KubePattern Pattern as Code

What is Pattern-as-Code?

Pattern-as-Code (PaC) is a Kubernetes Custom Resource Definition (CRD) that allows you to define metrics and patterns to recognize Kubernetes resources that deviate from architectural principles and best practices. They also are comprehensive of a remediation reverence documentation and a severity level to prioritize the most critical issues.

API Documentation

The API allows you to write rules to identify Smells and their remediation strategies within the Kubernetes Cluster.

API version

Current Pattern as Code api version: v1

Pattern Definition Structure

Root Level Properties

Property	Type	Required	Description
`apiVersion`	string	Yes	API version of the Pattern CRD (e.g., `kubepattern.dev/v1`)
`kind`	string	Yes	Always `Pattern`
`metadata`	object	Yes	Standard Kubernetes metadata (name, namespace, labels, annotations)
`spec`	object	Yes	Core specification of the pattern, containing detection logic and relationships

`metadata`

Property	Type	Required	Description
`name`	string	Yes	Unique name of the pattern regex: `^[a-z0-9]([-a-z0-9]*[a-z0-9])?$` (e.g., `my-pattern`)

`spec`

Property	Type	Required	Description
`displayName`	string	Yes	Human-readable name for the pattern (e.g., `My Pattern`)
`severity`	enum	Yes	Severity level: `LOW`, `MEDIUM`, `HIGH`, `CRITICAL`
`category`	string	No	Custom category for organizational purposes (e.g., `architecture`, `security`, `cost`)
`message`	string	No	Custom message template for detected Smells (supports placeholders)
reference`	string	No	URL to documentation or remediation guide for the detected Smell
`target`	object	Yes	Definition of the primary resource to analyze
`dependencies`	array	No	List of additional resources that interact with the target
`relationships`	object	No	Definition of relationships between the target and dependent resources

`target`

Property	Type	Required	Description
`kind`	string	Yes	Kubernetes resource kind (e.g., `Pod`, `Deployment`)
`apiVersion`	string	Yes	API version of the resource (e.g., `apps/v1`)
`plural`	string	Yes	Plural name of the resource (e.g., `pods`, `deployments`)
`filters`	object	No	Criteria to narrow down the target resources (e.g., namespace, labels)

`dependencies`

Property	Type	Required	Description
`id`	string	Yes	Unique identifier for the dependency (e.g., `database`)
`kind`	string	Yes	Kubernetes resource kind of the dependency (e.g., `Service`)
`apiVersion`	string	Yes	API version of the dependency resource (e.g., `v1`)
`plural`	string	Yes	Plural name of the dependency resource (e.g., `services`)
`filters`	object	No	Criteria to narrow down the dependency resources (e.g., namespace, labels)

`target/dependencies.filters`

Property	Type	Required	Description
`matchAll`	array	No	List of filter conditions that must all be satisfied
`matchAny`	array	No	List of filter conditions where at least one must be satisfied
`matchNone`	array	No	List of filter conditions that must not be satisfied

`target/dependencies.filters.matchAll/matchAny/matchNone`

Property	Type	Required	Description
`path`	string	Yes	JSONPath to the field to evaluate (e.g., `metadata.namespace`)
`operator`	enum	Yes	Comparison operator (e.g., `EQUALS`, `CONTAINS`)
`values`	array	Yes	List of values to compare against (e.g., `["default", "production"]`)

`relationships`

Property	Type	Required	Description
`matchAll`	array	No	List of relationship criteria that must all be satisfied
`matchAny`	array	No	List of relationship criteria where at least one must be satisfied
`matchNone`	array	No	List of relationship criteria that must not be satisfied

`relationships.matchAll/matchAny/matchNone`

Property	Type	Required	Description
`with`	string	Yes	Identifier of the dependency to evaluate the relationship against (e.g., `database`)
`type`	enum	Yes	Type of relationship to evaluate: `custom`, `owns`, `ownedBy`
`criteria`	array	No	List of criteria to evaluate the relationship (custom logic based on resource fields)

`relationships.matchAll/matchAny/matchNone.criteria` (if `type` is `custom`)

Property	Type	Required	Description
`targetPath`	string	Yes	JSONPath to the field in the target resource to evaluate (e.g., `metadata.name`)
`dependencyPath`	string	Yes	JSONPath to the field in the dependency resource to evaluate (e.g., `metadata.name`)
`operator`	enum	Yes	Comparison operator (e.g., `EQUALS`, `CONTAINS`)

