Support custom relationships

[AvitalTamir]

Allows defining custom relationships between Kubernetes resources in a ~/.cyphernetes/relationships.yaml file. This is useful when working with custom resources or when you want to define relationships that aren't built into Cyphernetes.

Example relationships.yaml:

relationships:
  - kindA: applications.argoproj.io
    kindB: services
    relationship: ARGOAPP_SYNC_SERVICE
    matchCriteria:
      - fieldA: "$.spec.source.targetRevision"
        fieldB: "$.metadata.labels.targetRevision"
        comparisonType: ExactMatch
      - fieldA: "$.spec.project"
        fieldB: "$.metadata.labels.project" 
        comparisonType: ExactMatch

  - kindA: pods
    kindB: deployments
    relationship: DEPLOYMENT_OWN_POD
    matchCriteria:
      - fieldA: "$.metadata.name"
        fieldB: "$.metadata.name"
        comparisonType: StringContains

The relationships.yaml file supports the following fields:

• kindA, kindB: The Kubernetes resource kinds to relate (use plural form, e.g. "deployments" not "Deployment")
• relationship: A unique identifier for this relationship type (conventionally UPPERCASE)
• matchCriteria: List of criteria that must all match for the relationship to exist
  • fieldA: JSONPath to field in kindA resource
  • fieldB: JSONPath to field in kindB resource
  • comparisonType: One of:
  • ExactMatch: Values must match exactly
  • ContainsAll: All key-value pairs in fieldB must exist in fieldA
  • StringContains: The value in fieldA contains the value in fieldB as a substring
  • defaultProps: Optional default values to use when creating resources
  • fieldA: JSONPath to field in kindA
  • fieldB: JSONPath to field in kindB
  • default: Default value if field is not specified

Custom relationships are loaded on startup and can be used just like built-in relationships in queries:

MATCH (d:Deployment)->(p:Pod)
RETURN d.metadata.name, p.metadata.name