HTM-2016: Create a separate SseEventBus bean for the viewer so viewers don't get aministrative braodcasts

Author: mprins

README.md

@@ -217,6 +217,23 @@ mvn -Pdeveloping,postgresql verify -Dspring-boot.run.profiles=dev,populate-testd
 * You can use `mvn -U org.codehaus.mojo:versions-maven-plugin:display-dependency-updates` to search for dependency
   updates
 
+#### SSE streams
+
+We have 2 SSE streams available, one in the admin API at: `api/admin/events/{clientId}` and one in the viewer API 
+at: `api/events/{clientId}`. When using these streams you must make sure that you are using/injecting the correct
+`SseEventBus` for each API.
+
+For the admin use the default `eventBus` bean, inject using: `SseEventBus eventBus` (defined using the `@EnableSseEventBus` annotation in the `TailormapConfig` class).
+for the viewer use the `viewerSseEventBus` bean, inject using: `@Qualifier("viewerSseEventBus") SseEventBus eventBus` (defined in the `TailormapConfig` class). 
+See: 
+- [ServerSentEventsAdminController](src/main/java/org/tailormap/api/controller/admin/ServerSentEventsAdminController.java) for the admin configuration
+- [ServerSentEventsController](src/main/java/org/tailormap/api/controller/ServerSentEventsController.java) for the viewer configuration
+- [TailormapConfig](src/main/java/org/tailormap/api/configuration/TailormapConfig.java) for the bean definitions
+
+If you inject the wrong one you may not receive the events ypu want and ypu risk sending administrative events to the viewer.
+
+```
+
 ## Releasing
 
 ### Prerequisites

src/main/java/org/tailormap/api/configuration/TailormapConfig.java

@@ -5,8 +5,23 @@
  */
 package org.tailormap.api.configuration;
 
+import ch.rasc.sse.eventbus.DataObjectConverter;
+import ch.rasc.sse.eventbus.DefaultDataObjectConverter;
+import ch.rasc.sse.eventbus.DefaultSubscriptionRegistry;
+import ch.rasc.sse.eventbus.DistributedEventBus;
+import ch.rasc.sse.eventbus.JacksonDataObjectConverter;
+import ch.rasc.sse.eventbus.ReplayStore;
+import ch.rasc.sse.eventbus.SseEventBus;
+import ch.rasc.sse.eventbus.SubscriptionRegistry;
 import ch.rasc.sse.eventbus.config.EnableSseEventBus;
+import ch.rasc.sse.eventbus.config.SseEventBusConfigurer;
+import ch.rasc.sse.eventbus.observation.SseEventBusObservationConvention;
+import io.micrometer.observation.ObservationRegistry;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Locale;
+import org.jspecify.annotations.Nullable;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
@@ -15,6 +30,7 @@
 import org.springframework.scheduling.annotation.EnableScheduling;
 import org.springframework.web.servlet.LocaleResolver;
 import org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver;
+import tools.jackson.databind.ObjectMapper;
 
 @Configuration
 @EnableConfigurationProperties
@@ -42,4 +58,43 @@ public LocaleResolver localeResolver() {
     resolver.setDefaultLocale(Locale.of(defaultLanguage));
     return resolver;
   }
+
+  /**
+   * Define a ew viewer SseEventBus bean for viewer-specific SSE traffic.
+   *
+   * @return the viewerSseEventBus instance
+   */
+  @Bean("viewerSseEventBus")
+  public SseEventBus viewerSseEventBus(
+      @Autowired(required = false) @Nullable SseEventBusConfigurer configurer,
+      @Autowired(required = false) @Nullable ObjectMapper objectMapper,
+      @Autowired(required = false) @Nullable List<DataObjectConverter> dataObjectConverters,
+      @Autowired(required = false) @Nullable SubscriptionRegistry subscriptionRegistry,
+      @Autowired(required = false) @Nullable ReplayStore replayStore,
+      @Autowired(required = false) @Nullable ObservationRegistry observationRegistry,
+      @Autowired(required = false) @Nullable SseEventBusObservationConvention observationConvention,
+      @Autowired(required = false) @Nullable DistributedEventBus distributedEventBus) {
+
+    // Apply same defaults as DefaultSseEventBusConfiguration
+    SseEventBusConfigurer config = configurer != null
+        ? configurer
+        : new SseEventBusConfigurer() {
+          /* defaults */
+        };
+
+    SubscriptionRegistry registry =
+        subscriptionRegistry != null ? subscriptionRegistry : new DefaultSubscriptionRegistry();
+
+    ReplayStore store = replayStore != null ? replayStore : config.replayStore();
+
+    List<DataObjectConverter> converters = dataObjectConverters != null ? dataObjectConverters : new ArrayList<>();
+    if (objectMapper != null) {
+      converters.add(new JacksonDataObjectConverter(objectMapper));
+    } else {
+      converters.add(new DefaultDataObjectConverter());
+    }
+
+    return new SseEventBus(
+        config, registry, converters, store, observationRegistry, observationConvention, distributedEventBus);
+  }
 }

