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/get_template.go

@@ -0,0 +1,112 @@
+// 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 (
+	"fmt"
+	"net/url"
+
+	"gopkg.in/olivere/elastic.v3/uritemplates"
+)
+
+// GetTemplateService reads a search template.
+// It is documented at http://www.elasticsearch.org/guide/en/elasticsearch/reference/master/search-template.html.
+type GetTemplateService struct {
+	client      *Client
+	pretty      bool
+	id          string
+	version     interface{}
+	versionType string
+}
+
+// NewGetTemplateService creates a new GetTemplateService.
+func NewGetTemplateService(client *Client) *GetTemplateService {
+	return &GetTemplateService{
+		client: client,
+	}
+}
+
+// Id is the template ID.
+func (s *GetTemplateService) Id(id string) *GetTemplateService {
+	s.id = id
+	return s
+}
+
+// Version is an explicit version number for concurrency control.
+func (s *GetTemplateService) Version(version interface{}) *GetTemplateService {
+	s.version = version
+	return s
+}
+
+// VersionType is a specific version type.
+func (s *GetTemplateService) VersionType(versionType string) *GetTemplateService {
+	s.versionType = versionType
+	return s
+}
+
+// buildURL builds the URL for the operation.
+func (s *GetTemplateService) buildURL() (string, url.Values, error) {
+	// Build URL
+	path, err := uritemplates.Expand("/_search/template/{id}", map[string]string{
+		"id": s.id,
+	})
+	if err != nil {
+		return "", url.Values{}, err
+	}
+
+	// Add query string parameters
+	params := url.Values{}
+	if s.version != nil {
+		params.Set("version", fmt.Sprintf("%v", s.version))
+	}
+	if s.versionType != "" {
+		params.Set("version_type", s.versionType)
+	}
+
+	return path, params, nil
+}
+
+// Validate checks if the operation is valid.
+func (s *GetTemplateService) Validate() error {
+	var invalid []string
+	if s.id == "" {
+		invalid = append(invalid, "Id")
+	}
+	if len(invalid) > 0 {
+		return fmt.Errorf("missing required fields: %v", invalid)
+	}
+	return nil
+}
+
+// Do executes the operation and returns the template.
+func (s *GetTemplateService) Do() (*GetTemplateResponse, error) {
+	// Check pre-conditions
+	if err := s.Validate(); err != nil {
+		return nil, err
+	}
+
+	// Get URL for request
+	path, params, err := s.buildURL()
+	if err != nil {
+		return nil, err
+	}
+
+	// Get HTTP response
+	res, err := s.client.PerformRequest("GET", path, params, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Return result
+	ret := new(GetTemplateResponse)
+	if err := s.client.decoder.Decode(res.Body, ret); err != nil {
+		return nil, err
+	}
+	return ret, nil
+}
+
+type GetTemplateResponse struct {
+	Template string `json:"template"`
+}