feat: prom support drop metrics and external_labels

core/plugin/processor/inner/ProcessorPromRelabelMetricNative.cpp

@@ -126,6 +126,21 @@ bool ProcessorPromRelabelMetricNative::ProcessEvent(PipelineEventPtr& e,
         sourceEvent.DelTag(k);
     }
 
+    for (const auto& [k, v] : mScrapeConfigPtr->mExternalLabels) {
+        if (sourceEvent.HasTag(k)) {
+            if (!mScrapeConfigPtr->mHonorLabels) {
+                // metric event labels is secondary
+                // if confiliction, then rename it exported_<label_name>
+                auto key = prometheus::EXPORTED_PREFIX + k;
+                auto b = sourceEvent.GetSourceBuffer()->CopyString(key);
+                sourceEvent.SetTagNoCopy(StringView(b.data, b.size), sourceEvent.GetTag(k));
+                sourceEvent.SetTagNoCopy(k, v);
+            }
+        } else {
+            sourceEvent.SetTagNoCopy(k, v);
+        }
+    }
+
     // set metricEvent name
     sourceEvent.SetTagNoCopy(prometheus::NAME, sourceEvent.GetName());
 

core/prometheus/Constants.h

@@ -19,6 +19,7 @@ const char* const SOURCE_LABELS = "source_labels";
 const char* const SEPARATOR = "separator";
 const char* const TARGET_LABEL = "target_label";
 const char* const REGEX = "regex";
+const char* const MATCH_LIST = "match_list";
 const char* const REPLACEMENT = "replacement";
 const char* const ACTION = "action";
 const char* const MODULUS = "modulus";
@@ -78,6 +79,7 @@ const char* const KEY_FILE = "key_file";
 const char* const SERVER_NAME = "server_name";
 const char* const HOST = "Host";
 const char* const INSECURE_SKIP_VERIFY = "insecure_skip_verify";
+const char* const EXTERNAL_LABELS = "external_labels";
 
 // scrape protocols, from https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config
 // text/plain, application/openmetrics-text will be used

core/prometheus/labels/Relabel.cpp

@@ -18,13 +18,12 @@
 
 #include <openssl/md5.h>
 
+#include <boost/algorithm/string.hpp>
+#include <boost/algorithm/string/join.hpp>
+#include <boost/regex.hpp>
 #include <string>
 #include <vector>
 
-#include "boost/algorithm/string.hpp"
-#include "boost/algorithm/string/join.hpp"
-#include "boost/regex.hpp"
-
 #include "common/ParamExtractor.h"
 #include "common/StringTools.h"
 #include "logger/Logger.h"
@@ -49,7 +48,8 @@ Action StringToAction(const string& action) {
                                                    STRING_TO_ENUM_CASE(LABELDROP),
                                                    STRING_TO_ENUM_CASE(LABELKEEP),
                                                    STRING_TO_ENUM_CASE(LOWERCASE),
-                                                   STRING_TO_ENUM_CASE(UPPERCASE)};
+                                                   STRING_TO_ENUM_CASE(UPPERCASE),
+                                                   STRING_TO_ENUM_CASE(DROPMETRIC)};
 
     auto it = sActionStrings.find(action);
     if (it != sActionStrings.end()) {
@@ -69,7 +69,9 @@ const std::string& ActionToString(Action action) {
                                                         ENUM_TO_STRING_CASE(LABELDROP),
                                                         ENUM_TO_STRING_CASE(LABELKEEP),
                                                         ENUM_TO_STRING_CASE(LOWERCASE),
-                                                        ENUM_TO_STRING_CASE(UPPERCASE)};
+                                                        ENUM_TO_STRING_CASE(UPPERCASE),
+                                                        ENUM_TO_STRING_CASE(DROPMETRIC)};
+
     static string sUndefined = prometheus::UNDEFINED;
     auto it = sActionStrings.find(action);
     if (it != sActionStrings.end()) {
@@ -107,6 +109,26 @@ bool RelabelConfig::Init(const Json::Value& config) {
     if (config.isMember(prometheus::ACTION) && config[prometheus::ACTION].isString()) {
         string actionString = config[prometheus::ACTION].asString();
         mAction = StringToAction(actionString);
+    } else {
+        LOG_ERROR(sLogger, ("no action specified", ""));
+        return false;
+    }
+
+    if (mAction == Action::DROPMETRIC) {
+        mSourceLabels.emplace_back(prometheus::NAME);
+        if (config.isMember(prometheus::MATCH_LIST) && config[prometheus::MATCH_LIST].isArray()) {
+            for (const auto& item : config[prometheus::MATCH_LIST]) {
+                if (item.isString()) {
+                    mMatchList.insert(item.asString());
+                } else {
+                    LOG_ERROR(sLogger, ("invalid match_list item", ""));
+                    return false;
+                }
+            }
+        } else {
+            LOG_ERROR(sLogger, ("no match_list specified", ""));
+            return false;
+        }
     }
 
