events-backend: more elaborate local development setup with multiple backends

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

plugins/events-backend/dev/index.ts

@@ -14,18 +14,60 @@
  * limitations under the License.
  */
 
+import { WinstonLogger } from '@backstage/backend-app-api';
 import { createBackend } from '@backstage/backend-defaults';
 import {
   coreServices,
   createBackendPlugin,
+  createServiceFactory,
 } from '@backstage/backend-plugin-api';
+import { mockServices } from '@backstage/backend-test-utils';
 import { eventsServiceRef } from '@backstage/plugin-events-node';
 
-const backend = createBackend();
+function makeBackend(port: number) {
+  const backend = createBackend();
 
-backend.add(import('../src/alpha'));
+  backend.add(
+    mockServices.rootConfig.factory({
+      data: {
+        backend: {
+          baseUrl: `http://localhost:${port}`,
+          listen: { port },
+          database: {
+            client: 'pg',
+            connection: {
+              host: 'localhost',
+              port: 5432,
+              user: process.env.USER || 'postgres',
+            },
+          },
+        },
+      },
+    }),
+  );
+  backend.add(
+    createServiceFactory({
+      service: coreServices.rootLogger,
+      deps: {},
+      async factory() {
+        return WinstonLogger.create({
+          meta: {
+            service: 'backstage',
+            port,
+          },
+          // level: 'debug',
+          format: WinstonLogger.colorFormat(),
+        });
+      },
+    }),
+  );
+  backend.add(import('../src/alpha'));
 
-backend.add(
+  return backend;
+}
+
+const backend7008 = makeBackend(7008);
+backend7008.add(
   createBackendPlugin({
     pluginId: 'producer',
     register(reg) {
@@ -37,19 +79,29 @@ backend.add(
         },
         async init({ events, logger, rootLifecycle }) {
           rootLifecycle.addStartupHook(async () => {
-            logger.info(`Publishing event to topic 'test'`);
-            await events.publish({
-              eventPayload: { foo: 'bar' },
-              topic: 'test',
-            });
+            const publish = () => {
+              logger.info(`Publishing event to topic 'test'`);
+              events
+                .publish({
+                  eventPayload: { foo: 'bar' },
+                  topic: 'test',
+                })
+                .catch(error => {
+                  logger.error(`Failed to publish event from producer`, error);
+                });
+            };
+            publish();
+            setInterval(publish, 10000);
           });
         },
       });
     },
   }),
 );
+backend7008.start();
 
-backend.add(
+const backend7009 = makeBackend(7009);
+backend7009.add(
   createBackendPlugin({
     pluginId: 'consumer',
     register(reg) {
@@ -60,10 +112,10 @@ backend.add(
         },
         async init({ events, logger }) {
           await events.subscribe({
-            id: 'test-1',
+            id: 'test',
             topics: ['test'],
             async onEvent(event) {
-              logger.info(`Received event: ${JSON.stringify(event, null, 2)}`);
+              logger.info(`Received event: ${JSON.stringify(event)}`);
             },
           });
         },
@@ -71,5 +123,29 @@ backend.add(
     },
   }),
 );
+backend7009.start();
 
-backend.start();
+const backend7010 = makeBackend(7010);
+backend7010.add(
+  createBackendPlugin({
+    pluginId: 'consumer',
+    register(reg) {
+      reg.registerInit({
+        deps: {
+          events: eventsServiceRef,
+          logger: coreServices.logger,
+        },
+        async init({ events, logger }) {
+          await events.subscribe({
+            id: 'test',
+            topics: ['test'],
+            async onEvent(event) {
+              logger.info(`Received event: ${JSON.stringify(event)}`);
+            },
+          });
+        },
+      });
+    },
+  }),
+);
+backend7010.start();

plugins/events-backend/package.json

@@ -67,6 +67,7 @@
     "winston": "^3.2.1"
   },
   "devDependencies": {
+    "@backstage/backend-app-api": "workspace:^",
     "@backstage/backend-defaults": "workspace:^",
     "@backstage/backend-test-utils": "workspace:^",
     "@backstage/cli": "workspace:^",

yarn.lock

@@ -6137,6 +6137,7 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "@backstage/plugin-events-backend@workspace:plugins/events-backend"
   dependencies:
+    "@backstage/backend-app-api": "workspace:^"
     "@backstage/backend-common": ^0.25.0
     "@backstage/backend-defaults": "workspace:^"
     "@backstage/backend-openapi-utils": "workspace:^"