as Nodes usually more 'containers' not applications 

UI/UX: 

1. pmm-admin add k8s   -name myK8s  -config-file=....

Acceptance criteria:

• TBD 
• User able to add  K8s cluster into PMM and specify label(s) (Environment)  using UI and CLI
• User able to see metrics about NODES in K8s cluster  (Autodiscovery? )
• User able to see Container metrics (Autodiscovery? )
• Containers and Services are presented on the same dashboards  as bare-metal services and nodes so the user able to see DB  metrics together with Node/container metrics 

Out of scope: 

• services metrics (will be added by operators )

Suggested implementation:
TBD

How to test:
TBD

Details: