Additional logging for ConfigError

src/config.rs

@@ -79,13 +79,15 @@ fn get_default_config() -> Config {
 
 #[derive(Debug)]
 pub struct ConfigError {
-    description: String
+    description: String,
+    original_error: Option<Box<Error>>
 }
 
 impl ConfigError {
-    fn new(description: &str) -> ConfigError {
+    fn new(description: &str, original_error: Option<Box<Error>>) -> ConfigError {
         ConfigError {
-            description: String::from(description)
+            description: String::from(description),
+            original_error
         }
     }
 }
@@ -94,15 +96,19 @@ impl Error for ConfigError {}
 
 impl fmt::Display for ConfigError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "Configuration Error: {}", self.description)
+        match &self.original_error {
+            Some(original_error) => {
+                write!(f, "{}: \"{}\"", self.description, original_error)
+            },
+            None => write!(f, "{}", self.description)
+        }
     }
 }
 
 fn read_config(yaml_str: &str) -> Result<Config, ConfigError> {
     match serde_yaml::from_str(yaml_str) {
         Ok(v) => Result::Ok(v),
-        // File wasn't valid Config/YAML
-        Err(_e) => Result::Err(ConfigError::new("Configuration file was invalid"))
+        Err(e) => Result::Err(ConfigError::new("Invalid Configuration", Option::Some(Box::from(e))))
     }
 }
 
@@ -115,15 +121,12 @@ pub fn load_config(path: &str) -> Result<Config, ConfigError> {
                     if c > 0 {
                         read_config(&contents)
                     } else {
-                        // File was empty
-                        Result::Err(ConfigError::new("Configuration file was empty"))
+                        Result::Err(ConfigError::new("Empty Configuration File", Option::None))
                     }
                 },
-                // File couldn't be read
-                Err(_e) => Result::Err(ConfigError::new("Configuration file could not be read"))
+                Err(e) => Result::Err(ConfigError::new("Cannot Read Configuration File", Option::Some(Box::from(e))))
             }
         },
-        // File Doesn't exist
-        Err(_e) => Result::Err(ConfigError::new(&format!("Configuration file doesn't exist \"{}\"", path)))
+        Err(e) => Result::Err(ConfigError::new(&format!("Configuration File Doesn't Exist \"{}\"", path), Option::Some(Box::from(e))))
     }
 }

src/main.rs

@@ -74,7 +74,10 @@ fn main() {
 
     let config_path: &str = args.value_of("config").unwrap_or("/etc/rsddns/rsddns.yml");
     let config = match config::load_config(config_path) {
-        Ok(c) => Option::Some(c),
+        Ok(c) => {
+            info!("Loaded configuration from \"{}\"", config_path);
+            Option::Some(c)
+        },
         Err(e) => {
             error!("{}", e);
             Option::None