Adding custom data

Custom data extends the out-of-the-box metadata that Cortex provides via integrations, enhancing your use of catalogs and augmenting details available for your entities. This data can also be used to write CQL queries and Scorecard rules.

Custom data can be defined manually in the entity descriptor, added to entities programmatically via a REST API, or sent through a webhook. To learn about sending data via webhook, see Custom webhook integrations.

Defining custom data

There are a few ways you can add custom data to an entity:

• In the entity descriptor

  • This is optimal for low-volume, human-maintained data because it requires updating the entity's YAML when the data changes.

• Via a POST REST API endpoint

  • Using a REST API is a better option for data that comes from an automated process, like a CI/CD pipeline.

• A webhook.

  • This can be done without auth or an explicit entity tag in the URL if you do not have access to the entity tag or the ability to add authentication headers.

Entity descriptor

Editing the entity descriptor

Learn more about entity YAML descriptors in the Managing entities documentation.

The simplest way to describe information in the YAML is to define an object.

x-cortex-custom-metadata:
  key-example: value-example
  arbitrary-custom-data: hippocampus
  regions-of-brain:
    value: 3
    description: cerebrum, cerebellum, brainstem
  cognition: true

Field	Description	Required
key	Key or title for the custom data. Anything defined before the : will serve as the key.	✓
value	Value for the custom data. Anything defined after the : is the value.	✓

Custom data can be of any type, including scalars (strings, numbers, booleans), objects, and lists.

When you add custom data to an entity's YAML, you'll see the key and value pairs on an entity's Custom data page.

Custom data added via entity descriptor will display with a YAML tag.

Adding descriptions

You can add a description to data by explicitly defining it along with the key and value pairs. While key and value pairs can be defined with any terms when a description is not added, value: must explicitly be defined when a description is included.

x-cortex-custom-metadata:
  regions-of-brain:
    value: 3
    description: cerebrum, cerebellum, brainstem
  brain-hemispheres:
    value: 2
    description: The brain has a left and a right hemisphere.

Field	Description	Required
key	Key or title for the custom data. Anything defined before the : will serve as the key.	✓
value	Value for the key; should be defined explicitly with value:	✓
description	Description of the custom data	✓

Note: While the description field is always optional, it is technically "required" to add a description to custom data.

API

Adding custom data via the Cortex API

You can pipe custom data directly into Cortex by POSTing to /api/v1/catalog/{tag}/custom-data where {tag}is the x-cortex-tag for a given entity.

The request body requires the following in JSON format:

Field	Type	Description	Required
key	string	Key or title for the custom data	✓
value	object	Value for the custom data	✓
description	string	Description of the custom data

See the API docs for authentication details.

If a key has already been set through the entity descriptor, an API call will NOT overwrite the existing value. Instead, it will simply return the existing value.

If a key is defined in the entity descriptor, the API cannot override the key. You'll see YAML as the source value in the response body if you encounter this situation.

To explicitly overwrite values set in the YAML file, use the force=true flag as a query parameter.

If you find yourself using the force flag, it may be better to remove the field from the YAML file or update the value in the cortex.yaml file instead to maintain the source of truth.

Custom data added via API will display with a API tag.

Bulk upload entity keys

You can use the bulk upload endpoint to upload multiple keys for one or more entities.

PUT data in the following format to /api/v1/catalog/custom-data:

{
  "values": {
    "<entity-tag>": [
      {
        "key":"example-key",
        "value":"example value",
        "description":"A description of these data."
      }
    ],
    "<another-entity-tag>": [
      {
        "key":"example",
        "value":{
          "my-data":"my-value",
          "complex": "data",
          "v": 0
        }
      }
    ]
  }
}

You can include multiple key and value objects for each tag. The object conforms to the same shape as the single upload API.

Webhook

Learn more in Custom webhook integrations.

Data source hierarchy

Cortex applies a data source hierarchy to determine how to handle a case where the same key is defined from multiple sources.

• The entity descriptor is the source of truth. If a key is defined there, the API or webhooks cannot override the key.
• The API and webhook approaches are at the same level and can override each other.

You can override keys defined in the YAML by adding a force=true parameter when using an API, but when the entity descriptor is eventually re-processed, the data provided via the API will be overwritten.

Use cases

Cataloging

Catalogs contain a lot of useful metadata about entities, including ownership and data from integrations. However, you may have your own custom fields that you want to include that would make exploring the catalog easier.

These can include things like:

• Which AWS zones is this deployed in?

• What databases does the entity consume?

• When was the last successful CI run?

If the answers to these questions fit a pre-enumerated list, consider using groups. Groups are displayed on entity detail pages and can easily be applied in catalog filters.

Custom data for cataloging makes the most sense when the data is more flexible.

Custom data can then be queried against by using the Query builder, explored with CQL reports, or viewed on an entity's details page.

Scorecards

Cortex makes it easy to write Scorecard rules based on custom data that exists in your catalogs. When adding a rule, you can select Custom data from Choose an integration in the form editor and follow the flow. Cortex will automatically supply variables based on the custom data you've defined.

Using the custom data API to push data into Cortex and extend your Scorecards. You can send entire JSON payloads and use jq to process them in a Scorecard, or use it as an input to a custom OPA Policy as a Scorecard rule.