Observability Indicator

OBI is the short name of Observability Indicator, it's used to get the data from various metric/log/trace tools and try to get a consistent view for Arbiter.

You can check the custom resource definition in the arbitor repostiroy using path 'manifests/crds/arbiter.k8s.com.cn_observabilityindicants.yaml'.

Here we use a sample OBI resource to explain each configuration.

OBI to read CPU usage from metric server

apiVersion: arbiter.k8s.com.cn/v1alpha1
kind: ObservabilityIndicant
metadata:
  name: prometheus-node-cpu
  namespace: arbiter-test
spec:
  metric:
    historyLimit: 1
    metricIntervalSeconds: 30
    metrics:
      cpu:
        aggregations: [ ]
        description: cpu
        query: (sum(count(node_cpu_seconds_total{mode="idle",node="{{.metadata.name}}"}) by (mode, cpu)) - sum(irate(node_cpu_seconds_total{mode="idle",node="{{.metadata.name}}"}[5m])))*1000
        unit: 'm'
    timeRangeSeconds: 3600
  source: prometheus
  targetRef:
    group: ""
    index: 0
    kind: Node
    labels:
      "data-test": "data-test"
    name: ""
    namespace: ""
    version: v1
status:
  conditions: []
  phase: ""
  metrics: {}

In the sample above, we have the following configuration:

1. metadata, that's the default for all Kubernetes resources
2. source under spec, it's the type of observability tool that Arbiter will read data from, you can only use the type that Arbiter can support. Support metric-server and prometheus for now.
3. metric under spec, it's the data collection policy from the source.

property	Usage	Default value
historyLimit	The maximum limit of history data that will be saved	1
metricIntervalSeconds	Time interval to retrieve data from source	30
timeRangeSeconds	Time range to keep the latest data	3600
metrics	The metrics that will be used to query the source, it contains metric name, query languange, unit, aggregations and description	3600

4. targetRef under spec, it's used to get some metadata from the target resource and use the values in the query

property	Usage	Default value
group	API group of to match with target resource	''
index	The index of the data to be saved to this OBI, in case there are multiple objects matched	0
kind	Kind to match with target resource	''
labels	Labels to match with target resource	''
name	Name to match with target resource	''
namespace	Namespace to match with target resource	''
version	API version to match with the target resource	'v1'

5. status is also the default for Kubernetes resources, it show the current data collected from source using specified query. metrics will have the data and timestamp collected.