feat(spurctld): scope k0s cluster to a subset of nodes

crates/spur-cli/src/k8s.rs

@@ -42,6 +42,16 @@ pub enum K8sCommand {
         /// Overrides --replicas.
         #[arg(long = "control-plane-nodes", value_delimiter = ',')]
         control_plane_nodes: Vec<String>,
+        /// Scope the cluster to a subset of nodes (hostlist, e.g. "gpu[01-08]"). Combined with
+        /// --partition/--selector as a union; empty = enroll the whole inventory.
+        #[arg(long)]
+        nodes: Option<String>,
+        /// Scope the cluster to a partition's nodes.
+        #[arg(long)]
+        partition: Option<String>,
+        /// Scope the cluster to nodes matching every key=value label (repeatable).
+        #[arg(long = "selector", value_parser = parse_key_val)]
+        selector: Vec<(String, String)>,
     },
     /// Tear the k0s cluster down.
     Down {
@@ -88,12 +98,18 @@ pub async fn main_with_args(args: Vec<String>) -> Result<()> {
             control_plane_node,
             replicas,
             control_plane_nodes,
+            nodes,
+            partition,
+            selector,
         } => {
             cmd_up(
                 &controller,
                 control_plane_node,
                 replicas,
                 control_plane_nodes,
+                nodes,
+                partition,
+                selector,
             )
             .await
         }
@@ -112,6 +128,16 @@ fn effective_user() -> String {
     whoami::username().unwrap_or_else(|_| "unknown".into())
 }
 
+fn parse_key_val(s: &str) -> Result<(String, String), String> {
+    let (k, v) = s
+        .split_once('=')
+        .ok_or_else(|| format!("expected key=value, got {s}"))?;
+    if k.is_empty() {
+        return Err(format!("empty selector key in {s}"));
+    }
+    Ok((k.to_string(), v.to_string()))
+}
+
 async fn cmd_install_k0s(version: &str, path: &str, force: bool) -> Result<()> {
     let dest = std::path::Path::new(path);
     if dest.exists() && !force {
@@ -130,11 +156,15 @@ async fn cmd_install_k0s(version: &str, path: &str, force: bool) -> Result<()> {
     Ok(())
 }
 
+#[allow(clippy::too_many_arguments)]
 async fn cmd_up(
     controller: &str,
     control_plane_node: Option<String>,
     replicas: Option<u32>,
     control_plane_nodes: Vec<String>,
+    nodes: Option<String>,
+    partition: Option<String>,
+    selector: Vec<(String, String)>,
 ) -> Result<()> {
     let mut client = SlurmControllerClient::new(spur_client::connect_channel(controller).await?);
     let resp = client
@@ -143,6 +173,9 @@ async fn cmd_up(
             control_plane_replicas: replicas,
             control_plane_nodes,
             caller: effective_user(),
+            nodes: nodes.unwrap_or_default(),
+            partition: partition.unwrap_or_default(),
+            selector: selector.into_iter().collect(),
         })
         .await?
         .into_inner();
@@ -186,6 +219,11 @@ async fn cmd_status(controller: &str) -> Result<()> {
     } else if !resp.control_plane_node.is_empty() {
         println!("control-plane: {}", resp.control_plane_node);
     }
+    if resp.member_nodes.is_empty() {
+        println!("members: all nodes");
+    } else {
+        println!("members: {}", resp.member_nodes.join(", "));
+    }
     for n in resp.nodes {
         println!(
             "  {:<24} {:<11} {:<11} enabled={}",
@@ -223,6 +261,7 @@ mod tests {
                 control_plane_node,
                 replicas,
                 control_plane_nodes,
+                ..
             } => {
                 assert_eq!(control_plane_node.as_deref(), Some("head-node"));
                 assert_eq!(replicas, None);
@@ -232,6 +271,47 @@ mod tests {
         }
     }
 
+    #[test]
+    fn parses_up_with_node_scope_flags() {
+        let args = K8sArgs::try_parse_from([
+            "k8s",
+            "up",
+            "--nodes",
+            "gpu[01-08]",
+            "--partition",
+            "batch",
+            "--selector",
+            "zone=z1",
+            "--selector",
+            "gpu=mi300",
+        ])
+        .unwrap();
+        match args.command {
+            K8sCommand::Up {
+                nodes,
+                partition,
+                selector,
+                ..
+            } => {
+                assert_eq!(nodes.as_deref(), Some("gpu[01-08]"));
+                assert_eq!(partition.as_deref(), Some("batch"));
+                assert_eq!(
+                    selector,
+                    vec![
+                        ("zone".to_string(), "z1".to_string()),
+                        ("gpu".to_string(), "mi300".to_string())
+                    ]
+                );
+            }
+            _ => panic!("wrong command"),
+        }
+    }
+
+    #[test]
+    fn selector_without_equals_is_rejected() {
+        assert!(K8sArgs::try_parse_from(["k8s", "up", "--selector", "bogus"]).is_err());
+    }
+
     #[test]
     fn parses_up_with_replicas_and_node_set() {
         let args = K8sArgs::try_parse_from(["k8s", "up", "--replicas", "3"]).unwrap();

