nomad: starting client GetNode

nomad/client_endpoint.go

@@ -105,3 +105,37 @@ func (c *Client) UpdateStatus(args *structs.UpdateStatusRequest, reply *structs.
 	reply.Index = index
 	return nil
 }
+
+// GetNode is used to request information about a specific ndoe
+func (c *Client) GetNode(args *structs.NodeSpecificRequest,
+	reply *structs.SingleNodeResponse) error {
+	if done, err := c.srv.forward("Client.GetNode", args, args, reply); done {
+		return err
+	}
+	defer metrics.MeasureSince([]string{"nomad", "client", "get_node"}, time.Now())
+
+	// Verify the arguments
+	if args.NodeID == "" {
+		return fmt.Errorf("missing node ID")
+	}
+
+	// Look for the node
+	state := c.srv.fsm.State()
+	out, err := state.GetNodeByID(args.NodeID)
+	if err != nil {
+		return err
+	}
+
+	// Setup the output
+	if out != nil {
+		reply.Node = out
+		reply.Index = out.ModifyIndex
+	} else {
+		// TODO: Fix table index
+		reply.Index = 0
+	}
+
+	// Set the query response
+	c.srv.setQueryMeta(&reply.QueryMeta)
+	return nil
+}

nomad/rpc.go

@@ -254,3 +254,14 @@ func (s *Server) raftApply(t structs.MessageType, msg interface{}) (interface{},
 
 	return future.Response(), future.Index(), nil
 }
+
+// setQueryMeta is used to populate the QueryMeta data for an RPC call
+func (s *Server) setQueryMeta(m *structs.QueryMeta) {
+	if s.IsLeader() {
+		m.LastContact = 0
+		m.KnownLeader = true
+	} else {
+		m.LastContact = time.Now().Sub(s.raft.LastContact())
+		m.KnownLeader = (s.raft.Leader() != "")
+	}
+}

nomad/structs/structs.go

@@ -130,12 +130,24 @@ type UpdateStatusRequest struct {
 	WriteRequest
 }
 
+// NodeSpecificRequest is used when we just need to specify a target node
+type NodeSpecificRequest struct {
+	NodeID string
+	WriteRequest
+}
+
 // GenericResponse is used to respond to a request where no
 // specific response information is needed.
 type GenericResponse struct {
 	WriteMeta
 }
 
+// SingleNodeResponse is used to return a single node
+type SingleNodeResponse struct {
+	Node *Node
+	QueryMeta
+}
+
 const (
 	NodeStatusInit  = "initializing"
 	NodeStatusReady = "ready"