src/main/java/org/tailormap/api/controller/ServerSentEventsController.java

@@ -12,13 +12,15 @@
 import java.lang.invoke.MethodHandles;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.http.HttpStatus;
 import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.server.ResponseStatusException;
 import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;
+import org.tailormap.api.util.UUIDv7;
 import org.tailormap.api.viewer.model.ServerSentEventResponse;
 import tools.jackson.core.JacksonException;
 import tools.jackson.databind.SerializationFeature;
@@ -33,7 +35,7 @@ public class ServerSentEventsController {
 
   private final JsonMapper jsonMapper;
 
-  public ServerSentEventsController(SseEventBus eventBus, JsonMapper jsonMapper) {
+  public ServerSentEventsController(@Qualifier("viewerSseEventBus") SseEventBus eventBus, JsonMapper jsonMapper) {
     this.eventBus = eventBus;
     // force unindented/single line output for SSE messages, because we may have set
     // spring.jackson.serialization.indent_output=true for debugging/development/test
@@ -60,7 +62,9 @@ public SseEmitter sse(@PathVariable String clientId) {
 
   @Scheduled(fixedRate = 60_000)
   public void keepAlive() throws JacksonException {
-    this.eventBus.handleEvent(SseEvent.ofData(jsonMapper.writeValueAsString(
-        new ServerSentEventResponse().eventType(ServerSentEventResponse.EventTypeEnum.KEEP_ALIVE))));
+    this.eventBus.handleEvent(SseEvent.ofData(jsonMapper.writeValueAsString(new ServerSentEventResponse()
+        .eventType(ServerSentEventResponse.EventTypeEnum.KEEP_ALIVE)
+        .id(UUIDv7.randomV7())
+        .details("keep viewer alive"))));
   }
 }

src/main/java/org/tailormap/api/controller/admin/ServerSentEventsAdminController.java

@@ -21,6 +21,7 @@
 import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;
 import org.tailormap.api.admin.model.ServerSentEvent;
 import tools.jackson.core.JacksonException;
+import tools.jackson.databind.SerializationFeature;
 import tools.jackson.databind.json.JsonMapper;
 
 @RestController
@@ -34,7 +35,16 @@ public class ServerSentEventsAdminController {
 
   public ServerSentEventsAdminController(SseEventBus eventBus, JsonMapper jsonMapper) {
     this.eventBus = eventBus;
-    this.jsonMapper = jsonMapper;
+    // force unindented/single line output for SSE messages, because we may have set
+    // spring.jackson.serialization.indent_output=true for debugging/development/test
+    if (jsonMapper.isEnabled(SerializationFeature.INDENT_OUTPUT)) {
+      this.jsonMapper = jsonMapper
+          .rebuild()
+          .configure(SerializationFeature.INDENT_OUTPUT, false)
+          .build();
+    } else {
+      this.jsonMapper = jsonMapper;
+    }
   }
 
   /**

src/main/java/org/tailormap/api/service/CreateLayerExtractService.java

@@ -48,6 +48,7 @@
 import org.jspecify.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.scheduling.annotation.Scheduled;
@@ -89,7 +90,9 @@ public class CreateLayerExtractService {
   private boolean exactWfsCounts;
 
   public CreateLayerExtractService(
-      SseEventBus eventBus, JsonMapper jsonMapper, FeatureSourceFactoryHelper featureSourceFactoryHelper) {
+      @Qualifier("viewerSseEventBus") SseEventBus eventBus,
+      JsonMapper jsonMapper,
+      FeatureSourceFactoryHelper featureSourceFactoryHelper) {
     this.eventBus = eventBus;
     this.featureSourceFactoryHelper = featureSourceFactoryHelper;
     // force unindented/single line output for SSE messages, because we may have set

src/test/java/org/tailormap/api/controller/ServerSentEventsControllerIntegrationTest.java

