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mgreber pushed a commit to branch master
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The following commit(s) were added to refs/heads/master by this push:
new 18a132a9f Add /api/v1/leader endpoint to REST API endpoints
18a132a9f is described below
commit 18a132a9f377cb1ee49cf7fc84d0cda3ff781e43
Author: gabriellalotz <lotzgabrie...@gmail.com>
AuthorDate: Mon Apr 14 12:48:01 2025 +0000
Add /api/v1/leader endpoint to REST API endpoints
To support leader discovery without relying on HTTP redirects, which are
incompatible with SPNEGO authentication, a new REST API endpoint
/api/v1/leader has been introduced.
This endpoint returns the current leader master's HTTP or HTTPS address
in a compact JSON format, e.g.:
{ "leader": "http://hostname:port"; }
Change-Id: If74db14bee2d273529ebfb02e72c6675bb094bce
Reviewed-on: http://gerrit.cloudera.org:8080/22779
Tested-by: Marton Greber <greber...@gmail.com>
Reviewed-by: Marton Greber <greber...@gmail.com>
Reviewed-by: Zoltan Chovan <zcho...@cloudera.com>
---
src/kudu/master/rest_catalog-test.cc | 53 ++++++++++++++++++++++++
src/kudu/master/rest_catalog_path_handlers.cc | 58 ++++++++++++++++++++++++++-
src/kudu/master/rest_catalog_path_handlers.h | 2 +
3 files changed, 112 insertions(+), 1 deletion(-)
diff --git a/src/kudu/master/rest_catalog-test.cc
b/src/kudu/master/rest_catalog-test.cc
index 6e17ff9c7..de97544ac 100644
--- a/src/kudu/master/rest_catalog-test.cc
+++ b/src/kudu/master/rest_catalog-test.cc
@@ -16,6 +16,7 @@
// under the License.
#include <memory>
+#include <set>
#include <string>
#include <type_traits>
#include <vector>
@@ -25,6 +26,7 @@
#include "kudu/client/client.h"
#include "kudu/client/schema.h"
+#include "kudu/gutil/strings/join.h"
#include "kudu/gutil/strings/substitute.h"
#include "kudu/master/mini_master.h"
#include "kudu/master/rest_catalog_test_base.h"
@@ -44,6 +46,7 @@ using kudu::client::KuduTable;
using kudu::client::sp::shared_ptr;
using kudu::cluster::InternalMiniCluster;
using kudu::cluster::InternalMiniClusterOptions;
+using std::set;
using std::string;
using std::unique_ptr;
using std::vector;
@@ -577,5 +580,55 @@ TEST_F(RestCatalogTest, TestPutTableEndpointChangeOwner) {
ASSERT_EQ("new_owner", table->owner());
}
+class MultiMasterTest : public RestCatalogTestBase {
+ public:
+ void SetUp() override {
+ KuduTest::SetUp();
+ FLAGS_enable_rest_api = true;
+
+ InternalMiniClusterOptions opts;
+ opts.num_masters = 3;
+ cluster_.reset(new InternalMiniCluster(env_, opts));
+ ASSERT_OK(cluster_->Start());
+ KuduClientBuilder client_builder;
+ ASSERT_OK(cluster_->CreateClient(&client_builder, &client_));
+ }
+
+ protected:
+ unique_ptr<InternalMiniCluster> cluster_;
+};
+
+TEST_F(MultiMasterTest, TestGetLeaderEndpoint) {
+ set<string> leader_addresses;
+
+ static KuduRegex re("\"leader\":\"([^\"]+)\"", 1);
+
+ for (int i = 0; i < cluster_->num_masters(); i++) {
+ EasyCurl c;
+ faststring buf;
+ ASSERT_OK(c.FetchURL(Substitute("http://$0/api/v1/leader";,
+
cluster_->mini_master(i)->bound_http_addr().ToString()),
+ &buf));
+ vector<string> matches;
+ ASSERT_TRUE(re.Match(buf.ToString(), &matches));
+ ASSERT_FALSE(matches.empty()) << "No leader match in: " << buf.ToString();
+
+ leader_addresses.insert(matches[0]);
+ }
+
+ // All masters should report the same leader
+ ASSERT_EQ(1, leader_addresses.size())
+ << JoinStrings(leader_addresses, ", ");
+
+ string leader_addr = *leader_addresses.begin();
+ ASSERT_FALSE(leader_addr.empty());
+ EasyCurl leader_curl;
+ faststring leader_buf;
+ leader_curl.set_verbose(true);
+ ASSERT_OK(leader_curl.FetchURL(Substitute("$0/api/v1/tables", leader_addr),
+ &leader_buf));
+ ASSERT_STR_CONTAINS(leader_buf.ToString(), "{\"tables\":[]}");
+}
+
} // namespace master
} // namespace kudu
