Controller Manager API Server Test

The Kubernetes Controller Manager is a key control plane component that interacts with the API Server to manage cluster resources. It runs various controllers, like Node, Replication, and Endpoint controllers, ensuring desired states are maintained. The Controller Manager communicates with the API Server to retrieve resource states and submit updates, automating tasks like scaling, rolling updates, and failover. It plays a vital role in maintaining the cluster's consistency and desired operational state.

Monitoring the Controller Manager ensures Kubernetes controllers function properly to maintain the desired cluster state. Issues like failures, delays, or resource drift can disrupt operations like scaling, scheduling, or failovers. Proactive monitoring helps identify and resolve bottlenecks, ensuring reliable orchestration, resource synchronization, and smooth cluster functionality under varying workloads.

The Controller Manager API Server Test continuously monitors Controller Manager client certificate expiration and allows administrators to take preventive actions if the number is very high before majority of client lose access to API Server,

Target of the test : A Kubernetes Master Node

Agent deploying the test : A remote agent

Outputs of the test : One set of results for the target Kubernetes Master node API Server object being monitored

Configurable parameters for the test

Parameter	Description
Test Period	How often should the test be executed.
Host	The IP address of the host for which this test is to be configured.
Port	Specify the port at which the specified Host listens. By default, this is 6443.
Timeout	Specify the duration (in seconds) beyond which the test will timeout in the Timeout text box. The default value is 10 seconds.
Metric URL	Each of the Kubernetes system components expose monitoring metrics through /metrics endpoint of the HTTP server. For components that don't expose endpoint by default, refer official Kubernetes distribution documentation site. Specify the metric URL textbox.

Measurements made by the test

Measurement	Description	Measurement Unit	Interpretation
Client certificate expirations	Indicates the number of certificate expirations measured during last measurement period.	Number	Kubernetes client certificates issued by default have a validity of 1 year unless specified otherwise.