Refactoring external to leverage naming

pkg/naming/errors.go

@@ -0,0 +1,34 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package naming
+
+import "errors"
+
+var (
+	// ErrUnsupportedOperator creates an error that represents the fact that we were requested to service a query that
+	// Prometheus would be unable to support.
+	ErrUnsupportedOperator = errors.New("operator not supported by prometheus")
+
+	// ErrMalformedQuery creates an error that represents the fact that we were requested to service a query
+	// that was malformed in its operator/value combination.
+	ErrMalformedQuery = errors.New("operator requires values")
+
+	// ErrQueryUnsupportedValues creates an error that represents an unsupported return value from the
+	// specified query.
+	ErrQueryUnsupportedValues = errors.New("operator does not support values")
+
+	// ErrLabelNotSpecified creates an error that represents the fact that we were requested to service a query
+	// that was malformed in its label specification.
+	ErrLabelNotSpecified = errors.New("label not specified")
+)