ATLAS-5377: Remove duplicate NotificationREST endpoint from webapp

[UmeshPatil-1]

What changes were proposed in this pull request?

This PR implements ATLAS-5377: consolidate hook REST notification ingress on rest-notification-webapp and remove the duplicate endpoint from the main Atlas webapp.

Background

Previously, hooks could POST notification messages to two URLs:

Endpoint	URL
Main webapp (duplicate)	POST http://<host>:21000/api/atlas/v2/notification/topic/{topicName}
REST notification server (canonical)	POST http://<host>:41000/rest/api/atlas/v2/notification/topic/{topicName}

This PR removes the duplicate ingress on port 21000 and ensures hook clients target 41000/rest only.

Changes

1. Remove duplicate endpoint from main webapp

• Deleted webapp/src/main/java/org/apache/atlas/web/rest/NotificationREST.java
• Hook POST to :21000/api/atlas/v2/notification/topic/{topicName} is no longer served
• Canonical endpoint remains in rest-notification-webapp (unchanged)

2. RestNotification client fail-fast

• Modified notification/src/main/java/org/apache/atlas/notification/rest/RestNotification.java
• Removed silent fallbacks to:
  • atlas.rest.address (main webapp, port 21000)
  • DEFAULT_ATLAS_URL (http://localhost:31000/)
• If atlas.hook.rest.notification.address is not configured when REST notification is enabled, throws AtlasException at startup with an actionable message
• Uses AtlasConfiguration.NOTIFICATION_HOOK_REST_ADDRESS.getPropertyName() instead of a hardcoded property string

3. AtlasConstants

• Added DEFAULT_REST_NOTIFICATION_ADDRESS = "http://localhost:41000/rest" for error-message guidance
• Retained DEFAULT_ATLAS_REST_ADDRESS = "http://localhost:21000" for the main metadata REST API (unchanged purpose)

4. Unit tests

• Updated notification/src/test/java/org/apache/atlas/notification/RestNotificationTest.java
• Replaced fallback tests with fail-fast tests (missing address, blank address, only atlas.rest.address configured)
• Added test for exception message content

Breaking change / migration

Operators using REST hook mode must configure:

atlas.hook.rest.notification.enabled=true
atlas.hook.rest.notification.address=http://<rest-host>:41000/rest
atlas.rest.basic.auth.username=<user>
atlas.rest.basic.auth.password=<password>

---

How was this patch tested?

Unit tests

mvn clean install -DskipITs=false -Dcheckstyle.skip=false -Drat.skip=true
mvn -pl common install -DskipTests -Drat.skip=true
mvn -pl notification test -Dtest=RestNotificationTest -Drat.skip=true

Result: Tests run: Failures: 0, Errors: 0, Skipped: 0 — BUILD SUCCESS

Manual tests (local distro)

Test	Command / check	Expected	Result
REST canonical POST	curl -u admin:admin -X POST .../41000/rest/.../ATLAS_HOOK	HTTP 204	PASS
Main webapp POST removed	curl -u admin:admin -X POST .../21000/api/.../ATLAS_HOOK	Endpoint gone (HTTP 500 + NotFoundException in application.log)	PASS
Main Atlas health	curl -u admin:admin .../21000/api/atlas/v2/types/typedefs	HTTP 200	PASS
REST server health	curl .../41000/rest/api/atlas/admin/status	HTTP 200	PASS
Authorization	curl -u rangertagsync:rangertagsync -X POST .../41000/rest/.../ATLAS_HOOK	HTTP 403	PASS

---

References

• ATLAS-4335, ATLAS-5207 (rest-notification-webapp infrastructure)

---

UI changes

None — no UI changes in this PR.

[chaitalicod]

@UmeshPatil-1 Did you check this on docker ?

[UmeshPatil-1]

@UmeshPatil-1 Did you check this on docker ?

yes