Fixup mbvar convert prometheus metrics format issue (#2082)

src/brpc/builtin/prometheus_metrics_service.cpp

@@ -82,6 +82,12 @@ class PrometheusMetricsDumper : public bvar::Dumper {
     std::map<std::string, SummaryItems> _m;
 };
 
+butil::StringPiece GetMetricsName(const std::string& name) {
+    auto pos = name.find_first_of('{');
+    int size = (pos == std::string::npos) ? name.size() : pos;
+    return butil::StringPiece(name.data(), size);
+}
+
 bool PrometheusMetricsDumper::dump(const std::string& name,
                                    const butil::StringPiece& desc) {
     if (!desc.empty() && desc[0] == '"') {
@@ -93,8 +99,11 @@ bool PrometheusMetricsDumper::dump(const std::string& name,
         // Leave it to DumpLatencyRecorderSuffix to output Summary.
         return true;
     }
-    *_os << "# HELP " << name << '\n'
-         << "# TYPE " << name << " gauge" << '\n'
+
+    auto metrics_name = GetMetricsName(name);
+
+    *_os << "# HELP " << metrics_name << '\n'
+         << "# TYPE " << metrics_name << " gauge" << '\n'
          << name << " " << desc << '\n';
     return true;
 }

src/brpc/builtin/prometheus_metrics_service.h

@@ -31,6 +31,7 @@ class PrometheusMetricsService : public brpc_metrics {
                         ::google::protobuf::Closure* done) override;
 };
 
+butil::StringPiece GetMetricsName(const std::string& name);
 int DumpPrometheusMetricsToIOBuf(butil::IOBuf* output);
 
 } // namepace brpc

test/brpc_prometheus_metrics_service_unittest.cpp

@@ -0,0 +1,42 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+// Date: 2023/05/06 15:10:00
+
+#include <gtest/gtest.h>
+
+#include "butil/strings/string_piece.h"
+#include "butil/iobuf.h"
+#include "brpc/builtin/prometheus_metrics_service.h"
+
+namespace {
+
+class PrometheusMetricsDumperTest : public testing::Test {
+protected:
+    void SetUp() {}
+    void TearDown() {}
+};
+
+TEST_F(PrometheusMetricsDumperTest, GetMetricsName) {
+  EXPECT_EQ("", brpc::GetMetricsName(""));
+
+  EXPECT_EQ("commit_count", brpc::GetMetricsName("commit_count"));
+
+  EXPECT_EQ("commit_count", brpc::GetMetricsName("commit_count{region=\"1000\"}"));
+}
+
+}