distinct_property constraint

jobspec/parse.go

@@ -412,12 +412,13 @@ func parseConstraints(result *[]*api.Constraint, list *ast.ObjectList) error {
 		// Check for invalid keys
 		valid := []string{
 			"attribute",
+			"distinct_hosts",
+			"distinct_property",
 			"operator",
-			"value",
-			"version",
 			"regexp",
-			"distinct_hosts",
 			"set_contains",
+			"value",
+			"version",
 		}
 		if err := checkHCLKeys(o.Val, valid); err != nil {
 			return err
@@ -467,6 +468,11 @@ func parseConstraints(result *[]*api.Constraint, list *ast.ObjectList) error {
 			m["Operand"] = structs.ConstraintDistinctHosts
 		}
 
+		if property, ok := m[structs.ConstraintDistinctProperty]; ok {
+			m["Operand"] = structs.ConstraintDistinctProperty
+			m["LTarget"] = property
+		}
+
 		// Build the constraint
 		var c api.Constraint
 		if err := mapstructure.WeakDecode(m, &c); err != nil {

jobspec/parse_test.go

@@ -303,6 +303,21 @@ func TestParse(t *testing.T) {
 			false,
 		},
 
+		{
+			"distinctProperty-constraint.hcl",
+			&api.Job{
+				ID:   helper.StringToPtr("foo"),
+				Name: helper.StringToPtr("foo"),
+				Constraints: []*api.Constraint{
+					&api.Constraint{
+						Operand: structs.ConstraintDistinctProperty,
+						LTarget: "${meta.rack}",
+					},
+				},
+			},
+			false,
+		},
+
 		{
 			"periodic-cron.hcl",
 			&api.Job{

jobspec/test-fixtures/distinctProperty-constraint.hcl

@@ -0,0 +1,5 @@
+job "foo" {
+    constraint {
+        distinct_property = "${meta.rack}"
+    }
+}

nomad/structs/structs.go

@@ -3189,10 +3189,11 @@ func (ta *TaskArtifact) Validate() error {
 }
 
 const (
-	ConstraintDistinctHosts = "distinct_hosts"
-	ConstraintRegex         = "regexp"
-	ConstraintVersion       = "version"
-	ConstraintSetContains   = "set_contains"
+	ConstraintDistinctProperty = "distinct_property"
+	ConstraintDistinctHosts    = "distinct_hosts"
+	ConstraintRegex            = "regexp"
+	ConstraintVersion          = "version"
+	ConstraintSetContains      = "set_contains"
 )
 
 // Constraints are used to restrict placement options.