Dependencies

In Cortex, you have the ability to define outgoing dependencies on other entities. Cortex can also automatically discover dependencies for some integrations. Having dependencies defined powers the ability to notify owners when a dependency deprecates its API or makes backwards incompatible changes, and the ability to visualize dependencies in a relationship graph.

Incoming dependencies are inferred based the outgoing dependency definitions.

Visualize dependencies in the relationship graph

In Cortex, you can visualize dependencies using the relationship graph at Tools > Relationship graphs. See the Relationship graph documentation for more information.

Automated dependency notifications

When a dependency deprecates its API or makes backwards incompatible changes, Cortex surfaces these issues via these methods:

• Breaking API changes are listed in your Cortex workspace under Settings > Breaking API changes.
• Cortex attempts to automatically make comments on PRs containing breaking OpenAPI changes that have downstream dependencies that Cortex knows about.
• If a breaking change is merged to the default branch, Cortex alerts dependency owners via Slack that a breaking change was merged.

Discovery

Cortex can automatically discover dependencies from your integrations:

• AWS
• Azure Resources
• Datadog
• Dynatrace
• Google Cloud
• New Relic

How to define dependencies

You can define dependencies manually via an entity's YAML descriptor, via the Cortex UI (if UI editing is enabled), or via the API.

Your user or API key need the Edit entities permission.

Cortex UI

To define dependencies in the Cortex UI:

1. Navigate to the entity where you need to define a dependency.
2. In the upper right corner of the entity details page, click Configure entity.
3. In the entity's left sidebar, click Dependencies.
4. Click Add dependencies next to services or resources.
5. In the form, select an entity to add as a dependency.
6. Optionally, select an endpoint.
   • In order for an endpoint to populate in this dropdown, it must first be defined as a path in the entity's YAML file. See "Set an endpoint for a dependency" below.
7. Click Save dependency.

Set an endpoint for a dependency

Before you can select an endpoint from the dropdown when manually defining a dependency, that endpoint must be defined as a path in the entity's YAML file. See the example below:

openapi: 3.0.1
info:
  title: Endpoint Example Service
  description: "This is an example"
  x-cortex-tag: endpoint-example-service
  x-cortex-type: service
paths:
  /hello/world:
    get:
      description: Some description
      requestBody:
        description: optional
      responses:
        "200":
          description: optional
      deprecated: false
  /this/also/works:
    put:
      deprecated: false

In the UI, the paths will appear in the Endpoint dropdown:

Entity descriptor

The x-cortex-dependency field allows you to define a list of outgoing dependencies. A dependency should be directed towards an outgoing service or resource, or more granularly, to a specific endpoint of that entity.

info:
  x-cortex-dependency:
    - tag: braavos
      method: GET
      path: /2.0/users/{username}
      description: ensure user has payment information configured
      metadata:
        tags:
          - billing
          - identity
        prod: true

Field	Description	Optional?
tag	The tag of the entity this entity depends on, i.e. the callee. See x-cortex-tag	No
method	HTTP method if depending on a specific endpoint	Required if path is present
path	The actual endpoint this dependency refers to	Required if method is present
description	A description of the dependency.	Yes
metadata	JSON metadata tags for the relationship. Supports arbitrary objects.	Yes

API

See API Docs for authentication details.

YAML is the source of truth

If a dependency has already been set through the cortex.yaml, the API will return an error.

endpoints are optional

A dependency optionally references an endpoint (method and path) of the callee, and this must already be defined in the callee's cortex.yaml within the paths field. If no endpoint is referenced it is assumed that the caller depends on all endpoints of the callee.

For all requests method or path are optional, however if one is present the other must also be present.

When interacting with an existing dependency, the method and path must be specified correctly to identify it.

Field	Description	Optional?
callerTag	The tag of the caller.	No
calleeTag	The tag the caller depends on.	No
method	HTTP method if depending on a specific endpoint	Required if path is present
path	The actual endpoint (as defined in the OpenAPI file) the caller depends on	Required if method is present
description	A description of the dependency.	Yes
metadata	JSON metadata tags for the relationship. Supports arbitrary objects.	Yes

{
  "callerTag": "my-service",
  "calleeTag": "braavos",
  "path": "/2.0/users/{username}",
  "method": "GET",
  "description": "ensure user has payment information configured",
  "metadata": {
    "tags": ["billing", "identity"],
    "prod": true
  }
}

Create a dependency

POST /api/v1/catalog/{caller-tag}/dependencies/{callee-tag}?method={method}&path={path}

{
  "description": "ensure user has payment information configured",
  "metadata": {
    "tags": ["billing", "identity"],
    "prod": true
  }
}

Retrieve a dependency

GET /api/v1/catalog/{caller-tag}/dependencies/{callee-tag}?method={method}&path={path}

Update a dependency

PUT /api/v1/catalog/{caller-tag}/dependencies/{callee-tag}?method={method}&path={path}

PUT replaces entire object

The request body is considered a modified version of the already existing entity. Leaving a field out of the JSON will be interpreted as null.

{
  "description": "ensure user has payment information configured",
  "metadata": {
    "tags": ["billing", "identity"],
    "prod": false
  }
}

Delete a dependency

DELETE /api/v1/catalog/{caller-tag}/dependencies/{callee-tag}?method={method}&path={path}

Bulk create or update dependencies

PUT /api/v1/catalog/dependencies

PUT replaces entire object

The request body is considered a modified version of the already existing entity. Leaving a field out of the JSON will be interpreted as null.

{
  "values": {
    "my-service": [
      {
        "tag": "braavos",
        "path": "/2.0/users/{username}",
        "method": "GET",
        "description": "ensure user has payment information configured",
        "metadata": {
          "tags": ["billing", "identity"],
          "prod": true
        }
      }
    ],
    "my-other-service": [
      {
        "tag": "my-service",
        "path": "/1.0/widget/{id}",
        "method": "GET",
        "description": "get widget",
        "metadata": {
          "tags": ["widget"],
          "prod": true
        }
      }
    ]
  }
}

Sync dependencies

Cortex syncs dependencies every day at 12:00 a.m. UTC.

If you need to sync dependencies manually:

1. Navigate to Tools > Relationship graphs.
2. Click Sync dependencies at the top of the page.