admin: added json output support for stats handler (envoyproxy#1865)

Signed-off-by: Rama <[email protected]>
hecsalazar · Oct 19, 2017 · d5695aa · d5695aa
1 parent e366bcf
commit d5695aa
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Showing 5 changed files with 69 additions and 4 deletions.
diff --git a/.clang-format b/.clang-format
diff --git a/docs/operations/admin.rst b/docs/operations/admin.rst
@@ -137,3 +137,7 @@ The fields are:
   output as Envoy currently has no built in histogram support and relies on statsd for
   aggregation. This command is very useful for local debugging. See :ref:`here <operations_stats>`
   for more information.
+
+  .. http:get:: /stats?format=json
+
+  Outputs /stats in JSON format. This can be used for programmatic access of stats.
diff --git a/source/server/http/admin.cc b/source/server/http/admin.cc
@@ -31,8 +31,19 @@
 #include "common/upstream/host_utility.h"
 
 #include "fmt/format.h"
+
+// TODO(mattklein123): Switch to JSON interface methods and remove rapidjson dependency.
+#include "rapidjson/document.h"
+#include "rapidjson/error/en.h"
+#include "rapidjson/prettywriter.h"
+#include "rapidjson/reader.h"
+#include "rapidjson/schema.h"
+#include "rapidjson/stream.h"
+#include "rapidjson/stringbuffer.h"
 #include "spdlog/spdlog.h"
 
+using namespace rapidjson;
+
 namespace Envoy {
 namespace Server {
 
@@ -267,9 +278,11 @@ Http::Code AdminImpl::handlerServerInfo(const std::string&, Buffer::Instance& re
   return Http::Code::OK;
 }
 
-Http::Code AdminImpl::handlerStats(const std::string&, Buffer::Instance& response) {
+Http::Code AdminImpl::handlerStats(const std::string& url, Buffer::Instance& response) {
   // We currently don't support timers locally (only via statsd) so just group all the counters
   // and gauges together, alpha sort them, and spit them out.
+  Http::Code rc = Http::Code::OK;
+  const Http::Utility::QueryParams params = Http::Utility::parseQueryString(url);
   std::map<std::string, uint64_t> all_stats;
   for (const Stats::CounterSharedPtr& counter : server_.stats().counters()) {
     all_stats.emplace(counter->name(), counter->value());
@@ -279,11 +292,46 @@ Http::Code AdminImpl::handlerStats(const std::string&, Buffer::Instance& respons
     all_stats.emplace(gauge->name(), gauge->value());
   }
 
-  for (auto stat : all_stats) {
-    response.add(fmt::format("{}: {}\n", stat.first, stat.second));
+  if (params.size() == 0) {
+    // No Arguments so use the standard.
+    for (auto stat : all_stats) {
+      response.add(fmt::format("{}: {}\n", stat.first, stat.second));
+    }
+  } else {
+    const std::string format_key = params.begin()->first;
+    const std::string format_value = params.begin()->second;
+    if (format_key == "format" && format_value == "json") {
+      response.add(statsAsJson(all_stats));
+    } else {
+      response.add("usage: /stats?format=json \n");
+      response.add("\n");
+      rc = Http::Code::NotFound;
+    }
   }
+  return rc;
+}
 
-  return Http::Code::OK;
+std::string AdminImpl::statsAsJson(const std::map<std::string, uint64_t>& all_stats) {
+  rapidjson::Document document;
+  document.SetObject();
+  rapidjson::Value stats_array(rapidjson::kArrayType);
+  rapidjson::Document::AllocatorType& allocator = document.GetAllocator();
+  for (auto stat : all_stats) {
+    Value stat_obj;
+    stat_obj.SetObject();
+    Value stat_name;
+    stat_name.SetString(stat.first.c_str(), allocator);
+    stat_obj.AddMember("name", stat_name, allocator);
+    Value stat_value;
+    stat_value.SetInt(stat.second);
+    stat_obj.AddMember("value", stat_value, allocator);
+    stats_array.PushBack(stat_obj, allocator);
+  }
+  document.AddMember("stats", stats_array, allocator);
+  rapidjson::StringBuffer strbuf;
+  rapidjson::PrettyWriter<StringBuffer> writer(strbuf);
+  document.Accept(writer);
+  return strbuf.GetString();
 }
 
 Http::Code AdminImpl::handlerQuitQuitQuit(const std::string&, Buffer::Instance& response) {

diff --git a/source/server/http/admin.h b/source/server/http/admin.h
@@ -115,6 +115,7 @@ class AdminImpl : public Admin,
   void addOutlierInfo(const std::string& cluster_name,
                       const Upstream::Outlier::Detector* outlier_detector,
                       Buffer::Instance& response);
+  std::string statsAsJson(const std::map<std::string, uint64_t>& all_stats);
 
   /**
    * URL handlers.

diff --git a/test/integration/integration_admin_test.cc b/test/integration/integration_admin_test.cc
@@ -107,6 +107,18 @@ TEST_P(IntegrationAdminTest, Admin) {
   EXPECT_TRUE(response->complete());
   EXPECT_STREQ("200", response->headers().Status()->value().c_str());
 
+  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats?format=blah",
+                                                "", downstreamProtocol(), version_);
+  EXPECT_TRUE(response->complete());
+  EXPECT_STREQ("404", response->headers().Status()->value().c_str());
+
+  response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/stats?format=json",
+                                                "", downstreamProtocol(), version_);
+  EXPECT_TRUE(response->complete());
+  EXPECT_STREQ("200", response->headers().Status()->value().c_str());
+  Json::ObjectSharedPtr statsjson = Json::Factory::loadFromString(response->body());
+  EXPECT_TRUE(statsjson->hasObject("stats"));
+
   response = IntegrationUtil::makeSingleRequest(lookupPort("admin"), "GET", "/clusters", "",
                                                 downstreamProtocol(), version_);
   EXPECT_TRUE(response->complete());