Add basic authentication (#1683)

* Add basic authentication

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

vendor/github.com/prometheus/common/config/config.go

@@ -0,0 +1,34 @@
+// Copyright 2016 The Prometheus 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.
+
+// This package no longer handles safe yaml parsing. In order to
+// ensure correct yaml unmarshalling, use "yaml.UnmarshalStrict()".
+
+package config
+
+// Secret special type for storing secrets.
+type Secret string
+
+// MarshalYAML implements the yaml.Marshaler interface for Secrets.
+func (s Secret) MarshalYAML() (interface{}, error) {
+	if s != "" {
+		return "<secret>", nil
+	}
+	return nil, nil
+}
+
+//UnmarshalYAML implements the yaml.Unmarshaler interface for Secrets.
+func (s *Secret) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	type plain Secret
+	return unmarshal((*plain)(s))
+}