remove redundant endpoint to get workers in cluster (#2240)

### Motivation

There are two endpoints to do the same thing for worker functions which is get a list of workers

### Modifications

Remove one of the redundant endpoints

pulsar-broker/src/main/java/org/apache/pulsar/broker/admin/impl/FunctionsBase.java

@@ -209,7 +209,8 @@ public Response listFunctions(final @PathParam("tenant") String tenant,
 
     })
     @Path("/cluster")
-    public Response getCluster() {
+    @Produces(MediaType.APPLICATION_JSON)
+    public List<WorkerInfo> getCluster() {
         return functions.getCluster();
     }
 
@@ -302,14 +303,4 @@ public Response downloadFunction(final @QueryParam("path") String path) {
     public List<ConnectorDefinition> getConnectorsList() throws IOException {
         return functions.getListOfConnectors();
     }
-
-    @GET
-    @Path("/workers")
-    @ApiOperation(value = "Get all current member workers.")
-    @Produces(MediaType.APPLICATION_JSON)
-    @Consumes(MediaType.APPLICATION_JSON)
-    public List<WorkerInfo> getWorkers() {
-        return functions.getWorkers();
-    }
-
 }

pulsar-broker/src/test/java/org/apache/pulsar/io/PulsarFunctionAdminTest.java

@@ -212,7 +212,7 @@ private WorkerService createPulsarFunctionWorker(ServiceConfiguration config) {
 
     @Test
     public void testGetWokersApi() throws Exception {
-        List<WorkerInfo> workers = admin.functions().getWorkers();
+        List<WorkerInfo> workers = admin.functions().getCluster();
         Assert.assertEquals(workers.size(), 1);
         Assert.assertEquals(workers.get(0).getPort(), workerServicePort);
     }

pulsar-client-admin/src/main/java/org/apache/pulsar/client/admin/Functions.java

@@ -258,5 +258,5 @@ public interface Functions {
      * @return
      * @throws PulsarAdminException 
      */
-    List<WorkerInfo> getWorkers() throws PulsarAdminException;
+    List<WorkerInfo> getCluster() throws PulsarAdminException;
 }

pulsar-client-admin/src/main/java/org/apache/pulsar/client/admin/internal/FunctionsImpl.java

@@ -273,9 +273,9 @@ public Set<String> getSinks() throws PulsarAdminException {
                 .map(ConnectorDefinition::getName).collect(Collectors.toSet());
     }
 
-    public List<WorkerInfo> getWorkers() throws PulsarAdminException {
+    public List<WorkerInfo> getCluster() throws PulsarAdminException {
         try {
-            return request(functions.path("workers")).get(new GenericType<List<WorkerInfo>>() {
+            return request(functions.path("cluster")).get(new GenericType<List<WorkerInfo>>() {
             });
         } catch (Exception e) {
             throw getApiException(e);

pulsar-client-tools/src/main/java/org/apache/pulsar/admin/cli/CmdFunctions.java

@@ -107,7 +107,7 @@ public class CmdFunctions extends CmdBase {
     private final TriggerFunction triggerer;
     private final UploadFunction uploader;
     private final DownloadFunction downloader;
-    private final GetWorkers workers;
+    private final GetCluster cluster;
 
     /**
      * Base command
@@ -888,11 +888,11 @@ void runCmd() throws Exception {
         }
     }
 
-    @Parameters(commandDescription = "Get list of workers registered into cluster")
-    class GetWorkers extends BaseCommand {
+    @Parameters(commandDescription = "Get list of workers registered in cluster")
+    class GetCluster extends BaseCommand {
         @Override
         void runCmd() throws Exception {
-            String json = (new Gson()).toJson(admin.functions().getWorkers());
+            String json = (new Gson()).toJson(admin.functions().getCluster());
             Gson gson = new GsonBuilder().setPrettyPrinting().create();
             System.out.println(gson.toJson(new JsonParser().parse(json)));
         }
@@ -911,7 +911,7 @@ public CmdFunctions(PulsarAdmin admin) throws PulsarClientException {
         triggerer = new TriggerFunction();
         uploader = new UploadFunction();
         downloader = new DownloadFunction();
-        workers = new GetWorkers();
+        cluster = new GetCluster();
         jcommander.addCommand("localrun", getLocalRunner());
         jcommander.addCommand("create", getCreater());
         jcommander.addCommand("delete", getDeleter());
@@ -923,7 +923,7 @@ public CmdFunctions(PulsarAdmin admin) throws PulsarClientException {
         jcommander.addCommand("trigger", getTriggerer());
         jcommander.addCommand("upload", getUploader());
         jcommander.addCommand("download", getDownloader());
-        jcommander.addCommand("workers", workers);
+        jcommander.addCommand("cluster", cluster);
     }
 
     @VisibleForTesting

pulsar-functions/worker/src/main/java/org/apache/pulsar/functions/worker/rest/api/FunctionsImpl.java

@@ -488,7 +488,7 @@ public List<ConnectorDefinition> getListOfConnectors() {
         return this.worker().getConnectorsManager().getConnectors();
     }
 
-    public List<WorkerInfo> getWorkers() {
+    public List<WorkerInfo> getCluster() {
         if (!isWorkerServiceAvailable()) {
             throw new WebApplicationException(
                     Response.status(Status.SERVICE_UNAVAILABLE).type(MediaType.APPLICATION_JSON)
@@ -497,17 +497,6 @@ public List<WorkerInfo> getWorkers() {
         return worker().getMembershipManager().getCurrentMembership();
     }
 
-    public Response getCluster() {
-
-        if (!isWorkerServiceAvailable()) {
-            return getUnavailableResponse();
-        }
-
-        MembershipManager membershipManager = worker().getMembershipManager();
-        List<WorkerInfo> members = membershipManager.getCurrentMembership();
-        return Response.status(Status.OK).entity(new Gson().toJson(members)).build();
-    }
-
     public WorkerInfo getClusterLeader() {
         if (!isWorkerServiceAvailable()) {
             throw new WebApplicationException(

pulsar-functions/worker/src/main/java/org/apache/pulsar/functions/worker/rest/api/v2/FunctionApiV2Resource.java

@@ -131,7 +131,9 @@ public Response listFunctions(final @PathParam("tenant") String tenant,
 
     @GET
     @Path("/cluster")
-    public Response getCluster() {
+    @Produces(MediaType.APPLICATION_JSON)
+    @ApiOperation(value = "Fetches information about the Pulsar cluster running Pulsar Functions")
+    public List<WorkerInfo> getCluster() {
         return functions.getCluster();
     }
 
@@ -179,14 +181,4 @@ public Response downloadFunction(final @QueryParam("path") String path) {
     public List<ConnectorDefinition> getConnectorsList() throws IOException {
         return functions.getListOfConnectors();
     }
-
-    @GET
-    @Path("/workers")
-    @ApiOperation(value = "Get all current member workers.")
-    @Produces(MediaType.APPLICATION_JSON)
-    @Consumes(MediaType.APPLICATION_JSON)
-    public List<WorkerInfo> getWorkers() {
-        return functions.getWorkers();
-    }
-
 }