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Mirror Property

Mirror property allows you to map data from related entities to your entity. Mirror property can be used for blueprints that have relations defined.

When two blueprints are connected via a relation, a new set of properties becomes available to entities in the source blueprint.

Those new properties are called mirrorProperties.

Mirror properties will appear on the source blueprint as an additional key called mirrorProperties. It represents additional properties queried from the target blueprint (or from other entities further down the connection graph).

Mirror properties allow you to map property values from related entities, to keys in the source blueprint, thus giving you more context and data when viewing an Entity, while not cluttering the output with unnecessary fields.

Mirror properties support both user-defined properties, and meta-properties by using similar syntax.

💡 Common mirror usage​

Mirror properties make it possible to enrich the data visible on an entity by mapping additional data and properties from other related entities in the catalog, for example:

  • Show the chart version of a running service;
  • Show the environment type of a running service;
  • Show the cloud provider of a K8s cluster;
  • etc.

In this live demo example, we can see the Cloud Provider Property which is a mirror property of the related Cloud Account blueprint 🎬

API definition​

The mirrorProperties key is a top-level key in the JSON of an entity (similar to identifier, title, properties, etc..)

{
  "mirrorProperties": {
    "myMirrorProp": {
      "title": "My mirror property",
      "path": "myRelation.myProperty"
    }
  }
}

Check out Port's API reference to learn more.

info

The path key receives a path of chained relations, which lead up to a blueprint property or meta-property

Terraform definition​

resource "port_blueprint" "myBlueprint" {
  # ...blueprint properties
  mirror_properties = {
    myMirrorProp = {
      title = "My mirror property"
      path  = "myRelation.myProperty"
    }
  }
}

Pulumi definition​

"""A Python Pulumi program"""

import pulumi
from port_pulumi import Blueprint,BlueprintPropertiesArgs,BlueprintMirrorPropertiesArgs

blueprint = Blueprint(
    "myBlueprint",
    identifier="myBlueprint",
    title="My Blueprint",
    properties=BlueprintPropertiesArgs(
        # blueprint properties
    ),
    mirror_properties={
        "myMirrorProp": BlueprintMirrorPropertiesArgs(
            title="My mirror property", path="myRelation.myStringProp"
        )
    },
)

Meta-property as a mirror property​

This is a mirror property created from one of Port's meta-properties on the target blueprint.

In the following example, we create a mirror property called microserviceName which is mapped to the title meta-property in the target blueprint (in this example the name of the relation is deployment-to-microservice). Note how the title field is referenced using $title because it is a meta-property:

"microserviceName": {
    "title": "Microservice Name",
    "path": "deployment-to-microservice.$title"
}

Nested relation as a mirror property​

It is possible to use mirror properties to map properties from blueprints that are not direct descendants of our source blueprint.

For example, let's assume we have the following Relation chain: Microservice -> System -> Domain.

We want to map the members of the domain that owns the microservice directly to the Microservice entities.

The members of the domain are listed in an array property under the user-defined property domain_members.

The names of the relations are:

  • Microservice -> System: system
  • System -> Domain: domain

Let's map the squad members using a mirror property called owningDomainMembers:

"owningDomainMembers": {
    "title": "Owning Domain Members",
    "path": "system.domain.domain_members"
}