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/clear_scroll.go

@@ -0,0 +1,162 @@
+// Copyright 2012-present 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"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// ClearScrollService clears one or more scroll contexts by their ids.
+//
+// See https://www.elastic.co/guide/en/elasticsearch/reference/7.0/search-request-scroll.html#_clear_scroll_api
+// for details.
+type ClearScrollService 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
+
+	scrollId []string
+}
+
+// NewClearScrollService creates a new ClearScrollService.
+func NewClearScrollService(client *Client) *ClearScrollService {
+	return &ClearScrollService{
+		client:   client,
+		scrollId: make([]string, 0),
+	}
+}
+
+// Pretty tells Elasticsearch whether to return a formatted JSON response.
+func (s *ClearScrollService) Pretty(pretty bool) *ClearScrollService {
+	s.pretty = &pretty
+	return s
+}
+
+// Human specifies whether human readable values should be returned in
+// the JSON response, e.g. "7.5mb".
+func (s *ClearScrollService) Human(human bool) *ClearScrollService {
+	s.human = &human
+	return s
+}
+
+// ErrorTrace specifies whether to include the stack trace of returned errors.
+func (s *ClearScrollService) ErrorTrace(errorTrace bool) *ClearScrollService {
+	s.errorTrace = &errorTrace
+	return s
+}
+
+// FilterPath specifies a list of filters used to reduce the response.
+func (s *ClearScrollService) FilterPath(filterPath ...string) *ClearScrollService {
+	s.filterPath = filterPath
+	return s
+}
+
+// Header adds a header to the request.
+func (s *ClearScrollService) Header(name string, value string) *ClearScrollService {
+	if s.headers == nil {
+		s.headers = http.Header{}
+	}
+	s.headers.Add(name, value)
+	return s
+}
+
+// Headers specifies the headers of the request.
+func (s *ClearScrollService) Headers(headers http.Header) *ClearScrollService {
+	s.headers = headers
+	return s
+}
+
+// ScrollId is a list of scroll IDs to clear.
+// Use _all to clear all search contexts.
+func (s *ClearScrollService) ScrollId(scrollIds ...string) *ClearScrollService {
+	s.scrollId = append(s.scrollId, scrollIds...)
+	return s
+}
+
+// buildURL builds the URL for the operation.
+func (s *ClearScrollService) buildURL() (string, url.Values, error) {
+	// Build URL
+	path := "/_search/scroll/"
+
+	// 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, ","))
+	}
+	return path, params, nil
+}
+
+// Validate checks if the operation is valid.
+func (s *ClearScrollService) Validate() error {
+	var invalid []string
+	if len(s.scrollId) == 0 {
+		invalid = append(invalid, "ScrollId")
+	}
+	if len(invalid) > 0 {
+		return fmt.Errorf("missing required fields: %v", invalid)
+	}
+	return nil
+}
+
+// Do executes the operation.
+func (s *ClearScrollService) Do(ctx context.Context) (*ClearScrollResponse, 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
+	}
+
+	// Setup HTTP request body
+	body := map[string][]string{
+		"scroll_id": s.scrollId,
+	}
+
+	// Get HTTP response
+	res, err := s.client.PerformRequest(ctx, PerformRequestOptions{
+		Method:  "DELETE",
+		Path:    path,
+		Params:  params,
+		Body:    body,
+		Headers: s.headers,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	// Return operation response
+	ret := new(ClearScrollResponse)
+	if err := s.client.decoder.Decode(res.Body, ret); err != nil {
+		return nil, err
+	}
+	return ret, nil
+}
+
+// ClearScrollResponse is the response of ClearScrollService.Do.
+type ClearScrollResponse struct {
+	Succeeded bool `json:"succeeded,omitempty"`
+	NumFreed  int  `json:"num_freed,omitempty"`
+}