monitoring-dashboard

README

KubeSphere Monitoring Dashboard

The project is inspired by Grafana but with significant difference in data persistence, multitenancy supports and dashboard template sharing to fit KubeSphere's context. It is not a replacement to Grafana. It requires KubeSphere backend and frontend to work.

This repo is aimed at KubeSphere developers who want to understand dashboard data model, concepts and usage and how to contribute, as the custom monitoring feature is introduced as of v3.0.

Table of contents

• Get Started
  • Prerequisites
  • Quick Start
• Concept and Design
  • Data Model
  • Data Source
  • Multi-tenancy
  • Dashboard Template
• Manual
  • Query
  • Panels
  • Time Range
  • Variables
• Development
  • APIs
  • Backend
  • Frontend
• Contributing
  • Dashboard Gallery

Get Started

Prerequisites

• Kubernetes v17.0+
• KubeSphere v3.0+

Quick Start

TODO(@FeynmanZhou)

The stack making these possible includes KubeSphere backend, console and custom resources for dashboards.

• KubeSphere Backend: proxies metrics query, ensures data isolation over namespaces.
• KubeSphere Console: renders the dashboard with data and charts.
• CustomResourceDefinition for Dashboard: defines dashboard data model.

Concept and Design

Data Model

Dashboards are backed by the custom resource definition (CRD) Dashboard. It is compromised of three components: metadata, panels and templatings. Below is an example:

apiVersion: monitoring.kubesphere.io/v1alpha1
kind: Dashboard
metadata:
  name: mysql-overview
  namespace: default
spec:
  title: MySQL Overview
  description: MySQL dashboard for the mysql exporter
  time:
    from: now-1h
    to: now
  datasource: prometheus
  panels:
  - type: singlestat
    title": Instance Up
    targets:
    - expr: mysql_up{release="$release"}
      instant: "true"
  - type: graph
    title: mysql  disk reads vs writes
    targets:
    - expr": irate(mysql_global_status_innodb_data_reads{release="$release"}[10m])
      legendFormat": reads
    - expr": irate(mysql_global_status_innodb_data_writes{release="$release"}[10m])
      legendFormat": write
  templatings:
  - name: release
    query: label_values(mysql_up,release)
    type: query
    sort: 0

Metadata

Name	Desc
spec.title	dashboard title
spec.description	dashboard description
spec.time	time range for display. see Time Range for more info
spec.datasource	data source to query, defaults to Prometheus

Panels

The spec.panels defines a collection of panels. Panels are build blocks of a dashboard. Currently supported panels are row, singlestat, graph and table. See Query and Panels for more info.

Templatings

The spec.templatings defines a collection of variables. It is convenient to use variables in query expressions. See Variable for more info.

Note that the data model is heavily inspired by Grafana JSON model to gain compatibility. However, to adapt it to KubeSphere's context, we may bring in new fields and break changes.

Data Source

Note: we currently only support Prometheus as data source.

Multi-tenancy

Metrics data should be isolated across namespaces, which means namespace members can only view metrics in the namespace they belong to. This is implemented in the phase of querying. Any user-written expression will be mutated to make sure no query outside the scope of the namespace.

Take the datasource Prometheus for example, KubeSphere backend will add a namespace matcher, i.e. <metric_name>{namespace=<namespace_name>}, to each query.

Dashboard Template

Dashboard is represented by a custom resource object. Select templates from contrib/gallery, and run the following command to import:

kubectl apply --namespace <NAMESPACE> -f contrib/gallery/<TEMPLATE_YAML_FILE>

You can also open source your template and contribute to Dashboard Gallery. Templates in Dashboard Gallery will be shipped with KubeSphere.

Manual

Query

Except for the panel row, each panel accepts at least one data source query. It allows you to input query expressions and fetch metrics data.

You can use placeholders in queries. See Variables for more information.

Panels

Chart

We currently support four types of panels

• Row
• Singlestat
• Graph

Legend

Time Range

Time range specifies current dashboard time for display. The following are examples in use.

Example	From	To
Last 5 minutes	now-5m	now
Today	now-1d	now
This week	now-1w	now
Last month	now-2M	now-1M

Variables

Query	Desc
label_values(metric, label)	Returns a list of label values for the label in the specified metric.

Development

APIs

For dashboard APIs, see docs/crd.md

The project is built with kubebuilder v2.3.0.

Backend

If you find some fields should be included in the CRD, edit api package and regenerate the project by make. Kubebuilder is the tool we are using.

If you find bugs or want to add new APIs, implement new datasources to KubeSphere, read KubeSphere developer guides for monitoring.

Frontend

@TODO(justahole)

Contributing

Dashboard Gallery

If you want to share your dashboard templates, you can submit dashboard template yaml files to gallery folder with an elaborate readme. Outstanding templates will be selected to ship with KubeSphere future releases.