Add dotenv config support

CMakeLists.txt

@@ -242,6 +242,7 @@ set(DROGON_SOURCES
     lib/src/CacheFile.cc
     lib/src/ConfigLoader.cc
     lib/src/Cookie.cc
+    lib/src/DotenvParser.cc
     lib/src/DrClassMap.cc
     lib/src/DrTemplateBase.cc
     lib/src/FiltersFunction.cc

lib/inc/drogon/HttpAppFramework.h

@@ -386,6 +386,16 @@ class DROGON_EXPORT HttpAppFramework : public trantor::NonCopyable
      */
     virtual HttpAppFramework &loadConfigJson(Json::Value &&data) = 0;
 
+    /// Load the configuration file with dotenv format
+    /// defaults to filename ".env" in the current working directory.
+    virtual HttpAppFramework &loadConfigDotenv() = 0;
+
+    /// Load the configuration file with dotenv format.
+    /**
+     * @param filename the configuration file
+     */
+    virtual HttpAppFramework &loadConfigDotenv(const std::string &fileName) = 0;
+
     /// Register a HttpSimpleController object into the framework.
     /**
      * @param pathName When the path of a http request is equal to the

lib/src/ConfigLoader.cc

@@ -13,6 +13,7 @@
  */
 
 #include "ConfigLoader.h"
+#include "DotenvParser.h"
 #include "HttpAppFrameworkImpl.h"
 #include <drogon/config.h>
 #include <fstream>
@@ -101,14 +102,11 @@ ConfigLoader::ConfigLoader(const std::string &configFile)
 {
     if (os_access(drogon::utils::toNativePath(configFile).c_str(), 0) != 0)
     {
-        std::cerr << "Config file " << configFile << " not found!" << std::endl;
-        exit(1);
+        LOG_FATAL << "Config file " << configFile << " not found!";
     }
     if (os_access(drogon::utils::toNativePath(configFile).c_str(), R_OK) != 0)
     {
-        std::cerr << "No permission to read config file " << configFile
-                  << std::endl;
-        exit(1);
+        LOG_FATAL << "No permission to read config file " << configFile;
     }
     configFile_ = configFile;
     std::ifstream infile(drogon::utils::toNativePath(configFile).c_str(),
@@ -121,10 +119,43 @@ ConfigLoader::ConfigLoader(const std::string &configFile)
         }
         catch (const std::exception &exception)
         {
-            std::cerr << "Configuration file format error! in " << configFile
-                      << ":" << std::endl;
-            std::cerr << exception.what() << std::endl;
-            exit(1);
+            LOG_FATAL << "Configuration file format error! in " << configFile
+                      << ":" << exception.what();
+        }
+    }
+}
+ConfigLoader::ConfigLoader(const std::string &configFile, ConfigSyntax syntax)
+{
+    if (os_access(drogon::utils::toNativePath(configFile).c_str(), 0) != 0)
+    {
+        LOG_FATAL << "Config file " << configFile << " not found!";
+    }
+    if (os_access(drogon::utils::toNativePath(configFile).c_str(), R_OK) != 0)
+    {
+        LOG_FATAL << "No permission to read config file " << configFile;
+    }
+    configFile_ = configFile;
+    std::ifstream infile(drogon::utils::toNativePath(configFile).c_str(),
+                         std::ifstream::in);
+    if (infile)
+    {
+        try
+        {
+            if (syntax == kDotENV)
+            {
+                DotenvParser parser;
+                parser.parse(infile);
+                configJsonRoot_ = parser.jsonValue();
+            }
+            else
+            {
+                infile >> configJsonRoot_;
+            }
+        }
+        catch (const std::exception &exception)
+        {
+            LOG_FATAL << "Configuration file format error! in " << configFile
+                      << ":" << exception.what();
         }
     }
 }
@@ -269,8 +300,7 @@ static void loadApp(const Json::Value &app)
         }
         else
         {
-            std::cerr << "The static_file_headers option must be an array\n";
-            exit(1);
+            LOG_FATAL << "The static_file_headers option must be an array";
         }
     }
     // upload path
@@ -294,8 +324,7 @@ static void loadApp(const Json::Value &app)
         auto &locations = app["locations"];
         if (!locations.isArray())
         {
-            std::cerr << "The locations option must be an array\n";
-            exit(1);
+            LOG_FATAL << "The locations option must be an array";
         }
         for (auto &location : locations)
         {
@@ -328,9 +357,8 @@ static void loadApp(const Json::Value &app)
                 }
                 else
                 {
-                    std::cerr << "the filters of location '" << uri
-                              << "' should be an array" << std::endl;
-                    exit(1);
+                    LOG_FATAL << "the filters of location '" << uri
+                              << "' should be an array";
                 }
             }
             else
@@ -442,8 +470,7 @@ static void loadApp(const Json::Value &app)
     }
     else
     {
-        std::cerr << "Error format of client_max_body_size" << std::endl;
-        exit(1);
+        LOG_FATAL << "Error format of client_max_body_size";
     }
     auto maxMemoryBodySize =
         app.get("client_max_memory_body_size", "64K").asString();
@@ -453,8 +480,7 @@ static void loadApp(const Json::Value &app)
     }
     else
     {
-        std::cerr << "Error format of client_max_memory_body_size" << std::endl;
-        exit(1);
+        LOG_FATAL << "Error format of client_max_memory_body_size";
     }
     auto maxWsMsgSize =
         app.get("client_max_websocket_message_size", "128K").asString();
@@ -464,9 +490,7 @@ static void loadApp(const Json::Value &app)
     }
     else
     {
-        std::cerr << "Error format of client_max_websocket_message_size"
-                  << std::endl;
-        exit(1);
+        LOG_FATAL << "Error format of client_max_websocket_message_size";
     }
     drogon::app().enableReusePort(app.get("reuse_port", false).asBool());
     drogon::app().setHomePage(app.get("home_page", "index.html").asString());
@@ -508,9 +532,7 @@ static void loadDbClients(const Json::Value &dbClients)
         auto dbname = client.get("dbname", "").asString();
         if (dbname == "" && type != "sqlite3")
         {
-            std::cerr << "Please configure dbname in the configuration file"
-                      << std::endl;
-            exit(1);
+            LOG_FATAL << "Please configure dbname in the configuration file";
         }
         auto user = client.get("user", "postgres").asString();
         auto password = client.get("passwd", "").asString();

lib/src/ConfigLoader.h

@@ -20,10 +20,17 @@
 
 namespace drogon
 {
+enum ConfigSyntax
+{
+    kJSON,
+    kDotENV
+};
+
 class ConfigLoader : public trantor::NonCopyable
 {
   public:
     explicit ConfigLoader(const std::string &configFile);
+    explicit ConfigLoader(const std::string &configFile, ConfigSyntax syntax);
     explicit ConfigLoader(const Json::Value &data);
     explicit ConfigLoader(Json::Value &&data);
     ~ConfigLoader();