feat: better control over RCDB URL choice

src/iguana/algorithms/physics/InclusiveKinematics/Algorithm.cc

@@ -33,7 +33,7 @@ namespace iguana::physics {
     i_qE     = result_schema.getEntryOrder("qE");
 
     // instantiate RCDB reader
-    m_rcdb = std::make_unique<RCDBReader>("RCDB|" + GetName());
+    m_rcdb = std::make_unique<RCDBReader>("RCDB|" + GetName(), m_log->GetLevel());
 
     // parse config file
     ParseYAMLConfig();

src/iguana/services/GlobalParam.cc

@@ -4,6 +4,7 @@ namespace iguana {
 
   // default param values
   GlobalParam<std::string> GlobalConcurrencyModel{"none"};
+  GlobalParam<std::string> GlobalRcdbUrl{""};
 
   // template specializations
   template class GlobalParam<std::string>;

src/iguana/services/GlobalParam.h

@@ -64,4 +64,12 @@ namespace iguana {
   ///   option will be _chosen_ by `ConcurrentParamFactory::Create` instead
   extern GlobalParam<std::string> GlobalConcurrencyModel;
 
+  /// @brief RCDB URL
+  /// @par Notes
+  /// The RCDB will check for a URL in the following order:
+  /// - This parameter, `iguana::GlobalRcdbUrl`; by default it is not set to any value
+  /// - The environment variable `RCDB_CONNECTION` (which is likely set if you are on `ifarm`)
+  /// - A default URL, which will be printed in a warning; see `iguana::RCDBReader::m_default_url`
+  extern GlobalParam<std::string> GlobalRcdbUrl;
+
 }

src/iguana/services/Object.cc

@@ -2,9 +2,9 @@
 
 namespace iguana {
 
-  Object::Object(std::string_view name)
+  Object::Object(std::string_view name, Logger::Level lev)
       : m_name(name)
-      , m_log(std::make_unique<Logger>(m_name))
+      , m_log(std::make_unique<Logger>(m_name, lev))
   {}
 
   std::unique_ptr<Logger>& Object::Log()

src/iguana/services/Object.h

@@ -14,7 +14,8 @@ namespace iguana {
     public:
 
       /// @param name the name of this object
-      Object(std::string_view name = "");
+      /// @param lev the log level
+      Object(std::string_view name = "", Logger::Level lev = Logger::DEFAULT_LEVEL);
       ~Object() {}
 
       /// Get the logger

src/iguana/services/RCDBReader.cc

@@ -1,14 +1,34 @@
 #include "RCDBReader.h"
+#include "GlobalParam.h"
 
 namespace iguana {
 
-  RCDBReader::RCDBReader(std::string_view name) : Object(name)
+  RCDBReader::RCDBReader(std::string_view name, Logger::Level lev) : Object(name, lev)
   {
 #ifdef USE_RCDB
-    auto url_ptr = std::getenv("RCDB_CONNECTION");
-    m_url = url_ptr != nullptr ? std::string(url_ptr) : default_url;
-    m_log->Debug("RCDB URL: {}", m_url);
+
+    // choose the RCDB URL, from the following priority ordering
+    // 1. try `GlobalRcdbUrl`
+    m_url = GlobalRcdbUrl();
+    if(!m_url.empty())
+      m_log->Debug("RCDB URL set from 'iguana::GlobalRcdbUrl': {:?}", m_url);
+    else {
+      // 2. try env var `RCDB_CONNECTION`
+      if(auto url_ptr{std::getenv("RCDB_CONNECTION")}; url_ptr != nullptr)
+        m_url = std::string(url_ptr);
+      if(!m_url.empty())
+        m_log->Debug("RCDB URL set from env var 'RCDB_CONNECTION': {:?}", m_url);
+      else {
+        // 3. fallback to default value
+        m_log->Warn("RCDB URL not set; you may choose a URL with the environment variable 'RCDB_CONNECTION' or with the global parameter 'iguana::GlobalRcdbUrl'; for now, let's proceed with the URL set to {:?}", m_default_url);
+        m_url = m_default_url;
+        m_log->Debug("RCDB URL set from default fallback: {:?}", m_url);
+      }
+    }
+
+    // then start the connection
     m_rcdb_connection = std::make_unique<rcdb::Connection>(m_url, true);
+
 #endif
   }
 

src/iguana/services/RCDBReader.h

@@ -16,16 +16,19 @@ namespace iguana {
     public:
 
       /// @param name the name of this reader
-      RCDBReader(std::string_view name = "rcdb");
+      /// @param lev the log level
+      RCDBReader(std::string_view name = "rcdb", Logger::Level lev = Logger::DEFAULT_LEVEL);
 
       /// @param runnum run number
       /// @returns the beam energy in GeV
       double GetBeamEnergy(int const runnum);
 
     private:
 
+      /// @brief default RCDB URL, used as a last resort
+      std::string const m_default_url = "mysql://[email protected]/rcdb";
+
       std::string m_url;
-      std::string const default_url = "mysql://[email protected]/rcdb";
       std::once_flag m_error_once;
 
 #ifdef USE_RCDB