api: Implement bucket notification. (#2271)

* Implement basic S3 notifications through queues

Supports multiple queues and three basic queue types:

1. NilQueue -- messages don't get sent anywhere
2. LogQueue -- messages get logged
3. AmqpQueue -- messages are sent to an AMQP queue

* api: Implement bucket notification.

Supports two different queue types

- AMQP
- ElasticSearch.

* Add support for redis

vendor/gopkg.in/olivere/elastic.v3/fetch_source_context.go

@@ -0,0 +1,74 @@
+// Copyright 2012-2015 Oliver Eilhard. All rights reserved.
+// Use of this source code is governed by a MIT-license.
+// See http://olivere.mit-license.org/license.txt for details.
+
+package elastic
+
+import (
+	"net/url"
+	"strings"
+)
+
+type FetchSourceContext struct {
+	fetchSource     bool
+	transformSource bool
+	includes        []string
+	excludes        []string
+}
+
+func NewFetchSourceContext(fetchSource bool) *FetchSourceContext {
+	return &FetchSourceContext{
+		fetchSource: fetchSource,
+		includes:    make([]string, 0),
+		excludes:    make([]string, 0),
+	}
+}
+
+func (fsc *FetchSourceContext) FetchSource() bool {
+	return fsc.fetchSource
+}
+
+func (fsc *FetchSourceContext) SetFetchSource(fetchSource bool) {
+	fsc.fetchSource = fetchSource
+}
+
+func (fsc *FetchSourceContext) Include(includes ...string) *FetchSourceContext {
+	fsc.includes = append(fsc.includes, includes...)
+	return fsc
+}
+
+func (fsc *FetchSourceContext) Exclude(excludes ...string) *FetchSourceContext {
+	fsc.excludes = append(fsc.excludes, excludes...)
+	return fsc
+}
+
+func (fsc *FetchSourceContext) TransformSource(transformSource bool) *FetchSourceContext {
+	fsc.transformSource = transformSource
+	return fsc
+}
+
+func (fsc *FetchSourceContext) Source() (interface{}, error) {
+	if !fsc.fetchSource {
+		return false, nil
+	}
+	return map[string]interface{}{
+		"includes": fsc.includes,
+		"excludes": fsc.excludes,
+	}, nil
+}
+
+// Query returns the parameters in a form suitable for a URL query string.
+func (fsc *FetchSourceContext) Query() url.Values {
+	params := url.Values{}
+	if !fsc.fetchSource {
+		params.Add("_source", "false")
+		return params
+	}
+	if len(fsc.includes) > 0 {
+		params.Add("_source_include", strings.Join(fsc.includes, ","))
+	}
+	if len(fsc.excludes) > 0 {
+		params.Add("_source_exclude", strings.Join(fsc.excludes, ","))
+	}
+	return params
+}