template: validate only/except

template/template.go

@@ -91,6 +91,15 @@ func (t *Template) Validate() error {
 
 	// Verify that the provisioner overrides target builders that exist
 	for i, p := range t.Provisioners {
+		// Validate only/except
+		if verr := p.OnlyExcept.Validate(t); verr != nil {
+			for _, e := range multierror.Append(verr).Errors {
+				err = multierror.Append(err, fmt.Errorf(
+					"provisioner %d: %s", i+1, e))
+			}
+		}
+
+		// Validate overrides
 		for name, _ := range p.Override {
 			if _, ok := t.Builders[name]; !ok {
 				err = multierror.Append(err, fmt.Errorf(
@@ -103,6 +112,29 @@ func (t *Template) Validate() error {
 	return err
 }
 
+// Validate validates that the OnlyExcept settings are correct for a thing.
+func (o *OnlyExcept) Validate(t *Template) error {
+	if len(o.Only) > 0 && len(o.Except) > 0 {
+		return errors.New("only one of 'only' or 'except' may be specified")
+	}
+
+	var err error
+	for _, n := range o.Only {
+		if _, ok := t.Builders[n]; !ok {
+			err = multierror.Append(err, fmt.Errorf(
+				"'only' specified builder '%s' not found", n))
+		}
+	}
+	for _, n := range o.Except {
+		if _, ok := t.Builders[n]; !ok {
+			err = multierror.Append(err, fmt.Errorf(
+				"'except' specified builder '%s' not found", n))
+		}
+	}
+
+	return err
+}
+
 //-------------------------------------------------------------------
 // GoStringer
 //-------------------------------------------------------------------

template/template_test.go

@@ -32,6 +32,26 @@ func TestTemplateValidate(t *testing.T) {
 			"validate-good-override.json",
 			false,
 		},
+
+		{
+			"validate-bad-prov-only.json",
+			true,
+		},
+
+		{
+			"validate-good-prov-only.json",
+			false,
+		},
+
+		{
+			"validate-bad-prov-except.json",
+			true,
+		},
+
+		{
+			"validate-good-prov-except.json",
+			false,
+		},
 	}
 
 	for _, tc := range cases {

template/test-fixtures/validate-bad-prov-except.json

+{
+    "builders": [{
+        "type": "foo"
+    }],
+
+    "provisioners": [{
+        "type": "bar",
+        "except": ["bar"]
+    }]
+}

template/test-fixtures/validate-bad-prov-only.json

+{
+    "builders": [{
+        "type": "foo"
+    }],
+
+    "provisioners": [{
+        "type": "bar",
+        "only": ["bar"]
+    }]
+}

template/test-fixtures/validate-good-prov-except.json

+{
+    "builders": [{
+        "type": "foo"
+    }],
+
+    "provisioners": [{
+        "type": "bar",
+        "except": ["foo"]
+    }]
+}

template/test-fixtures/validate-good-prov-only.json

+{
+    "builders": [{
+        "type": "foo"
+    }],
+
+    "provisioners": [{
+        "type": "bar",
+        "only": ["foo"]
+    }]
+}