better testing of scaling parsing, fixed some broken tests by api

changes

jobspec/parse_test.go

@@ -1320,7 +1320,7 @@ func TestParse(t *testing.T) {
 						Name: helper.StringToPtr("group"),
 						Scaling: &api.ScalingPolicy{
 							Min: helper.Int64ToPtr(5),
-							Max: 100,
+							Max: helper.Int64ToPtr(100),
 							Policy: map[string]interface{}{
 								"foo": "bar",
 								"b":   true,
@@ -1345,7 +1345,7 @@ func TestParse(t *testing.T) {
 						Name: helper.StringToPtr("group"),
 						Scaling: &api.ScalingPolicy{
 							Min:     nil,
-							Max:     0,
+							Max:     helper.Int64ToPtr(10),
 							Policy:  nil,
 							Enabled: nil,
 						},
@@ -1355,6 +1355,12 @@ func TestParse(t *testing.T) {
 			false,
 		},
 
+		{
+			"tg-scaling-policy-missing-max.hcl",
+			nil,
+			true,
+		},
+
 		{
 			"tg-scaling-policy-multi-policy.hcl",
 			nil,

jobspec/test-fixtures/tg-scaling-policy-minimal.hcl

@@ -1,5 +1,7 @@
 job "elastic" {
   group "group" {
-    scaling {}
+    scaling {
+      max = 10
+    }
   }
 }

jobspec/test-fixtures/tg-scaling-policy-missing-max.hcl

@@ -0,0 +1,7 @@
+job "elastic" {
+  group "group" {
+    scaling {
+      // required: max = ...
+    }
+  }
+}

nomad/structs/structs.go

@@ -5952,12 +5952,15 @@ func (tg *TaskGroup) validateScalingPolicy(j *Job) error {
 	if tg.Scaling.Max < 0 {
 		mErr.Errors = append(mErr.Errors,
 			fmt.Errorf("Scaling policy invalid: maximum count must be specified and non-negative"))
-	} else if tg.Scaling.Max < tg.Scaling.Min {
-		mErr.Errors = append(mErr.Errors,
-			fmt.Errorf("Scaling policy invalid: maximum count must not be less than minimum count"))
-	} else if tg.Scaling.Max < int64(tg.Count) {
-		mErr.Errors = append(mErr.Errors,
-			fmt.Errorf("Scaling policy invalid: task group count must not be greater than maximum count in scaling policy"))
+	} else {
+		if tg.Scaling.Max < tg.Scaling.Min {
+			mErr.Errors = append(mErr.Errors,
+				fmt.Errorf("Scaling policy invalid: maximum count must not be less than minimum count"))
+		}
+		if tg.Scaling.Max < int64(tg.Count) {
+			mErr.Errors = append(mErr.Errors,
+				fmt.Errorf("Scaling policy invalid: task group count must not be greater than maximum count in scaling policy"))
+		}
 	}
 
 	if int64(tg.Count) < tg.Scaling.Min && !(j.IsMultiregion() && tg.Count == 0 && j.Region == "global") {