fix: rename std log target to stderr (ThinkParQ/beegfs-rs#181)

And clarify what they mean in the config template.

Keep std setting around hidden as an alias for stderr.

Author: rustybee42

mgmtd/assets/beegfs-mgmtd.toml

@@ -11,7 +11,9 @@
 # Managements database file location.
 # db-file = "/var/lib/beegfs/mgmtd.sqlite"
 
-# The log target to use (valid are "journald", "std").
+# The log target to use. Valid options are:
+#   "journald": Log to the systemd journal
+#   "stderr": Log to the standard error output
 # log-target = "journald"
 
 # The log level to use (valid are "error", "warn", "info", "debug", "trace").

mgmtd/src/config.rs

@@ -511,8 +511,10 @@ const fn version_str() -> &'static str {
 #[derive(Clone, Debug, ValueEnum, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub enum LogTarget {
-    Std,
     Journald,
+    #[value(alias("std"))]
+    #[serde(alias = "std")]
+    Stderr,
 }
 
 /// Defines the log level

mgmtd/src/main.rs

@@ -46,7 +46,7 @@ fn inner_main() -> Result<()> {
 
     // Initialize logging
     match user_config.log_target {
-        LogTarget::Std => Ok(env_logger::Builder::from_env(
+        LogTarget::Stderr => Ok(env_logger::Builder::from_env(
             env_logger::Env::default()
                 .default_filter_or(LevelFilter::from(user_config.log_level.clone()).as_str()),
         )