allow for relative file paths in config (#1432)

* llarp::Config constructor can take an empty fs::path now and it will default to fs::current_path
* llarp::ensureConfig now throws on fs error
* updates to daemon/main.cpp to reflect changes to llarp::ensureConfig's new throwability
* dowse parts of the code with holy water for the 0.8.1 tag

daemon/main.cpp

@@ -472,28 +472,47 @@ lokinet_main(int argc, char* argv[])
   {
     // when we have an explicit filepath
     fs::path basedir = configFile->parent_path();
-
     if (genconfigOnly)
     {
-      llarp::ensureConfig(basedir, *configFile, overwrite, opts.isRouter);
+      try
+      {
+        llarp::ensureConfig(basedir, *configFile, overwrite, opts.isRouter);
+      }
+      catch (std::exception& ex)
+      {
+        LogError("cannot generate config at ", *configFile, ": ", ex.what());
+        return 1;
+      }
     }
     else
     {
-      std::error_code ec;
-      if (!fs::exists(*configFile, ec))
+      try
       {
-        llarp::LogError("Config file not found ", *configFile);
+        if (!fs::exists(*configFile))
+        {
+          llarp::LogError("Config file not found ", *configFile);
+          return 1;
+        }
+      }
+      catch (std::exception& ex)
+      {
+        LogError("cannot check if ", *configFile, " exists: ", ex.what());
         return 1;
       }
-
-      if (ec)
-        throw std::runtime_error(llarp::stringify("filesystem error: ", ec));
     }
   }
   else
   {
-    llarp::ensureConfig(
-        llarp::GetDefaultDataDir(), llarp::GetDefaultConfigPath(), overwrite, opts.isRouter);
+    try
+    {
+      llarp::ensureConfig(
+          llarp::GetDefaultDataDir(), llarp::GetDefaultConfigPath(), overwrite, opts.isRouter);
+    }
+    catch (std::exception& ex)
+    {
+      llarp::LogError("cannot ensure config: ", ex.what());
+      return 1;
+    }
     configFile = llarp::GetDefaultConfigPath();
   }
 

llarp/config/config.cpp

@@ -107,6 +107,8 @@ namespace llarp
             "private keys.",
         },
         [this](fs::path arg) {
+          if (arg.empty())
+            throw std::invalid_argument("[router]:data-dir is empty");
           if (not fs::exists(arg))
             throw std::runtime_error(
                 stringify("Specified [router]:data-dir ", arg, " does not exist"));
@@ -981,7 +983,8 @@ namespace llarp
         });
   }
 
-  Config::Config(fs::path datadir) : m_DataDir(std::move(datadir))
+  Config::Config(fs::path datadir)
+      : m_DataDir(datadir.empty() ? fs::current_path() : std::move(datadir))
   {}
 
   constexpr auto GetOverridesDir = [](auto datadir) -> fs::path { return datadir / "conf.d"; };
@@ -1117,33 +1120,30 @@ namespace llarp
   }
 
   void
-  ensureConfig(
-      const fs::path& defaultDataDir, const fs::path& confFile, bool overwrite, bool asRouter)
+  ensureConfig(fs::path dataDir, fs::path confFile, bool overwrite, bool asRouter)
   {
-    std::error_code ec;
-
     // fail to overwrite if not instructed to do so
-    if (fs::exists(confFile, ec) && !overwrite)
+    if (fs::exists(confFile) && !overwrite)
     {
       LogDebug("Not creating config file; it already exists.");
       return;
     }
 
-    if (ec)
-      throw std::runtime_error(stringify("filesystem error: ", ec));
+    const auto parent = confFile.parent_path();
 
     // create parent dir if it doesn't exist
-    if (not fs::exists(confFile.parent_path(), ec))
+    if ((not parent.empty()) and (not fs::exists(parent)))
     {
-      if (not fs::create_directory(confFile.parent_path()))
-        throw std::runtime_error(stringify("Failed to create parent directory for ", confFile));
+      fs::create_directory(parent);
     }
-    if (ec)
-      throw std::runtime_error(stringify("filesystem error: ", ec));
 
-    llarp::LogInfo("Attempting to create config file, asRouter: ", asRouter, " path: ", confFile);
+    llarp::LogInfo(
+        "Attempting to create config file for ",
+        (asRouter ? "router" : "client"),
+        " at ",
+        confFile);
 
-    llarp::Config config{defaultDataDir};
+    llarp::Config config{dataDir};
     std::string confStr;
     if (asRouter)
       confStr = config.generateBaseRouterConfig();

llarp/config/config.hpp

@@ -247,8 +247,7 @@ namespace llarp
   };
 
   void
-  ensureConfig(
-      const fs::path& defaultDataDir, const fs::path& confFile, bool overwrite, bool asRouter);
+  ensureConfig(fs::path dataDir, fs::path confFile, bool overwrite, bool asRouter);
 
 }  // namespace llarp