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/script.go

@@ -0,0 +1,131 @@
+// 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 "errors"
+
+// Script holds all the paramaters necessary to compile or find in cache
+// and then execute a script.
+//
+// See https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-scripting.html
+// for details of scripting.
+type Script struct {
+	script string
+	typ    string
+	lang   string
+	params map[string]interface{}
+}
+
+// NewScript creates and initializes a new Script.
+func NewScript(script string) *Script {
+	return &Script{
+		script: script,
+		typ:    "", // default type is "inline"
+		params: make(map[string]interface{}),
+	}
+}
+
+// NewScriptInline creates and initializes a new Script of type "inline".
+func NewScriptInline(script string) *Script {
+	return NewScript(script).Type("inline")
+}
+
+// NewScriptId creates and initializes a new Script of type "id".
+func NewScriptId(script string) *Script {
+	return NewScript(script).Type("id")
+}
+
+// NewScriptFile creates and initializes a new Script of type "file".
+func NewScriptFile(script string) *Script {
+	return NewScript(script).Type("file")
+}
+
+// Script is either the cache key of the script to be compiled/executed
+// or the actual script source code for inline scripts. For indexed
+// scripts this is the id used in the request. For file scripts this is
+// the file name.
+func (s *Script) Script(script string) *Script {
+	s.script = script
+	return s
+}
+
+// Type sets the type of script: "inline", "id", or "file".
+func (s *Script) Type(typ string) *Script {
+	s.typ = typ
+	return s
+}
+
+// Lang sets the language of the script. Permitted values are "groovy",
+// "expression", "mustache", "mvel" (default), "javascript", "python".
+// To use certain languages, you need to configure your server and/or
+// add plugins. See https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-scripting.html
+// for details.
+func (s *Script) Lang(lang string) *Script {
+	s.lang = lang
+	return s
+}
+
+// Param adds a key/value pair to the parameters that this script will be executed with.
+func (s *Script) Param(name string, value interface{}) *Script {
+	if s.params == nil {
+		s.params = make(map[string]interface{})
+	}
+	s.params[name] = value
+	return s
+}
+
+// Params sets the map of parameters this script will be executed with.
+func (s *Script) Params(params map[string]interface{}) *Script {
+	s.params = params
+	return s
+}
+
+// Source returns the JSON serializable data for this Script.
+func (s *Script) Source() (interface{}, error) {
+	if s.typ == "" && s.lang == "" && len(s.params) == 0 {
+		return s.script, nil
+	}
+	source := make(map[string]interface{})
+	if s.typ == "" {
+		source["inline"] = s.script
+	} else {
+		source[s.typ] = s.script
+	}
+	if s.lang != "" {
+		source["lang"] = s.lang
+	}
+	if len(s.params) > 0 {
+		source["params"] = s.params
+	}
+	return source, nil
+}
+
+// -- Script Field --
+
+// ScriptField is a single script field.
+type ScriptField struct {
+	FieldName string // name of the field
+
+	script *Script
+}
+
+// NewScriptField creates and initializes a new ScriptField.
+func NewScriptField(fieldName string, script *Script) *ScriptField {
+	return &ScriptField{FieldName: fieldName, script: script}
+}
+
+// Source returns the serializable JSON for the ScriptField.
+func (f *ScriptField) Source() (interface{}, error) {
+	if f.script == nil {
+		return nil, errors.New("ScriptField expects script")
+	}
+	source := make(map[string]interface{})
+	src, err := f.script.Source()
+	if err != nil {
+		return nil, err
+	}
+	source["script"] = src
+	return source, nil
+}