Operators Reference

Filter Operators

Operator	Description
`EQUALS`	Checks if the field value is equal to any of the specified values
`IS_EMPTY`	Checks if the field value is empty or not defined
`EXISTS`	Checks if the field exists in the resource
`GREATER_THAN`	Checks if the field value is greater than the specified value (numeric comparison)
`GREATER_OR_EQUAL`	Checks if the field value is greater than or equal to the specified value (numeric comparison)
`LESS_THAN`	Checks if the field value is less than the specified value (numeric comparison)
`LESS_OR_EQUAL`	Checks if the field value is less than or equal to the specified value (numeric comparison)
`ARRAY_SIZE_EQUALS`	Checks if the size of the array field is equal to the specified value
`ARRAY_SIZE_GREATER_THAN`	Checks if the size of the array field is greater than the specified value
`ARRAY_SIZE_GREATER_OR_EQUAL`	Checks if the size of the array field is greater than or equal to the specified value
`ARRAY_SIZE_LESS_THAN`	Checks if the size of the array field is less than the specified value
`ARRAY_SIZE_LESS_OR_EQUAL`	Checks if the size of the array field is less than or equal to the specified value

Criteria Operators (for custom relationships)

Operator	Description
`EQUALS`	Checks if the value at `targetPath` is equal to the value at `dependencyPath`

Example Pattern-as-Code Definition

apiVersion: kubepattern.dev/v1
kind: Pattern
metadata:
  name: page-not-referenced
spec:
  message: "Page {{target.metadata.name}} in namespace {{target.metadata.namespace}} is not managed by any NavMenuItem."
  displayName: Page Not Referenced
  category: Architecture
  severity: HIGH
  target:
    kind: Page
    apiVersion: widgets.templates.krateo.io/v1beta1
    plural: pages
    filters:
      matchNone:
        - path: "metadata.namespace"
          operator: EQUALS
          values:
            - krateo-system

  dependencies:
    - id: navmenuitem
      kind: NavMenuItem
      apiVersion: widgets.templates.krateo.io/v1beta1
      plural: navmenuitems

  relationships:
    matchNone:
      - with: navmenuitem
        type: custom
        criteria:
          - targetPath: "metadata.name"
            dependencyPath: "spec.resourcesRefs.items[*].name"
            operator: EQUALS
          - targetPath: "metadata.namespace"
            dependencyPath: "spec.resourcesRefs.items[*].namespace"
            operator: EQUALS

---
apiVersion: kubepattern.dev/v1
kind: Pattern
metadata:
  name: paragraph-not-referenced
spec:
  message: "Paragraph {{target.metadata.name}} in namespace {{target.metadata.namespace}} is not managed by any widgets."
  displayName: Paragraph Not Referenced
  category: Architecture
  severity: HIGH
  target:
    kind: Paragraph
    apiVersion: widgets.templates.krateo.io/v1beta1
    plural: paragraphs
    filters:
      matchNone:
        - path: "metadata.namespace"
          operator: EQUALS
          values:
            - krateo-system

  dependencies:
    - id: panel
      kind: Panel
      apiVersion: widgets.templates.krateo.io/v1beta1
      plural: panels
    - id: column
      kind: Column
      apiVersion: widgets.templates.krateo.io/v1beta1
      plural: columns
    - id: row
      kind: Row
      apiVersion: widgets.templates.krateo.io/v1beta1
      plural: rows

  relationships:
    matchNone:
      - with: panel
        type: custom
        criteria:
          - targetPath: "metadata.name"
            dependencyPath: "spec.resourcesRefs.items[*].name"
            operator: EQUALS
          - targetPath: "metadata.namespace"
            dependencyPath: "spec.resourcesRefs.items[*].namespace"
            operator: EQUALS
      - with: column
        type: custom
        criteria:
          - targetPath: "metadata.name"
            dependencyPath: "spec.resourcesRefs.items[*].name"
            operator: EQUALS
          - targetPath: "metadata.namespace"
            dependencyPath: "spec.resourcesRefs.items[*].namespace"
            operator: EQUALS
      - with: row
        type: custom
        criteria:
          - targetPath: "metadata.name"
            dependencyPath: "spec.resourcesRefs.items[*].name"
            operator: EQUALS
          - targetPath: "metadata.namespace"
            dependencyPath: "spec.resourcesRefs.items[*].namespace"
            operator: EQUALS

What is Pattern-as-Code?​

API Documentation

API version​

Pattern Definition Structure​

Root Level Properties​

metadata​

spec​

target​

dependencies​

target/dependencies.filters​

target/dependencies.filters.matchAll/matchAny/matchNone​

relationships​

relationships.matchAll/matchAny/matchNone​

relationships.matchAll/matchAny/matchNone.criteria (if type is custom)​

Operators Reference​

Filter Operators​

Criteria Operators (for custom relationships)​