Adding node_pool to job key validation (#18366)

.changelog/18366.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+jobspec: add `node_pool` as a valid field
+```

api/jobs.go

@@ -966,7 +966,7 @@ type Job struct {
 	Priority         *int                    `hcl:"priority,optional"`
 	AllAtOnce        *bool                   `mapstructure:"all_at_once" hcl:"all_at_once,optional"`
 	Datacenters      []string                `hcl:"datacenters,optional"`
-	NodePool         *string                 `hcl:"node_pool,optional"`
+	NodePool         *string                 `mapstructure:"node_pool" hcl:"node_pool,optional"`
 	Constraints      []*Constraint           `hcl:"constraint,block"`
 	Affinities       []*Affinity             `hcl:"affinity,block"`
 	TaskGroups       []*TaskGroup            `hcl:"group,block"`

jobspec/parse_job.go

@@ -66,6 +66,7 @@ func parseJob(result *api.Job, list *ast.ObjectList) error {
 		"affinity",
 		"spread",
 		"datacenters",
+		"node_pool",
 		"group",
 		"id",
 		"meta",

jobspec/parse_test.go

@@ -61,6 +61,7 @@ func TestParse(t *testing.T) {
 				Datacenters: []string{"us2", "eu1"},
 				Region:      stringToPtr("fooregion"),
 				Namespace:   stringToPtr("foonamespace"),
+				NodePool:    stringToPtr("dev"),
 				ConsulToken: stringToPtr("abc"),
 				VaultToken:  stringToPtr("foo"),
 

jobspec/test-fixtures/basic.hcl

@@ -4,6 +4,7 @@
 job "binstore-storagelocker" {
   region       = "fooregion"
   namespace    = "foonamespace"
+  node_pool    = "dev"
   type         = "batch"
   priority     = 52
   all_at_once  = true