feat(resources): typed nodes on base resources

src/config.rs

@@ -461,6 +461,8 @@ pub struct Resources {
     pub cpus: u32,
     pub mem: String,
     pub time: String,
+    /// `--nodes`. Defaults to 1 when unset, which emits no directive at all.
+    pub nodes: Option<u32>,
     pub partition: Option<String>,
     pub qos: Option<String>,
     pub account: Option<String>,
@@ -469,8 +471,8 @@ pub struct Resources {
     /// waiting for SLURM's drain detection.
     pub exclude_nodes: Option<String>,
     /// Escape hatch for sbatch directives the typed schema doesn't cover
-    /// (e.g. `--array`, `--nodes`, `--mail-type`, `--gpu-bind`). Each entry
-    /// is rendered verbatim as a separate `#SBATCH` line, *after* the
+    /// (e.g. `--array`, `--mail-type`, `--gpu-bind`). Each entry is
+    /// rendered verbatim as a separate `#SBATCH` line, *after* the
     /// typed directives. Use this only for things labctl can't model —
     /// don't override `--cpus-per-task` or `--time` here, those have
     /// dedicated fields and overriding them confuses the dispatcher.
@@ -518,6 +520,7 @@ impl Default for Resources {
             cpus: 1,
             mem: "4GB".to_string(),
             time: "00:10:00".to_string(),
+            nodes: None,
             partition: None,
             qos: None,
             account: None,

src/runner.rs

@@ -1583,6 +1583,9 @@ fn render_script(
         if let Some(qos) = recipe.resources.qos.as_ref().or(cluster.slurm.qos.as_ref()) {
             script.push_str(&format!("#SBATCH --qos={qos}\n"));
         }
+        if let Some(nodes) = recipe.resources.nodes {
+            script.push_str(&format!("#SBATCH --nodes={nodes}\n"));
+        }
         if let Some(exclude) = recipe.resources.exclude_nodes.as_ref() {
             script.push_str(&format!("#SBATCH --exclude={exclude}\n"));
         }
@@ -2115,6 +2118,41 @@ time = "12:00:00"
         );
     }
 
+    #[test]
+    fn base_resources_nodes_is_typed() {
+        let script = render(&format!("{BASE}nodes = 2\n"));
+        assert!(
+            script.contains("#SBATCH --nodes=2"),
+            "base nodes missing:\n{script}"
+        );
+        // Unset stays unset, so existing recipes render unchanged.
+        let plain = render(BASE);
+        assert!(
+            !plain.contains("#SBATCH --nodes"),
+            "unset nodes must not emit a directive:\n{plain}"
+        );
+    }
+
+    #[test]
+    fn base_and_component_nodes_are_independent() {
+        let script = render(&format!(
+            "{BASE}nodes = 2\n\n[[resources.components]]\ngpus = 4\ncpus = 16\nmem = \"128GB\"\nnodes = 1\n"
+        ));
+        assert!(
+            script.contains("#SBATCH --nodes=2"),
+            "fleet nodes:\n{script}"
+        );
+        assert!(
+            script.contains("#SBATCH --nodes=1"),
+            "trainer nodes:\n{script}"
+        );
+        assert_eq!(
+            script.matches("#SBATCH --nodes=").count(),
+            2,
+            "one per component:\n{script}"
+        );
+    }
+
     #[test]
     fn components_emit_one_separator_and_own_directives() {
         let script = render(&format!(