From 09fd05bd8fdce405c06e0cd6e390bd1b05dcf20f Mon Sep 17 00:00:00 2001
From: Lang Martin <lang@hashicorp.com>
Date: Fri, 7 Jun 2019 11:25:55 -0400
Subject: [PATCH] node_endpoint raft store then shutdown, test deprecation

---
 nomad/node_endpoint.go      | 36 +++++++++++++++++---------------
 nomad/node_endpoint_test.go | 41 +++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 16 deletions(-)

diff --git a/nomad/node_endpoint.go b/nomad/node_endpoint.go
index 7459f83d7..cc0965e49 100644
--- a/nomad/node_endpoint.go
+++ b/nomad/node_endpoint.go
@@ -261,8 +261,14 @@ func (n *Node) Deregister(args *structs.NodeDeregisterRequest, reply *structs.No
 	}
 
 	// Verify the arguments
+	var nodeIDs []string
 	if len(args.NodeIDs) == 0 {
-		return fmt.Errorf("missing node IDs for client deregistration")
+		if args.NodeID == "" {
+			return fmt.Errorf("missing node IDs for client deregistration")
+		}
+		nodeIDs = append(nodeIDs, args.NodeID)
+	} else if args.NodeID != "" {
+		return fmt.Errorf("use only NodeIDs, the NodeID field is deprecated")
 	}
 
 	// Open state handles
@@ -273,8 +279,8 @@ func (n *Node) Deregister(args *structs.NodeDeregisterRequest, reply *structs.No
 
 	ws := memdb.NewWatchSet()
 
-	for _, nodeID := range args.NodeIDs {
-		// Look for the node
+	// Assert that the state contains the nodes
+	for _, nodeID := range nodeIDs {
 		node, err := snap.NodeByID(ws, nodeID)
 		if err != nil {
 			return fmt.Errorf("node lookup failed: %s: %v", nodeID, err)
@@ -282,8 +288,17 @@ func (n *Node) Deregister(args *structs.NodeDeregisterRequest, reply *structs.No
 		if node == nil {
 			return fmt.Errorf("node not found: %s", nodeID)
 		}
+	}
 
-		// Clear the heartbeat timer if any
+	// Commit this update to Raft, before we clear the heartbeatTimer so that failure
+	// leaves the node running
+	_, index, err := n.srv.raftApply(structs.NodeDeregisterRequestType, args)
+	if err != nil {
+		n.logger.Error("deregister failed", "error", err)
+		return err
+	}
+
+	for _, nodeID := range nodeIDs {
 		n.srv.clearHeartbeatTimer(nodeID)
 
 		// If there are any Vault accessors on the node, revoke them
@@ -300,19 +315,8 @@ func (n *Node) Deregister(args *structs.NodeDeregisterRequest, reply *structs.No
 				return err
 			}
 		}
-	}
 
-	// Commit this update via Raft
-	_, index, err := n.srv.raftApply(structs.NodeDeregisterRequestType, args)
-	if err != nil {
-		n.logger.Error("deregister failed", "error", err)
-		return err
-	}
-
-	// Create the evaluations for these nodes
-	for _, nodeID := range args.NodeIDs {
-		// QUESTION createNodeEvals opens it's own state and watch handles, does
-		// that break atomicity?
+		// Create the evaluations for these nodes
 		evalIDs, evalIndex, err := n.createNodeEvals(nodeID, index)
 		if err != nil {
 			n.logger.Error("eval creation failed", "error", err)
diff --git a/nomad/node_endpoint_test.go b/nomad/node_endpoint_test.go
index 29ec2cc0f..84642d662 100644
--- a/nomad/node_endpoint_test.go
+++ b/nomad/node_endpoint_test.go
@@ -246,6 +246,47 @@ func TestClientEndpoint_Deregister(t *testing.T) {
 	}
 }
 
+func TestClientEndpoint_DeregisterDeprecatedField(t *testing.T) {
+	t.Parallel()
+	s1 := TestServer(t, nil)
+	defer s1.Shutdown()
+	codec := rpcClient(t, s1)
+	testutil.WaitForLeader(t, s1.RPC)
+
+	// Create the register request
+	node := mock.Node()
+	reg := &structs.NodeRegisterRequest{
+		Node:         node,
+		WriteRequest: structs.WriteRequest{Region: "global"},
+	}
+
+	// Fetch the response
+	var resp structs.GenericResponse
+	require.NoError(t, msgpackrpc.CallWithCodec(codec, "Node.Register", reg, &resp))
+
+	// Deregister fails, because the DeregisterRequest should use only the batch field
+	dereg := &structs.NodeDeregisterRequest{
+		NodeID:       "foo",
+		NodeIDs:      []string{node.ID},
+		WriteRequest: structs.WriteRequest{Region: "global"},
+	}
+	require.Error(t, msgpackrpc.CallWithCodec(codec, "Node.Deregister", dereg, &resp))
+
+	// Deregister succeeds using the pre-0.9.3 single node request
+	dereg = &structs.NodeDeregisterRequest{
+		NodeID:       node.ID,
+		WriteRequest: structs.WriteRequest{Region: "global"},
+	}
+	require.NoError(t, msgpackrpc.CallWithCodec(codec, "Node.Deregister", dereg, &resp))
+
+	// Check for the node in the FSM
+	state := s1.fsm.State()
+	ws := memdb.NewWatchSet()
+	out, err := state.NodeByID(ws, node.ID)
+	require.NoError(t, err)
+	require.Nil(t, out)
+}
+
 func TestClientEndpoint_Deregister_ACL(t *testing.T) {
 	t.Parallel()
 	s1, root := TestACLServer(t, nil)