From fa2cbb6f0cf9cc71e1b51ff62af25c59da0fd742 Mon Sep 17 00:00:00 2001
From: Diptanu Choudhury <diptanuc@gmail.com>
Date: Wed, 25 Oct 2017 23:51:53 -0700
Subject: [PATCH] Added the purge API on node endpoints

---
 command/agent/node_endpoint.go      | 19 +++++++++
 command/agent/node_endpoint_test.go | 65 +++++++++++++++++++++++++++++
 nomad/node_endpoint.go              | 15 ++++++-
 3 files changed, 98 insertions(+), 1 deletion(-)

diff --git a/command/agent/node_endpoint.go b/command/agent/node_endpoint.go
index 8720503c5..5c173346c 100644
--- a/command/agent/node_endpoint.go
+++ b/command/agent/node_endpoint.go
@@ -42,6 +42,9 @@ func (s *HTTPServer) NodeSpecificRequest(resp http.ResponseWriter, req *http.Req
 	case strings.HasSuffix(path, "/drain"):
 		nodeName := strings.TrimSuffix(path, "/drain")
 		return s.nodeToggleDrain(resp, req, nodeName)
+	case strings.HasSuffix(path, "/purge"):
+		nodeName := strings.TrimSuffix(path, "/purge")
+		return s.nodePurge(resp, req, nodeName)
 	default:
 		return s.nodeQuery(resp, req, path)
 	}
@@ -142,3 +145,19 @@ func (s *HTTPServer) nodeQuery(resp http.ResponseWriter, req *http.Request,
 	}
 	return out.Node, nil
 }
+
+func (s *HTTPServer) nodePurge(resp http.ResponseWriter, req *http.Request, nodeID string) (interface{}, error) {
+	if req.Method != "POST" {
+		return nil, CodedError(405, ErrInvalidMethod)
+	}
+	args := structs.NodeDeregisterRequest{
+		NodeID: nodeID,
+	}
+	s.parseWriteRequest(req, &args.WriteRequest)
+	var out structs.NodeUpdateResponse
+	if err := s.agent.RPC("Node.Deregister", &args, &out); err != nil {
+		return nil, err
+	}
+	setIndex(resp, out.Index)
+	return out, nil
+}
diff --git a/command/agent/node_endpoint_test.go b/command/agent/node_endpoint_test.go
index 391c10b9d..9f8a1edad 100644
--- a/command/agent/node_endpoint_test.go
+++ b/command/agent/node_endpoint_test.go
@@ -276,6 +276,71 @@ func TestHTTP_NodeDrain(t *testing.T) {
 	})
 }
 
+func TestHTTP_NodePurge(t *testing.T) {
+	t.Parallel()
+	httpTest(t, nil, func(s *TestAgent) {
+		// Create the node
+		node := mock.Node()
+		args := structs.NodeRegisterRequest{
+			Node:         node,
+			WriteRequest: structs.WriteRequest{Region: "global"},
+		}
+		var resp structs.NodeUpdateResponse
+		if err := s.Agent.RPC("Node.Register", &args, &resp); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// Add some allocations to the node
+		state := s.Agent.server.State()
+		alloc1 := mock.Alloc()
+		alloc1.NodeID = node.ID
+		if err := state.UpsertJobSummary(999, mock.JobSummary(alloc1.JobID)); err != nil {
+			t.Fatal(err)
+		}
+		err := state.UpsertAllocs(1000, []*structs.Allocation{alloc1})
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// Make the HTTP request to purge it
+		req, err := http.NewRequest("POST", "/v1/node/"+node.ID+"/purge", nil)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		respW := httptest.NewRecorder()
+
+		// Make the request
+		obj, err := s.Server.NodeSpecificRequest(respW, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// Check for the index
+		if respW.HeaderMap.Get("X-Nomad-Index") == "" {
+			t.Fatalf("missing index")
+		}
+
+		// Check the response
+		upd := obj.(structs.NodeUpdateResponse)
+		if len(upd.EvalIDs) == 0 {
+			t.Fatalf("bad: %v", upd)
+		}
+
+		// Ensure that the node is not present anymore
+		args1 := structs.NodeSpecificRequest{
+			NodeID:       node.ID,
+			QueryOptions: structs.QueryOptions{Region: "global"},
+		}
+		var resp1 structs.SingleNodeResponse
+		if err := s.Agent.RPC("Node.GetNode", &args1, &resp1); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		if resp1.Node != nil {
+			t.Fatalf("node still exists after purging: %#v", resp1.Node)
+		}
+	})
+}
+
 func TestHTTP_NodeQuery(t *testing.T) {
 	t.Parallel()
 	httpTest(t, nil, func(s *TestAgent) {
diff --git a/nomad/node_endpoint.go b/nomad/node_endpoint.go
index a8778216f..a62c68d1b 100644
--- a/nomad/node_endpoint.go
+++ b/nomad/node_endpoint.go
@@ -213,6 +213,20 @@ func (n *Node) Deregister(args *structs.NodeDeregisterRequest, reply *structs.No
 	if args.NodeID == "" {
 		return fmt.Errorf("missing node ID for client deregistration")
 	}
+	// Look for the node
+	snap, err := n.srv.fsm.State().Snapshot()
+	if err != nil {
+		return err
+	}
+
+	ws := memdb.NewWatchSet()
+	node, err := snap.NodeByID(ws, args.NodeID)
+	if err != nil {
+		return err
+	}
+	if node == nil {
+		return fmt.Errorf("node not found")
+	}
 
 	// Commit this update via Raft
 	_, index, err := n.srv.raftApply(structs.NodeDeregisterRequestType, args)
@@ -232,7 +246,6 @@ func (n *Node) Deregister(args *structs.NodeDeregisterRequest, reply *structs.No
 	}
 
 	// Determine if there are any Vault accessors on the node
-	ws := memdb.NewWatchSet()
 	accessors, err := n.srv.State().VaultAccessorsByNode(ws, args.NodeID)
 	if err != nil {
 		n.srv.logger.Printf("[ERR] nomad.client: looking up accessors for node %q failed: %v", args.NodeID, err)