From 7ae6a1dc2bdd6948d2cb3c48562a1d630931a178 Mon Sep 17 00:00:00 2001
From: quzard <1191890118@qq.com>
Date: Thu, 16 Jan 2025 20:21:36 +0800
Subject: [PATCH] Read new environment variables when calling LOAD_PARAMETER
 and LoadSingleValueEnvConfig (#2042)

---
 core/app_config/AppConfig.cpp                 | 16 ++++++++++
 core/app_config/AppConfig.h                   |  1 +
 core/common/JsonUtil.cpp                      | 10 +++++-
 .../unittest/app_config/AppConfigUnittest.cpp | 31 +++++++++++++++++++
 4 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/core/app_config/AppConfig.cpp b/core/app_config/AppConfig.cpp
index 2e939bcfab..af966d907f 100644
--- a/core/app_config/AppConfig.cpp
+++ b/core/app_config/AppConfig.cpp
@@ -24,6 +24,7 @@
 #include "json/value.h"
 
 #include "RuntimeUtil.h"
+#include "StringTools.h"
 #include "common/EnvUtil.h"
 #include "common/FileSystemUtil.h"
 #include "common/JsonUtil.h"
@@ -847,6 +848,21 @@ bool LoadSingleValueEnvConfig(const char* envKey, T& configValue, const T minVal
     } catch (const exception& e) {
         LOG_WARNING(sLogger, (string("set ") + envKey + " from env failed, exception", e.what()));
     }
+    try {
+        char* value = NULL;
+        const auto newEnvKey = LOONGCOLLECTOR_ENV_PREFIX + ToUpperCaseString(envKey);
+        value = getenv(newEnvKey.c_str());
+        if (value != NULL) {
+            T val = StringTo<T>(value);
+            if (val >= minValue) {
+                configValue = val;
+                LOG_INFO(sLogger, (string("set ") + envKey + " from env, value", value));
+                return true;
+            }
+        }
+    } catch (const exception& e) {
+        LOG_WARNING(sLogger, (string("set ") + envKey + " from env failed, exception", e.what()));
+    }
     return false;
 }
 
diff --git a/core/app_config/AppConfig.h b/core/app_config/AppConfig.h
index 35e9b991e1..c6458f644d 100644
--- a/core/app_config/AppConfig.h
+++ b/core/app_config/AppConfig.h
@@ -38,6 +38,7 @@ extern const uint32_t CONCURRENCY_STATISTIC_THRESHOLD;
 extern const uint32_t CONCURRENCY_STATISTIC_INTERVAL_THRESHOLD_SECONDS;
 extern const uint32_t NO_FALL_BACK_FAIL_PERCENTAGE;
 extern const uint32_t SLOW_FALL_BACK_FAIL_PERCENTAGE;
+extern const std::string LOONGCOLLECTOR_ENV_PREFIX;
 
 void CreateAgentDir();
 
diff --git a/core/common/JsonUtil.cpp b/core/common/JsonUtil.cpp
index 288f67283f..b182fcd61f 100644
--- a/core/common/JsonUtil.cpp
+++ b/core/common/JsonUtil.cpp
@@ -17,6 +17,7 @@
 #include <memory>
 #include <sstream>
 
+#include "AppConfig.h"
 #include "common/ExceptionBase.h"
 #include "common/StringTools.h"
 #include "logger/Logger.h"
@@ -194,10 +195,17 @@ bool LoadEnvValueIfExisting(const char* envKey, T& cfgValue) {
         loaded = true; \
         APSARA_LOG_INFO(sLogger, ("load parameter from env", name)("value", outVal)); \
     } \
-    if (envName != NULL && LoadEnvValueIfExisting(envName, value)) { \
+    if (envName != NULL && LoadEnvValueIfExisting(envName, outVal)) { \
         loaded = true; \
         APSARA_LOG_INFO(sLogger, ("load parameter from env", envName)("value", outVal)); \
     } \
+    if (name != NULL) { \
+        const auto newEnvName = LOONGCOLLECTOR_ENV_PREFIX + ToUpperCaseString(name); \
+        if (LoadEnvValueIfExisting(newEnvName.c_str(), outVal)) { \
+            loaded = true; \
+            APSARA_LOG_INFO(sLogger, ("load parameter from env", newEnvName)("value", outVal)); \
+        } \
+    } \
     if (name != NULL && (confJSON.isMember(name) && confJSON[name].testJSONFunc())) { \
         outVal = confJSON[name].convertJSONFunc(); \
         loaded = true; \
diff --git a/core/unittest/app_config/AppConfigUnittest.cpp b/core/unittest/app_config/AppConfigUnittest.cpp
index bba92f4564..7552f65782 100644
--- a/core/unittest/app_config/AppConfigUnittest.cpp
+++ b/core/unittest/app_config/AppConfigUnittest.cpp
@@ -37,6 +37,8 @@ class AppConfigUnittest : public ::testing::Test {
 public:
     void TestRecurseParseJsonToFlags();
     void TestParseEnvToFlags();
+    void TestLoadSingleValueEnvConfig();
+    void TestLoadStringParameter();
 
 private:
     void writeLogtailConfigJSON(const Json::Value& v) {
@@ -197,8 +199,37 @@ void AppConfigUnittest::TestParseEnvToFlags() {
     }
 }
 
+void AppConfigUnittest::TestLoadSingleValueEnvConfig() {
+    SetEnv("cpu_usage_limit", "0.5");
+    AppConfig::GetInstance()->LoadEnvResourceLimit();
+    APSARA_TEST_EQUAL(AppConfig::GetInstance()->GetCpuUsageUpLimit(), 0.5);
+    UnsetEnv("cpu_usage_limit");
+    SetEnv("LOONG_CPU_USAGE_LIMIT", "0.6");
+    AppConfig::GetInstance()->LoadEnvResourceLimit();
+    APSARA_TEST_EQUAL(AppConfig::GetInstance()->GetCpuUsageUpLimit(), float(0.6));
+    UnsetEnv("LOONG_CPU_USAGE_LIMIT");
+}
+
+void AppConfigUnittest::TestLoadStringParameter() {
+    Json::Value value;
+    std::string res;
+    SetEnv("cpu_usage_limit_env", "0.5");
+    LoadStringParameter(res, value, "cpu_usage_limit", "cpu_usage_limit_env");
+    APSARA_TEST_EQUAL(res, "0.5");
+
+    SetEnv("LOONG_CPU_USAGE_LIMIT", "0.6");
+    LoadStringParameter(res, value, "cpu_usage_limit", "cpu_usage_limit_env");
+    APSARA_TEST_EQUAL(res, "0.6");
+
+    value["cpu_usage_limit"] = "0.7";
+    LoadStringParameter(res, value, "cpu_usage_limit", "cpu_usage_limit_env");
+    APSARA_TEST_EQUAL(res, "0.7");
+}
+
 UNIT_TEST_CASE(AppConfigUnittest, TestRecurseParseJsonToFlags);
 UNIT_TEST_CASE(AppConfigUnittest, TestParseEnvToFlags);
+UNIT_TEST_CASE(AppConfigUnittest, TestLoadSingleValueEnvConfig);
+UNIT_TEST_CASE(AppConfigUnittest, TestLoadStringParameter);
 
 } // namespace logtail