Installation

License: Dual-license

Using Backstage plugin version 1.0.0?

We introduced some breaking changes in the plugin, and the ways you map your resources to EventCatalog resources.

We recommend using the latest version of the plugin. You can read the migration guide to help you upgrade.

---

Configuring your EventCatalog for Backstage

You will need a license key to use the backstage integration, this is either the SCALE license key or the Backstage license key.

You can get a 14 day trial license key from EventCatalog Cloud.

Once you have a license key for Backstage, you will need to build and deploy your EventCatalog with the license key set.

1. Setting license key in .env file (recommended)

Added in eventcatalog@2.35.4

Create a .env file in the root of your project and add the following:

.env

# If you have a Backstage license key
EVENTCATALOG_LICENSE_KEY_BACKSTAGE=your-license-key

# If you have a SCALE license key
EVENTCATALOG_SCALE_LICENSE_KEY=your-scale-license-key

Using an older version of EventCatalog?

If you are using an older version of EventCatalog that does not support the .env file, you can just export the license key as an environment variable.

Setting license key in environment variables

# If you have a Backstage license key
export EVENTCATALOG_LICENSE_KEY_BACKSTAGE=your-license-key

# If you have a SCALE license key
export EVENTCATALOG_SCALE_LICENSE_KEY=your-scale-license-key

This will enable you to use EventCatalog within backstage.

Configuring Backstage to use EventCatalog

1. Install the plugin on Backstage

yarn add @eventcatalog/backstage-plugin-eventcatalog

2. Add the EventCatalog URL to the app-config.yaml

The EventCatalog plugin needs to know the URL of your EventCatalog instance. This can be set in the app-config.yaml file.

eventcatalog:
  URL: "https://demo.eventcatalog.dev"

3. Mapping Backstage resources to EventCatalog resources with annotations

Backstage and EventCatalog have different ways to create resources. For example backstage supports components, APIS, domains, systems etc, and EventCatalog supports resources (domains, services and messages (queries, commands and events)).

When you configure the plugin you need to map Backstage information to EventCatalog information, so the plugin knows which EventCatalog page to render.

We do this by adding annotations to the Backstage resources.

Annotation	Required	Default	Description
eventcatalog.dev/id	Yes	-	The id of the resource in EventCatalog
eventcatalog.dev/version	No	latest	The version of the resource in EventCatalog
eventcatalog.dev/collection	No	Uses the entity kind	The collection of the resource in EventCatalog. Options include services, domains, queries, commands, events

Example of creating a new service in Backstage and mapping it to an EventCatalog resource:

apiVersion: backstage.io/v1alpha1
kind: Component
metadata:
  name: backend-service
  description: Backend API service
  annotations:
    github.com/project-slug: organization/backend-repo
    # Here we map the Backstage service to an EventCatalog resource
    # The id of the resource in EventCatalog
    eventcatalog.dev/id: InventoryService
    # The version of the resource in EventCatalog
    eventcatalog.dev/version: 0.0.2
    # The collection of the resource in EventCatalog
    eventcatalog.dev/collection: services
  tags:
    - nodejs
    - express
    - api
spec:
  type: service
  lifecycle: production
  owner: team-name
  system: example-system
  providesApis:
    - backend-api
  dependsOn:
    - resource:default/database

4. Using the components

Assumes a new Backstage installation, install guides my vary.

Tabbed pages

import { EventCatalogDocumentationEntityPage } from "@eventcatalog/backstage-plugin-eventcatalog";

The EventCatalogDocumentationEntityPage components, is a full page component that you can assign to any EntityLayout.Route.

// Will create a new tab called "Docs" and route called /eventcatalog. This will embed the docs for that
// entity in your page. Using the info from the app-config to map your Backstage ID to EventCatalog ID
<EntityLayout.Route path="/eventcatlaog" title="Docs">
  <EventCatalogDocumentationEntityPage page='docs' />
</EntityLayout.Route>

// Will create a new tab called "Visualzer" and route called /eventcatalog-visualizer.
// This will embed the EventCatalog visualiser to your Backstage entity
<EntityLayout.Route path="/eventcatlaog-visualizer" title="Visualzer">
  <EventCatalogDocumentationEntityPage page='visualiser' />
</EntityLayout.Route>

Card components

These components can be added to your pages as Cards, that can live inside the Backstage Grid System.

import {
  EventCatalogEntityVisualiserCard,
  EventCatalogEntityMessageCard,
} from "@eventcatalog/backstage-plugin-eventcatalog";

<Grid container spacing={3} alignItems="stretch">
  <Grid item md={6}>
    <!-- Backstage card -->
    <EntityAboutCard variant="gridItem" />
  </Grid>
  <Grid item md={6}>
    <!-- Adds the visualizer to a grid item in Backstage -->
    <EventCatalogEntityVisualiserCard />
  </Grid>
  <Grid item md={6} xs={12}>
    <!-- Adds the explore (messages) to a grid item in Backstage -->
    <EventCatalogEntityMessageCard />
  </Grid>
</Grid>;

---

Migrating from < 1.0.0

We introduced some breaking changes in the plugin, and the ways you map your resources to EventCatalog resources.

Previously you mapped your resources to EventCatalog resources in the app-config.yaml file.

eventcatalog:
  services:
    - backstage-name: "backend-service"
      eventcatalog-id: "InventoryService"

Now you have to use annotations to map your resources to EventCatalog resources.

apiVersion: backstage.io/v1alpha1
kind: Component
metadata:
  name: backend-service
  annotations:
    eventcatalog.dev/id: "InventoryService"
    eventcatalog.dev/version: "0.0.2"
    eventcatalog.dev/collection: "services"

This are the preferred ways to map your resources to EventCatalog resources and following Backstage best practices.

Demo

If you want to learn how the code works in a basic demo you can see our demo on GitHub.