     if (config.isMember(prometheus::MODULUS) && config[prometheus::MODULUS].isUInt64()) {
@@ -219,6 +241,12 @@ bool RelabelConfig::Process(Labels& l, vector<string>& toDelete) const {
             }
             break;
         }
+        case Action::DROPMETRIC: {
+            if (mMatchList.find(val) != mMatchList.end()) {
+                return false;
+            }
+            break;
+        }
         default:
             // error
             LOG_ERROR(sLogger, ("relabel: unknown relabel action type", ActionToString(mAction)));

core/prometheus/labels/Relabel.h

@@ -15,10 +15,10 @@
  */
 
 #pragma once
-#include <string>
+#include <json/json.h>
 
-#include "boost/regex.hpp"
-#include "json/json.h"
+#include <boost/regex.hpp>
+#include <string>
 
 #include "prometheus/labels/Labels.h"
 
@@ -36,6 +36,7 @@ enum class Action {
     LABELKEEP,
     LOWERCASE,
     UPPERCASE,
+    DROPMETRIC,
     UNDEFINED
 };
 
@@ -65,6 +66,8 @@ class RelabelConfig {
     // Action is the action to be performed for the relabeling.
     Action mAction;
 
+    std::set<std::string> mMatchList;
+
 private:
     void CollectLabelsToDelete(const std::string& labelName, std::vector<std::string>& toDelete) const;
 };

core/prometheus/schedulers/ScrapeConfig.cpp

@@ -183,6 +183,13 @@ bool ScrapeConfig::InitStaticConfig(const Json::Value& scrapeConfig) {
             return false;
         }
     }
+
+    if (scrapeConfig.isMember(prometheus::EXTERNAL_LABELS)) {
+        if (!InitExternalLabels(scrapeConfig[prometheus::EXTERNAL_LABELS])) {
+            LOG_ERROR(sLogger, ("external labels config error", ""));
+            return false;
+        }
+    }
     return true;
 }
 
@@ -397,4 +404,20 @@ bool ScrapeConfig::InitTLSConfig(const Json::Value& tlsConfig) {
     return true;
 }
 
+bool ScrapeConfig::InitExternalLabels(const Json::Value& externalLabels) {
+    if (!externalLabels.isObject()) {
+        LOG_ERROR(sLogger, ("external_labels config error", ""));
+        return false;
+    }
+    for (auto& key : externalLabels.getMemberNames()) {
+        if (externalLabels[key].isString()) {
+            mExternalLabels.emplace_back(key, externalLabels[key].asString());
+        } else {
+            LOG_ERROR(sLogger, ("external_labels config error", ""));
+            return false;
+        }
+    }
+    return true;
+}
+
 } // namespace logtail

core/prometheus/schedulers/ScrapeConfig.h

@@ -44,6 +44,8 @@ class ScrapeConfig {
 
     std::string mQueryString;
 
+    std::vector<std::pair<std::string, std::string>> mExternalLabels;
+
     ScrapeConfig();
     bool Init(const Json::Value& config);
     bool InitStaticConfig(const Json::Value& config);
@@ -54,6 +56,7 @@ class ScrapeConfig {
     bool InitScrapeProtocols(const Json::Value& scrapeProtocols);
     void InitEnableCompression(bool enableCompression);
     bool InitTLSConfig(const Json::Value& tlsConfig);
+    bool InitExternalLabels(const Json::Value& externalLabels);
 
 #ifdef APSARA_UNIT_TEST_MAIN
     friend class ScrapeConfigUnittest;

core/unittest/processor/ProcessorPromRelabelMetricNativeUnittest.cpp

@@ -110,7 +110,11 @@ void ProcessorPromRelabelMetricNativeUnittest::TestProcess() {
                     ],
                     "target_label": "__address__"
                 }
-            ]
+            ],
+            "external_labels": {
+                "test_key1": "test_value1",
+                "test_key2": "test_value2"
+            }
         }
     )";
 