crates/spur-core/src/k0s.rs

@@ -125,7 +125,7 @@ mod cluster_state_tests {
             phase: K0sPhase::Ready,
             control_plane_node: Some("cp-1".into()),
             control_plane_nodes: vec!["cp-1".into(), "cp-2".into(), "cp-3".into()],
-            reset_requested: false,
+            ..Default::default()
         };
         assert_eq!(st.controllers(), vec!["cp-1", "cp-2", "cp-3"]);
         assert_eq!(st.bootstrap().as_deref(), Some("cp-1"));
@@ -135,9 +135,8 @@ mod cluster_state_tests {
     fn bootstrap_falls_back_to_first_of_set_when_singular_absent() {
         let st = K0sClusterState {
             phase: K0sPhase::Ready,
-            control_plane_node: None,
             control_plane_nodes: vec!["cp-1".into(), "cp-2".into(), "cp-3".into()],
-            reset_requested: false,
+            ..Default::default()
         };
         assert_eq!(st.bootstrap().as_deref(), Some("cp-1"));
     }
@@ -146,6 +145,23 @@ mod cluster_state_tests {
     fn controllers_empty_when_down() {
         assert!(K0sClusterState::default().controllers().is_empty());
     }
+
+    #[test]
+    fn is_member_empty_scope_matches_all() {
+        let st = K0sClusterState::default();
+        assert!(st.is_member("anything"), "empty scope = whole inventory");
+    }
+
+    #[test]
+    fn is_member_respects_recorded_scope() {
+        let st = K0sClusterState {
+            member_nodes: vec!["a".into(), "b".into()],
+            ..Default::default()
+        };
+        assert!(st.is_member("a"));
+        assert!(st.is_member("b"));
+        assert!(!st.is_member("c"), "out-of-scope node excluded");
+    }
 }
 
 #[cfg(test)]
@@ -233,6 +249,9 @@ pub struct K0sClusterState {
     /// All control-plane nodes (1/3/5). Empty on pre-multi-CP state — read via [`Self::controllers`].
     #[serde(default)]
     pub control_plane_nodes: Vec<String>,
+    /// Nodes the cluster is scoped to. Empty = enroll the whole inventory (back-compat).
+    #[serde(default)]
+    pub member_nodes: Vec<String>,
     #[serde(default)]
     pub reset_requested: bool,
 }
@@ -254,4 +273,9 @@ impl K0sClusterState {
             .clone()
             .or_else(|| self.control_plane_nodes.first().cloned())
     }
+
+    /// Whether `name` is in scope for enrollment. An empty `member_nodes` means the whole inventory.
+    pub fn is_member(&self, name: &str) -> bool {
+        self.member_nodes.is_empty() || self.member_nodes.iter().any(|n| n == name)
+    }
 }

crates/spur-core/src/wal.rs

@@ -257,6 +257,8 @@ pub enum WalOperation {
         #[serde(default)]
         control_plane_nodes: Vec<String>,
         #[serde(default)]
+        member_nodes: Vec<String>,
+        #[serde(default)]
         reset_requested: bool,
     },
     NodeK0sClear {
@@ -765,6 +767,12 @@ mod deregistration_wal_tests {
             phase: K0sPhase::Ready,
             control_plane_node: Some("head-node".into()),
             control_plane_nodes: vec!["head-node".into(), "cp-2".into(), "cp-3".into()],
+            member_nodes: vec![
+                "head-node".into(),
+                "cp-2".into(),
+                "cp-3".into(),
+                "w-4".into(),
+            ],
             reset_requested: false,
         };
         let back: WalOperation =
@@ -774,11 +782,13 @@ mod deregistration_wal_tests {
                 phase,
                 control_plane_node,
                 control_plane_nodes,
+                member_nodes,
                 reset_requested,
             } => {
                 assert_eq!(phase, K0sPhase::Ready);
                 assert_eq!(control_plane_node.as_deref(), Some("head-node"));
                 assert_eq!(control_plane_nodes, vec!["head-node", "cp-2", "cp-3"]);
+                assert_eq!(member_nodes, vec!["head-node", "cp-2", "cp-3", "w-4"]);
                 assert!(!reset_requested);
             }
             _ => panic!("wrong variant"),
@@ -798,17 +808,40 @@ mod deregistration_wal_tests {
                 phase,
                 control_plane_node,
                 control_plane_nodes,
+                member_nodes,
                 reset_requested,
             } => {
                 assert_eq!(phase, K0sPhase::Ready);
                 assert_eq!(control_plane_node.as_deref(), Some("head-node"));
                 assert!(control_plane_nodes.is_empty());
+                assert!(member_nodes.is_empty());
                 assert!(!reset_requested);
             }
             _ => panic!("wrong variant"),
         }
     }
 
+    // Frozen pre-member-scope K0sSetPhase entry (has control_plane_nodes, no member_nodes); must
+    // still deserialize with member_nodes defaulting empty (= whole inventory). Never regenerate.
+    #[test]
+    fn k0s_set_phase_pre_member_scope_payload_still_deserializes() {
+        const K0S_SET_PHASE_PRE_MEMBER_SCOPE: &str = r#"{"K0sSetPhase":{"phase":"ready","control_plane_node":"head-node","control_plane_nodes":["head-node","cp-2","cp-3"],"reset_requested":false}}"#;
+        let op: WalOperation = serde_json::from_str(K0S_SET_PHASE_PRE_MEMBER_SCOPE).expect(
+            "pre-member-scope K0sSetPhase must deserialize; member_nodes needs #[serde(default)]",
+        );
+        match op {
+            WalOperation::K0sSetPhase {
+                control_plane_nodes,
+                member_nodes,
+                ..
+            } => {
+                assert_eq!(control_plane_nodes, vec!["head-node", "cp-2", "cp-3"]);
+                assert!(member_nodes.is_empty());
+            }
+            _ => panic!("wrong variant"),
+        }
+    }
+
     #[test]
     fn node_remove_none_reason_round_trips() {
         let op = WalOperation::NodeRemove {