add prometheus metrics ut

test/brpc_prometheus_metrics_unittest.cpp

+// brpc - A framework to host and access services throughout Baidu.
+// Copyright (c) 2018 BiliBili, Inc.
+// Author: Jiashun Zhu(zhujiashun@bilibili.com)
+// Date: Tue Dec 3 11:27:18 CST 2018
+
+#include <gtest/gtest.h>
+#include "brpc/server.h"
+#include "brpc/channel.h"
+#include "brpc/controller.h"
+#include "butil/strings/string_piece.h"
+#include "echo.pb.h"
+
+int main(int argc, char* argv[]) {
+    testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}
+
+class DummyEchoServiceImpl : public test::EchoService {
+public:
+    virtual ~DummyEchoServiceImpl() {}
+    virtual void Echo(google::protobuf::RpcController* cntl_base,
+                      const test::EchoRequest* request,
+                      test::EchoResponse* response,
+                      google::protobuf::Closure* done) {
+        brpc::ClosureGuard done_guard(done);
+        return;
+    }
+};
+
+enum STATE {
+    HELP = 0,
+    TYPE,
+    GAUGE,
+    SUMMARY
+};
+
+TEST(PROMETHEUS_METRICS, sanity) {
+    brpc::Server server;
+    DummyEchoServiceImpl echo_svc;
+    ASSERT_EQ(0, server.AddService(&echo_svc, brpc::SERVER_DOESNT_OWN_SERVICE));
+    ASSERT_EQ(0, server.Start("127.0.0.1:8614", NULL));
+
+    brpc::Channel channel;
+    brpc::ChannelOptions channel_opts;
+    channel_opts.protocol = "http";
+    ASSERT_EQ(0, channel.Init("127.0.0.1:8614", &channel_opts));
+    brpc::Controller cntl;
+    cntl.http_request().uri() = "/metrics";
+    channel.CallMethod(NULL, &cntl, NULL, NULL, NULL);
+    ASSERT_FALSE(cntl.Failed());
+    std::string res = cntl.response_attachment().to_string();
+
+    size_t start_pos = 0;
+    size_t end_pos = 0;
+    STATE state = HELP;
+    char name_help[128];
+    char name_type[128];
+    char type[16];
+    int matched = 0;
+    int gauge_num = 0;
+    bool summary_sum_gathered = false;
+    bool summary_count_gathered = false;
+
+    while ((end_pos = res.find('\n', start_pos)) != butil::StringPiece::npos) {
+        res[end_pos] = '\0';       // safe;
+        switch (state) {
+            case HELP:
+                matched = sscanf(res.data() + start_pos, "# HELP %s", name_help);
+                ASSERT_EQ(1, matched);
+                state = TYPE;
+                break;
+            case TYPE:
+                matched = sscanf(res.data() + start_pos, "# TYPE %s %s", name_type, type);
+                ASSERT_EQ(2, matched);
+                ASSERT_STREQ(name_type, name_help);
+                if (strcmp(type, "gauge") == 0) {
+                    state = GAUGE;
+                } else if (strcmp(type, "summary") == 0) {
+                    state = SUMMARY;
+                } else {
+                    ASSERT_TRUE(false);
+                }
+                break;
+            case GAUGE:
+                matched = sscanf(res.data() + start_pos, "%s %d", name_type, &gauge_num);
+                ASSERT_EQ(2, matched);
+                ASSERT_STREQ(name_type, name_help);
+                state = HELP;
+                break;
+            case SUMMARY:
+                if (butil::StringPiece(res.data() + start_pos, end_pos - start_pos).find("quantile=")
+                        == butil::StringPiece::npos) {
+                    matched = sscanf(res.data() + start_pos, "%s %d", name_type, &gauge_num);
+                    ASSERT_EQ(2, matched);
+                    ASSERT_TRUE(strncmp(name_type, name_help, strlen(name_help)) == 0);
+                    if (butil::StringPiece(name_type).ends_with("_sum")) {
+                        ASSERT_FALSE(summary_sum_gathered);
+                        summary_sum_gathered = true;
+                    } else if (butil::StringPiece(name_type).ends_with("_count")) {
+                        ASSERT_FALSE(summary_count_gathered);
+                        summary_count_gathered = true;
+                    } else {
+                        ASSERT_TRUE(false);
+                    }
+                    if (summary_sum_gathered && summary_count_gathered) {
+                        state = HELP;
+                        summary_sum_gathered = false;
+                        summary_count_gathered = false;
+                    }
+                } // else find "quantile=", just break to next line
+                break;
+            default:
+                ASSERT_TRUE(false);
+                break;
+        }
+        start_pos = end_pos + 1;
+    }
+    ASSERT_EQ(0, server.Stop(0));
+    ASSERT_EQ(0, server.Join());
+}