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/field_caps.go

@@ -0,0 +1,257 @@
+// 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"
+
+	"github.com/olivere/elastic/v7/uritemplates"
+)
+
+// FieldCapsService allows retrieving the capabilities of fields among multiple indices.
+//
+// See https://www.elastic.co/guide/en/elasticsearch/reference/7.0/search-field-caps.html
+// for details
+type FieldCapsService 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
+
+	index             []string
+	allowNoIndices    *bool
+	expandWildcards   string
+	fields            []string
+	ignoreUnavailable *bool
+	bodyJson          interface{}
+	bodyString        string
+}
+
+// NewFieldCapsService creates a new FieldCapsService
+func NewFieldCapsService(client *Client) *FieldCapsService {
+	return &FieldCapsService{
+		client: client,
+	}
+}
+
+// Pretty tells Elasticsearch whether to return a formatted JSON response.
+func (s *FieldCapsService) Pretty(pretty bool) *FieldCapsService {
+	s.pretty = &pretty
+	return s
+}
+
+// Human specifies whether human readable values should be returned in
+// the JSON response, e.g. "7.5mb".
+func (s *FieldCapsService) Human(human bool) *FieldCapsService {
+	s.human = &human
+	return s
+}
+
+// ErrorTrace specifies whether to include the stack trace of returned errors.
+func (s *FieldCapsService) ErrorTrace(errorTrace bool) *FieldCapsService {
+	s.errorTrace = &errorTrace
+	return s
+}
+
+// FilterPath specifies a list of filters used to reduce the response.
+func (s *FieldCapsService) FilterPath(filterPath ...string) *FieldCapsService {
+	s.filterPath = filterPath
+	return s
+}
+
+// Header adds a header to the request.
+func (s *FieldCapsService) Header(name string, value string) *FieldCapsService {
+	if s.headers == nil {
+		s.headers = http.Header{}
+	}
+	s.headers.Add(name, value)
+	return s
+}
+
+// Headers specifies the headers of the request.
+func (s *FieldCapsService) Headers(headers http.Header) *FieldCapsService {
+	s.headers = headers
+	return s
+}
+
+// Index is a list of index names; use `_all` or empty string to perform
+// the operation on all indices.
+func (s *FieldCapsService) Index(index ...string) *FieldCapsService {
+	s.index = append(s.index, index...)
+	return s
+}
+
+// AllowNoIndices indicates whether to ignore if a wildcard indices expression
+// resolves into no concrete indices.
+// (This includes `_all` string or when no indices have been specified).
+func (s *FieldCapsService) AllowNoIndices(allowNoIndices bool) *FieldCapsService {
+	s.allowNoIndices = &allowNoIndices
+	return s
+}
+
+// ExpandWildcards indicates whether to expand wildcard expression to
+// concrete indices that are open, closed or both.
+func (s *FieldCapsService) ExpandWildcards(expandWildcards string) *FieldCapsService {
+	s.expandWildcards = expandWildcards
+	return s
+}
+
+// Fields is a list of fields for to get field capabilities.
+func (s *FieldCapsService) Fields(fields ...string) *FieldCapsService {
+	s.fields = append(s.fields, fields...)
+	return s
+}
+
+// IgnoreUnavailable is documented as: Whether specified concrete indices should be ignored when unavailable (missing or closed).
+func (s *FieldCapsService) IgnoreUnavailable(ignoreUnavailable bool) *FieldCapsService {
+	s.ignoreUnavailable = &ignoreUnavailable
+	return s
+}
+
+// BodyJson is documented as: Field json objects containing the name and optionally a range to filter out indices result, that have results outside the defined bounds.
+func (s *FieldCapsService) BodyJson(body interface{}) *FieldCapsService {
+	s.bodyJson = body
+	return s
+}
+
+// BodyString is documented as: Field json objects containing the name and optionally a range to filter out indices result, that have results outside the defined bounds.
+func (s *FieldCapsService) BodyString(body string) *FieldCapsService {
+	s.bodyString = body
+	return s
+}
+
+// buildURL builds the URL for the operation.
+func (s *FieldCapsService) buildURL() (string, url.Values, error) {
+	// Build URL
+	var err error
+	var path string
+	if len(s.index) > 0 {
+		path, err = uritemplates.Expand("/{index}/_field_caps", map[string]string{
+			"index": strings.Join(s.index, ","),
+		})
+	} else {
+		path = "/_field_caps"
+	}
+	if err != nil {
+		return "", url.Values{}, err
+	}
+
+	// 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 s.allowNoIndices != nil {
+		params.Set("allow_no_indices", fmt.Sprintf("%v", *s.allowNoIndices))
+	}
+	if s.expandWildcards != "" {
+		params.Set("expand_wildcards", s.expandWildcards)
+	}
+	if len(s.fields) > 0 {
+		params.Set("fields", strings.Join(s.fields, ","))
+	}
+	if s.ignoreUnavailable != nil {
+		params.Set("ignore_unavailable", fmt.Sprintf("%v", *s.ignoreUnavailable))
+	}
+	return path, params, nil
+}
+
+// Validate checks if the operation is valid.
+func (s *FieldCapsService) Validate() error {
+	return nil
+}
+
+// Do executes the operation.
+func (s *FieldCapsService) Do(ctx context.Context) (*FieldCapsResponse, 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
+	var body interface{}
+	if s.bodyJson != nil {
+		body = s.bodyJson
+	} else {
+		body = s.bodyString
+	}
+
+	// Get HTTP response
+	res, err := s.client.PerformRequest(ctx, PerformRequestOptions{
+		Method:       "POST",
+		Path:         path,
+		Params:       params,
+		Body:         body,
+		IgnoreErrors: []int{http.StatusNotFound},
+		Headers:      s.headers,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO(oe): Is 404 really a valid response here?
+	if res.StatusCode == http.StatusNotFound {
+		return &FieldCapsResponse{}, nil
+	}
+
+	// Return operation response
+	ret := new(FieldCapsResponse)
+	if err := s.client.decoder.Decode(res.Body, ret); err != nil {
+		return nil, err
+	}
+	return ret, nil
+}
+
+// -- Request --
+
+// FieldCapsRequest can be used to set up the body to be used in the
+// Field Capabilities API.
+type FieldCapsRequest struct {
+	Fields []string `json:"fields"`
+}
+
+// -- Response --
+
+// FieldCapsResponse contains field capabilities.
+type FieldCapsResponse struct {
+	Indices []string                 `json:"indices,omitempty"` // list of index names
+	Fields  map[string]FieldCapsType `json:"fields,omitempty"`  // Name -> type -> caps
+}
+
+// FieldCapsType represents a mapping from type (e.g. keyword)
+// to capabilities.
+type FieldCapsType map[string]FieldCaps // type -> caps
+
+// FieldCaps contains capabilities of an individual field.
+type FieldCaps struct {
+	Type                   string   `json:"type"`
+	Searchable             bool     `json:"searchable"`
+	Aggregatable           bool     `json:"aggregatable"`
+	Indices                []string `json:"indices,omitempty"`
+	NonSearchableIndices   []string `json:"non_searchable_indices,omitempty"`
+	NonAggregatableIndices []string `json:"non_aggregatable_indices,omitempty"`
+}