Issue search support elasticsearch (#9428)

* Issue search support elasticsearch

* Fix lint

* Add indexer name on app.ini

* add a warnning on SearchIssuesByKeyword

* improve code

vendor/github.com/olivere/elastic/v7/xpack_watcher_stats.go

@@ -0,0 +1,165 @@
+// Copyright 2012-2018 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 (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// XPackWatcherStatsService returns the current watcher metrics.
+// See https://www.elastic.co/guide/en/elasticsearch/reference/7.0/watcher-api-stats.html.
+type XPackWatcherStatsService struct {
+	client *Client
+
+	pretty     *bool       // pretty format the returned JSON response
+	human      *bool       // return human readable values for statistics
+	errorTrace *bool       // include the stack trace of returned errors
+	filterPath []string    // list of filters used to reduce the response
+	headers    http.Header // custom request-level HTTP headers
+
+	metric          string
+	emitStacktraces *bool
+}
+
+// NewXPackWatcherStatsService creates a new XPackWatcherStatsService.
+func NewXPackWatcherStatsService(client *Client) *XPackWatcherStatsService {
+	return &XPackWatcherStatsService{
+		client: client,
+	}
+}
+
+// Pretty tells Elasticsearch whether to return a formatted JSON response.
+func (s *XPackWatcherStatsService) Pretty(pretty bool) *XPackWatcherStatsService {
+	s.pretty = &pretty
+	return s
+}
+
+// Human specifies whether human readable values should be returned in
+// the JSON response, e.g. "7.5mb".
+func (s *XPackWatcherStatsService) Human(human bool) *XPackWatcherStatsService {
+	s.human = &human
+	return s
+}
+
+// ErrorTrace specifies whether to include the stack trace of returned errors.
+func (s *XPackWatcherStatsService) ErrorTrace(errorTrace bool) *XPackWatcherStatsService {
+	s.errorTrace = &errorTrace
+	return s
+}
+
+// FilterPath specifies a list of filters used to reduce the response.
+func (s *XPackWatcherStatsService) FilterPath(filterPath ...string) *XPackWatcherStatsService {
+	s.filterPath = filterPath
+	return s
+}
+
+// Header adds a header to the request.
+func (s *XPackWatcherStatsService) Header(name string, value string) *XPackWatcherStatsService {
+	if s.headers == nil {
+		s.headers = http.Header{}
+	}
+	s.headers.Add(name, value)
+	return s
+}
+
+// Headers specifies the headers of the request.
+func (s *XPackWatcherStatsService) Headers(headers http.Header) *XPackWatcherStatsService {
+	s.headers = headers
+	return s
+}
+
+// Metric controls what additional stat metrics should be include in the response.
+func (s *XPackWatcherStatsService) Metric(metric string) *XPackWatcherStatsService {
+	s.metric = metric
+	return s
+}
+
+// EmitStacktraces, if enabled, emits stack traces of currently running watches.
+func (s *XPackWatcherStatsService) EmitStacktraces(emitStacktraces bool) *XPackWatcherStatsService {
+	s.emitStacktraces = &emitStacktraces
+	return s
+}
+
+// buildURL builds the URL for the operation.
+func (s *XPackWatcherStatsService) buildURL() (string, url.Values, error) {
+	// Build URL
+	path := "/_watcher/stats"
+
+	// Add query string parameters
+	params := url.Values{}
+	if v := s.pretty; v != nil {
+		params.Set("pretty", fmt.Sprint(*v))
+	}
+	if v := s.human; v != nil {
+		params.Set("human", fmt.Sprint(*v))
+	}
+	if v := s.errorTrace; v != nil {
+		params.Set("error_trace", fmt.Sprint(*v))
+	}
+	if len(s.filterPath) > 0 {
+		params.Set("filter_path", strings.Join(s.filterPath, ","))
+	}
+	if v := s.emitStacktraces; v != nil {
+		params.Set("emit_stacktraces", fmt.Sprint(*v))
+	}
+	if s.metric != "" {
+		params.Set("metric", s.metric)
+	}
+	return path, params, nil
+}
+
+// Validate checks if the operation is valid.
+func (s *XPackWatcherStatsService) Validate() error {
+	return nil
+}
+
+// Do executes the operation.
+func (s *XPackWatcherStatsService) Do(ctx context.Context) (*XPackWatcherStatsResponse, 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(ctx, PerformRequestOptions{
+		Method:  "GET",
+		Path:    path,
+		Params:  params,
+		Headers: s.headers,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	// Return operation response
+	ret := new(XPackWatcherStatsResponse)
+	if err := json.Unmarshal(res.Body, ret); err != nil {
+		return nil, err
+	}
+	return ret, nil
+}
+
+// XPackWatcherStatsResponse is the response of XPackWatcherStatsService.Do.
+type XPackWatcherStatsResponse struct {
+	Stats []XPackWatcherStats `json:"stats"`
+}
+
+// XPackWatcherStats represents the stats used in XPackWatcherStatsResponse.
+type XPackWatcherStats struct {
+	WatcherState        string                 `json:"watcher_state"`
+	WatchCount          int                    `json:"watch_count"`
+	ExecutionThreadPool map[string]interface{} `json:"execution_thread_pool"`
+}