@@ -9,8 +9,12 @@
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.request;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 import static org.tailormap.api.TestRequestProcessor.setServletPath;
 
 import java.lang.invoke.MethodHandles;
@@ -26,10 +30,13 @@
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.webmvc.test.autoconfigure.AutoConfigureMockMvc;
 import org.springframework.http.MediaType;
+import org.springframework.security.test.context.support.WithMockUser;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.MvcResult;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.context.WebApplicationContext;
 import org.tailormap.api.annotation.PostgresIntegrationTest;
-import org.tailormap.api.viewer.model.ServerSentEventResponse;
+import org.tailormap.api.persistence.Group;
 
 @PostgresIntegrationTest
 @AutoConfigureMockMvc
@@ -46,6 +53,12 @@ class ServerSentEventsControllerIntegrationTest {
   @Value("${tailormap-api.base-path}")
   private String apiBasePath;
 
+  @Value("${tailormap-api.admin.base-path}")
+  private String adminBasePath;
+
+  @Autowired
+  private WebApplicationContext context;
+
   private MvcResult sseResult;
 
   @BeforeEach
@@ -75,10 +88,72 @@ void should_send_keep_alive_messages_for_two_minutes() {
         });
   }
 
+  /** Check that at least 2 keep-alive messages arrive in 130 seconds. */
+  @Test
+  @WithMockUser(
+      username = "admin",
+      authorities = {Group.ADMIN})
+  void admin_and_viewer_should_use_separate_sse_streams() throws Exception {
+    // start admin sse stream
+    MockMvc adminMockMvc = MockMvcBuilders.webAppContextSetup(context).build();
+    final String adminSseUrl = adminBasePath + "/events/" + sseClientId;
+    MvcResult adminSseResult = adminMockMvc
+        .perform(get(adminSseUrl)
+            .accept(MediaType.TEXT_EVENT_STREAM)
+            .with(setServletPath(adminSseUrl))
+            .acceptCharset(StandardCharsets.UTF_8))
+        .andDo(print())
+        .andExpect(status().isOk())
+        .andExpect(request().asyncStarted())
+        .andReturn();
+
+    Awaitility.await("waiting at least 2 minutes for keep-alive messages")
+        .pollDelay(45, SECONDS)
+        .pollInterval(15, SECONDS)
+        .atLeast(1, MINUTES)
+        .atMost(130, SECONDS)
+        .logging(
+            logPrinter -> logger.debug("Checking for keep-alive messages in SSE streams... {}", logPrinter))
+        .untilAsserted(() -> {
+          final String adminStream = adminSseResult.getResponse().getContentAsString();
+          logger.debug("admin stream: {}", adminStream);
+          assertThat(
+              "There should be at least 2 keep-alive massages for the admin",
+              count_keep_alive_messages(adminStream),
+              greaterThanOrEqualTo(2));
+          // and
+          final String stream = sseResult.getResponse().getContentAsString();
+          logger.debug("viewer stream: {}", stream);
+          assertThat(
+              "There should be at least 2 keep-alive massages for the viewer",
+              count_keep_alive_messages(stream),
+              greaterThanOrEqualTo(2));
+          assertEquals(
+              0,
+              count_viewer_keep_alive_messages(stream),
+              "There should no keep-alive massages for the admin in the viewer");
+          assertNotEquals(
+              count_keep_alive_messages(stream),
+              count_viewer_keep_alive_messages(stream),
+              "Admin keep-alive messages should not be sent to viewer SSE stream");
+        });
+  }
+
   private int count_keep_alive_messages(String stream) {
     int count = 0;
     int index = 0;
-    final String marker = "\"eventType\":\"" + ServerSentEventResponse.EventTypeEnum.KEEP_ALIVE + "\"";
+    final String marker = "\"eventType\":\"keep-alive\"";
+    while ((index = stream.indexOf(marker, index)) != -1) {
+      count++;
+      index += marker.length();
+    }
+    return count;
+  }
+
+  private int count_viewer_keep_alive_messages(String stream) {
+    int count = 0;
+    int index = 0;
+    final String marker = "\"details\":\"keep viewer alive\",\"eventType\":\"keep-alive\"";
     while ((index = stream.indexOf(marker, index)) != -1) {
       count++;
       index += marker.length();