fix(reflectors): retain responsive peers on partial reselection

src/reflector_selector.rs

@@ -252,17 +252,21 @@ impl ReflectorSelector {
                 candidates.swap(i, j);
             }
 
-            if (candidates.len() as u8) < num_reflectors {
-                info!(
-                    "Only {} usable reflectors, retaining current set of {}",
-                    candidates.len(),
-                    num_reflectors
-                );
+            if candidates.is_empty() {
+                info!("No usable reflectors, retaining current set");
                 self.reflector_tx.send(current_peers.clone())?;
                 *reflectors_peers = current_peers;
                 continue;
             }
 
+            if (candidates.len() as u8) < num_reflectors {
+                info!(
+                    "Only {} usable reflectors, selecting available candidates",
+                    candidates.len()
+                );
+            }
+            let num_reflectors = num_reflectors.min(candidates.len() as u8);
+
             let mut new_peers = Vec::new();
             for i in 0..num_reflectors {
                 let peer = candidates[i as usize].0;

src/settings/mod.rs

@@ -200,7 +200,14 @@ impl Settings {
             config::File::with_name("/etc/sqm-autorate-rust/config.toml").required(false),
         );
 
-        let builder = builder.add_source(Environment::with_prefix("SQMA").separator("__"));
+        let builder = builder.add_source(
+            Environment::with_prefix("SQMA")
+                .separator("__")
+                .try_parsing(true)
+                .list_separator(",")
+                .with_list_parse_key("reflectors.files")
+                .with_list_parse_key("reflectors.countries"),
+        );
         let mut settings: Self = builder.build()?.try_deserialize()?;
 
         settings.reflectors.load_files()?;

src/settings/validation.rs

@@ -212,6 +212,15 @@ impl ReflectorSettings {
             );
         }
 
+        for (index, reflector) in self.entries.iter().enumerate() {
+            if reflector.protocols.is_empty() {
+                report.error(
+                    "reflectors.entries",
+                    format!("entry {index} must have at least one measurement protocol"),
+                );
+            }
+        }
+
         for (index, file) in self.files.iter().enumerate() {
             if file.trim().is_empty() {
                 report.error(