Event Rule Engine

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Introduction

Event Rule Engine is an rule script evaluating engine for KubeSphere event processing. It can run expression calculation on json members.

Supported grammer

Boolean calculation

Operation supported: and, or, not, =, !=

Variables contain json boolean member can calculate directly.

Examples
open and involvedObject.apiVersion="v1"
!open
open = true
open != true

The bool value suport three formates, TRUE True true

Number comparision

Operation supported: =, !=, >, <, >=, <=, in, not in

Data type supported: int, long, float, double

Examples
count >= 20

String comparision

Operation supported: =, !=, >, <, >=, <=, in, not in, contains, not contains

Examples
metadata.namespace = "kube-system"
metadata.namespace in ("kube-system", "default")
metadata.namespace contains "system"

Regular comparision

Operation supported: like, not like, regex, not regex

Examples
metadata.namespace like "ks*"
metadata.name like "redis-?"
metadata.namespace in ("kube-system", "default")
metadata.namespace contains "system"

Use '*' to substitute any string, use '?' to substitute a character。 Regexp, not regexp operation only suport standard regular syntax.

Array comparision

Operation supported: all

Examples
ResponseObject.status.images[28].names[0].names = "redis"

You can use '*' to substitute the index of array, this means if any element of the array match the right value, then expression holds。 You can use "start:end" such as "1:5" to specify a subset of th array. You can omitted either the start index or the end index, it means the subset start at the begining of array, or end at the ending of array.

Complex examples

Examples
(metadata.namespace in ("kube-system", "default") or count >= 20) and involvedObject.apiVersion contains "v1"