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/errors.go

@@ -0,0 +1,141 @@
+// 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 (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+)
+
+// checkResponse will return an error if the request/response indicates
+// an error returned from Elasticsearch.
+//
+// HTTP status codes between in the range [200..299] are considered successful.
+// All other errors are considered errors except they are specified in
+// ignoreErrors. This is necessary because for some services, HTTP status 404
+// is a valid response from Elasticsearch (e.g. the Exists service).
+//
+// The func tries to parse error details as returned from Elasticsearch
+// and encapsulates them in type elastic.Error.
+func checkResponse(req *http.Request, res *http.Response, ignoreErrors ...int) error {
+	// 200-299 are valid status codes
+	if res.StatusCode >= 200 && res.StatusCode <= 299 {
+		return nil
+	}
+	// Ignore certain errors?
+	for _, code := range ignoreErrors {
+		if code == res.StatusCode {
+			return nil
+		}
+	}
+	return createResponseError(res)
+}
+
+// createResponseError creates an Error structure from the HTTP response,
+// its status code and the error information sent by Elasticsearch.
+func createResponseError(res *http.Response) error {
+	if res.Body == nil {
+		return &Error{Status: res.StatusCode}
+	}
+	data, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return &Error{Status: res.StatusCode}
+	}
+	errReply := new(Error)
+	err = json.Unmarshal(data, errReply)
+	if err != nil {
+		return &Error{Status: res.StatusCode}
+	}
+	if errReply != nil {
+		if errReply.Status == 0 {
+			errReply.Status = res.StatusCode
+		}
+		return errReply
+	}
+	return &Error{Status: res.StatusCode}
+}
+
+// Error encapsulates error details as returned from Elasticsearch.
+type Error struct {
+	Status  int           `json:"status"`
+	Details *ErrorDetails `json:"error,omitempty"`
+}
+
+// ErrorDetails encapsulate error details from Elasticsearch.
+// It is used in e.g. elastic.Error and elastic.BulkResponseItem.
+type ErrorDetails struct {
+	Type         string                   `json:"type"`
+	Reason       string                   `json:"reason"`
+	ResourceType string                   `json:"resource.type,omitempty"`
+	ResourceId   string                   `json:"resource.id,omitempty"`
+	Index        string                   `json:"index,omitempty"`
+	Phase        string                   `json:"phase,omitempty"`
+	Grouped      bool                     `json:"grouped,omitempty"`
+	CausedBy     map[string]interface{}   `json:"caused_by,omitempty"`
+	RootCause    []*ErrorDetails          `json:"root_cause,omitempty"`
+	FailedShards []map[string]interface{} `json:"failed_shards,omitempty"`
+}
+
+// Error returns a string representation of the error.
+func (e *Error) Error() string {
+	if e.Details != nil && e.Details.Reason != "" {
+		return fmt.Sprintf("elastic: Error %d (%s): %s [type=%s]", e.Status, http.StatusText(e.Status), e.Details.Reason, e.Details.Type)
+	} else {
+		return fmt.Sprintf("elastic: Error %d (%s)", e.Status, http.StatusText(e.Status))
+	}
+}
+
+// IsNotFound returns true if the given error indicates that Elasticsearch
+// returned HTTP status 404. The err parameter can be of type *elastic.Error,
+// elastic.Error, *http.Response or int (indicating the HTTP status code).
+func IsNotFound(err interface{}) bool {
+	switch e := err.(type) {
+	case *http.Response:
+		return e.StatusCode == http.StatusNotFound
+	case *Error:
+		return e.Status == http.StatusNotFound
+	case Error:
+		return e.Status == http.StatusNotFound
+	case int:
+		return e == http.StatusNotFound
+	}
+	return false
+}
+
+// IsTimeout returns true if the given error indicates that Elasticsearch
+// returned HTTP status 408. The err parameter can be of type *elastic.Error,
+// elastic.Error, *http.Response or int (indicating the HTTP status code).
+func IsTimeout(err interface{}) bool {
+	switch e := err.(type) {
+	case *http.Response:
+		return e.StatusCode == http.StatusRequestTimeout
+	case *Error:
+		return e.Status == http.StatusRequestTimeout
+	case Error:
+		return e.Status == http.StatusRequestTimeout
+	case int:
+		return e == http.StatusRequestTimeout
+	}
+	return false
+}
+
+// -- General errors --
+
+// shardsInfo represents information from a shard.
+type shardsInfo struct {
+	Total      int `json:"total"`
+	Successful int `json:"successful"`
+	Failed     int `json:"failed"`
+}
+
+// shardOperationFailure represents a shard failure.
+type shardOperationFailure struct {
+	Shard  int    `json:"shard"`
+	Index  string `json:"index"`
+	Status string `json:"status"`
+	// "reason"
+}