@@ -151,6 +155,10 @@ test_metric8{k1="v1", k3="v2", } 9.9410452992e+10 1715829785083
     APSARA_TEST_EQUAL("test_metric6", eventGroup.GetEvents().at(5).Cast<MetricEvent>().GetName());
     APSARA_TEST_EQUAL("test_metric7", eventGroup.GetEvents().at(6).Cast<MetricEvent>().GetName());
     // test_metric8 is dropped by relabel config
+
+    // check external labels
+    APSARA_TEST_EQUAL("test_value1", eventGroup.GetEvents().at(0).Cast<MetricEvent>().GetTag("test_key1"));
+    APSARA_TEST_EQUAL("test_value2", eventGroup.GetEvents().at(0).Cast<MetricEvent>().GetTag("test_key2"));
 }
 
 void ProcessorPromRelabelMetricNativeUnittest::TestAddAutoMetrics() {

core/unittest/prometheus/RelabelUnittest.cpp

@@ -39,6 +39,7 @@ class RelabelConfigUnittest : public testing::Test {
     void TestReplace();
     void TestKeep();
     void TestDrop();
+    void TestDropMetric();
     void TestDropEqual();
     void TestHashMod();
     void TestLabelDrop();
@@ -200,6 +201,31 @@ void RelabelConfigUnittest::TestDrop() {
     APSARA_TEST_FALSE(configList.Process(result, toDelete));
 }
 
+void RelabelConfigUnittest::TestDropMetric() {
+    Json::Value configJson;
+    string configStr;
+    string errorMsg;
+    RelabelConfigList configList;
+    Labels labels;
+    labels.Set("__meta_kubernetes_pod_ip", "172.17.0.3");
+    labels.Set("__meta_kubernetes_pod_label_app", "node-exporter");
+    labels.Set("__name__", "node_cpu_seconds_total");
+    // single relabel drop
+    configStr = R"(
+        [{
+                "action": "dropmetric",
+                "match_list": ["test_1","node_cpu_seconds_total"]
+        }]
+    )";
+
+    APSARA_TEST_TRUE(ParseJsonTable(configStr, configJson, errorMsg));
+    configList = RelabelConfigList();
+    APSARA_TEST_TRUE(configList.Init(configJson));
+    auto result = labels;
+    vector<string> toDelete;
+    APSARA_TEST_FALSE(configList.Process(result, toDelete));
+}
+
 void RelabelConfigUnittest::TestDropEqual() {
     Json::Value configJson;
     string configStr;
@@ -495,6 +521,7 @@ UNIT_TEST_CASE(ActionConverterUnittest, TestActionToString)
 UNIT_TEST_CASE(RelabelConfigUnittest, TestRelabelConfig)
 UNIT_TEST_CASE(RelabelConfigUnittest, TestReplace)
 UNIT_TEST_CASE(RelabelConfigUnittest, TestDrop)
+UNIT_TEST_CASE(RelabelConfigUnittest, TestDropMetric)
 UNIT_TEST_CASE(RelabelConfigUnittest, TestKeep)
 UNIT_TEST_CASE(RelabelConfigUnittest, TestHashMod)
 UNIT_TEST_CASE(RelabelConfigUnittest, TestLabelMap)

core/unittest/prometheus/ScrapeConfigUnittest.cpp

@@ -94,6 +94,10 @@ void ScrapeConfigUnittest::TestInit() {
                     ]
                 }
             ],
+            "external_labels": {
+                "test_key1": "test_value1",
+                "test_key2": "test_value2"
+            },
             "params" : {
                 "__param_query": [
                     "test_query"
@@ -142,6 +146,13 @@ void ScrapeConfigUnittest::TestInit() {
     APSARA_TEST_EQUAL(scrapeConfig.mRelabelConfigs.mRelabelConfigs.size(), 1UL);
     APSARA_TEST_EQUAL(scrapeConfig.mParams["__param_query"][0], "test_query");
     APSARA_TEST_EQUAL(scrapeConfig.mParams["__param_query_1"][0], "test_query_1");
+
+    // external labels
+    APSARA_TEST_EQUAL(scrapeConfig.mExternalLabels.size(), 2UL);
+    APSARA_TEST_EQUAL(scrapeConfig.mExternalLabels[0].first, "test_key1");
+    APSARA_TEST_EQUAL(scrapeConfig.mExternalLabels[0].second, "test_value1");
+    APSARA_TEST_EQUAL(scrapeConfig.mExternalLabels[1].first, "test_key2");
+    APSARA_TEST_EQUAL(scrapeConfig.mExternalLabels[1].second, "test_value2");
 }
 
 void ScrapeConfigUnittest::TestAuth() {