diff --git a/src/kudu/master/rest_catalog_path_handlers.cc
b/src/kudu/master/rest_catalog_path_handlers.cc
index ee5ecd626..8ae1f3e25 100644
--- a/src/kudu/master/rest_catalog_path_handlers.cc
+++ b/src/kudu/master/rest_catalog_path_handlers.cc
@@ -22,12 +22,15 @@
#include <string>
#include <unordered_map>
#include <utility>
+#include <vector>
#include <gflags/gflags.h>
#include <google/protobuf/stubs/status.h>
#include <google/protobuf/util/json_util.h>
#include "kudu/common/common.pb.h"
+#include "kudu/common/wire_protocol.pb.h"
+#include "kudu/consensus/metadata.pb.h"
#include "kudu/gutil/ref_counted.h"
#include "kudu/gutil/strings/substitute.h"
#include "kudu/master/catalog_manager.h"
@@ -64,9 +67,11 @@ TAG_FLAG(rest_catalog_default_request_timeout_ms, runtime);
using google::protobuf::util::JsonParseOptions;
using google::protobuf::util::JsonStringToMessage;
+using kudu::consensus::RaftPeerPB;
using std::optional;
using std::ostringstream;
using std::string;
+using std::vector;
using strings::Substitute;
namespace kudu {
@@ -164,7 +169,50 @@ void
RestCatalogPathHandlers::HandleApiTablesEndpoint(const Webserver::WebReques
}
}
-void RestCatalogPathHandlers::HandleGetTables(ostringstream* output,
+void RestCatalogPathHandlers::HandleLeaderEndpoint(const
Webserver::WebRequest& req,
+
Webserver::PrerenderedWebResponse* resp) {
+ ostringstream* output = &resp->output;
+ JsonWriter jw(output, JsonWriter::COMPACT);
+
+ if (req.request_method != "GET") {
+ RETURN_JSON_ERROR(
+ jw, "Method not allowed", resp->status_code,
HttpStatusCode::MethodNotAllowed);
+ }
+ CatalogManager::ScopedLeaderSharedLock l(master_->catalog_manager());
+ vector<ServerEntryPB> masters;
+ Status s = master_->ListMasters(&masters,
+ /*use_external_addr=*/false);
+
+ if (!s.ok()) {
+ RETURN_JSON_ERROR(
+ jw, "unable to list masters", resp->status_code,
HttpStatusCode::InternalServerError);
+ }
+
+ for (const auto& master : masters) {
+ if (master.has_error() || master.role() != RaftPeerPB::LEADER) {
+ continue;
+ }
+
+ const ServerRegistrationPB& reg = master.registration();
+
+ if (reg.http_addresses().empty()) {
+ RETURN_JSON_ERROR(
+ jw, "leader master has no http address", resp->status_code,
HttpStatusCode::NotFound);
+ }
+ jw.StartObject();
+ jw.String("leader");
+ jw.String(Substitute("$0://$1:$2",
+ reg.https_enabled() ? "https" : "http",
+ reg.http_addresses(0).host(),
+ reg.http_addresses(0).port()));
+ jw.EndObject();
+ resp->status_code = HttpStatusCode::Ok;
+ return;
+ }
+ RETURN_JSON_ERROR(jw, "No leader master found", resp->status_code,
HttpStatusCode::NotFound);
+}
+
+void RestCatalogPathHandlers::HandleGetTables(std::ostringstream* output,
const Webserver::WebRequest& req,
HttpStatusCode* status_code) {
ListTablesRequestPB request;
@@ -386,6 +434,14 @@ void RestCatalogPathHandlers::Register(Webserver* server) {
},
StyleMode::JSON,
false);
+ server->RegisterPrerenderedPathHandler(
+ "/api/v1/leader",
+ "",
+ [this](const Webserver::WebRequest& req,
Webserver::PrerenderedWebResponse* resp) {
+ this->HandleLeaderEndpoint(req, resp);
+ },
+ StyleMode::JSON,
+ false);
}
} // namespace master
diff --git a/src/kudu/master/rest_catalog_path_handlers.h
b/src/kudu/master/rest_catalog_path_handlers.h
index a4f0d97ce..89c51065a 100644
--- a/src/kudu/master/rest_catalog_path_handlers.h
+++ b/src/kudu/master/rest_catalog_path_handlers.h
@@ -45,6 +45,8 @@ class RestCatalogPathHandlers final {
Webserver::PrerenderedWebResponse* resp);
void HandleApiTablesEndpoint(const Webserver::WebRequest& req,
Webserver::PrerenderedWebResponse* resp);
+ void HandleLeaderEndpoint(const Webserver::WebRequest& req,
+ Webserver::PrerenderedWebResponse* resp);
// Handles REST API endpoints based on the request method and path.
void HandleGetTables(std::ostringstream* output,
