From c57e760933fec52690e38cc018fa38f94862a2c4 Mon Sep 17 00:00:00 2001
From: Drew Bailey <2614075+drewbailey@users.noreply.github.com>
Date: Thu, 15 Oct 2020 16:44:36 -0400
Subject: [PATCH] remove special node drain event type

rely on standardized events instead of special node drain event
---
 nomad/state/events.go           |  9 +------
 nomad/state/node_events.go      | 48 ---------------------------------
 nomad/state/node_events_test.go |  2 +-
 nomad/state/state_changes.go    |  2 --
 4 files changed, 2 insertions(+), 59 deletions(-)

diff --git a/nomad/state/events.go b/nomad/state/events.go
index a5a65a02b..b9884a085 100644
--- a/nomad/state/events.go
+++ b/nomad/state/events.go
@@ -51,14 +51,6 @@ type NodeEvent struct {
 	Node *structs.Node
 }
 
-// NNodeDrainEvent is the Payload for a NodeDrain event. It contains
-// information related to the Node being drained as well as high level
-// information about the current allocations on the Node
-type NodeDrainEvent struct {
-	Node      *structs.Node
-	JobAllocs map[string]*JobDrainDetails
-}
-
 type NodeDrainAllocDetails struct {
 	ID      string
 	Migrate *structs.MigrateStrategy
@@ -81,6 +73,7 @@ var MsgTypeEvents = map[structs.MessageType]string{
 	structs.JobBatchDeregisterRequestType:           TypeJobBatchDeregistered,
 	structs.AllocUpdateDesiredTransitionRequestType: TypeAllocUpdateDesiredStatus,
 	structs.NodeUpdateEligibilityRequestType:        TypeNodeDrain,
+	structs.NodeUpdateDrainRequestType:              TypeNodeDrain,
 	structs.BatchNodeUpdateDrainRequestType:         TypeNodeDrain,
 	structs.DeploymentStatusUpdateRequestType:       TypeDeploymentUpdate,
 	structs.DeploymentPromoteRequestType:            TypeDeploymentPromotion,
diff --git a/nomad/state/node_events.go b/nomad/state/node_events.go
index 178262fb9..2bfc439e7 100644
--- a/nomad/state/node_events.go
+++ b/nomad/state/node_events.go
@@ -32,51 +32,3 @@ func NodeDeregisterEventFromChanges(tx ReadTxn, changes Changes) (*structs.Event
 	}
 	return &structs.Events{Index: changes.Index, Events: events}, nil
 }
-
-func NodeDrainEventFromChanges(tx ReadTxn, changes Changes) (*structs.Events, error) {
-	var events []structs.Event
-	for _, change := range changes.Changes {
-		switch change.Table {
-		case "nodes":
-			after, ok := change.After.(*structs.Node)
-			if !ok {
-				return nil, fmt.Errorf("transaction change was not a Node")
-			}
-
-			// retrieve allocations currently on node
-			allocs, err := allocsByNodeTxn(tx, nil, after.ID)
-			if err != nil {
-				return nil, fmt.Errorf("retrieving allocations for node drain event: %w", err)
-			}
-
-			// build job/alloc details for node drain
-			jobAllocs := make(map[string]*JobDrainDetails)
-			for _, a := range allocs {
-				if _, ok := jobAllocs[a.Job.Name]; !ok {
-					jobAllocs[a.Job.Name] = &JobDrainDetails{
-						AllocDetails: make(map[string]NodeDrainAllocDetails),
-						Type:         a.Job.Type,
-					}
-				}
-
-				jobAllocs[a.Job.Name].AllocDetails[a.ID] = NodeDrainAllocDetails{
-					Migrate: a.MigrateStrategy(),
-					ID:      a.ID,
-				}
-			}
-
-			event := structs.Event{
-				Topic: structs.TopicNode,
-				Type:  TypeNodeDrain,
-				Index: changes.Index,
-				Key:   after.ID,
-				Payload: &NodeDrainEvent{
-					Node:      after,
-					JobAllocs: jobAllocs,
-				},
-			}
-			events = append(events, event)
-		}
-	}
-	return &structs.Events{Index: changes.Index, Events: events}, nil
-}
diff --git a/nomad/state/node_events_test.go b/nomad/state/node_events_test.go
index 2789ae80f..597f66626 100644
--- a/nomad/state/node_events_test.go
+++ b/nomad/state/node_events_test.go
@@ -255,7 +255,7 @@ func TestNodeDrainEventFromChanges(t *testing.T) {
 	require.Equal(t, TypeNodeDrain, got.Events[0].Type)
 	require.Equal(t, uint64(100), got.Events[0].Index)
 
-	nodeEvent, ok := got.Events[0].Payload.(*NodeDrainEvent)
+	nodeEvent, ok := got.Events[0].Payload.(*NodeEvent)
 	require.True(t, ok)
 
 	require.Equal(t, structs.NodeSchedulingIneligible, nodeEvent.Node.SchedulingEligibility)
diff --git a/nomad/state/state_changes.go b/nomad/state/state_changes.go
index c7a2d9634..fa4c27a7b 100644
--- a/nomad/state/state_changes.go
+++ b/nomad/state/state_changes.go
@@ -188,8 +188,6 @@ func processDBChanges(tx ReadTxn, changes Changes) (*structs.Events, error) {
 		return nil, nil
 	case structs.NodeDeregisterRequestType:
 		return NodeDeregisterEventFromChanges(tx, changes)
-	case structs.NodeUpdateDrainRequestType:
-		return NodeDrainEventFromChanges(tx, changes)
 	default:
 		return GenericEventsFromChanges(tx, changes)
 	}