goes/goes.go
2017-03-02 18:58:52 -06:00

658 lines
16 KiB
Go

// Copyright 2013 Belogik. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package goes provides an API to access Elasticsearch.
package goes
import (
"bytes"
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"net/http"
"net/url"
"reflect"
"strconv"
"strings"
)
const (
// BulkCommandIndex specifies a bulk doc should be indexed
BulkCommandIndex = "index"
// BulkCommandDelete specifies a bulk doc should be deleted
BulkCommandDelete = "delete"
)
func (err *SearchError) Error() string {
return fmt.Sprintf("[%d] %s", err.StatusCode, err.Msg)
}
// NewClient initiates a new client for an elasticsearch server
//
// This function is pretty useless for now but might be useful in a near future
// if wee need more features like connection pooling or load balancing.
func NewClient(host string, port string) *Client {
if !strings.HasPrefix(host, "http://") && !strings.HasPrefix(host, "https://") {
host = "http://" + host
}
host = host + ":" + port
u, err := url.Parse(host)
if err != nil {
panic(err)
}
return &Client{u, http.DefaultClient, ""}
}
// WithHTTPClient sets the http.Client to be used with the connection. Returns the original client.
func (c *Client) WithHTTPClient(cl *http.Client) *Client {
c.Client = cl
return c
}
// Version returns the detected version of the connected ES server
func (c *Client) Version() (string, error) {
// Use cached version if it was already fetched
if c.version != "" {
return c.version, nil
}
// Get the version if it was not cached
r := Request{Method: "GET"}
res, err := c.Do(&r)
if err != nil {
return "", err
}
if version, ok := res.Raw["version"].(map[string]interface{}); ok {
if number, ok := version["number"].(string); ok {
c.version = number
return number, nil
}
}
return "", errors.New("No version returned by ElasticSearch Server")
}
// CreateIndex creates a new index represented by a name and a mapping
func (c *Client) CreateIndex(name string, mapping interface{}) (*Response, error) {
r := Request{
Query: mapping,
IndexList: []string{name},
Method: "PUT",
}
return c.Do(&r)
}
// DeleteIndex deletes an index represented by a name
func (c *Client) DeleteIndex(name string) (*Response, error) {
r := Request{
IndexList: []string{name},
Method: "DELETE",
}
return c.Do(&r)
}
// RefreshIndex refreshes an index represented by a name
func (c *Client) RefreshIndex(name string) (*Response, error) {
r := Request{
IndexList: []string{name},
Method: "POST",
API: "_refresh",
}
return c.Do(&r)
}
// UpdateIndexSettings updates settings for existing index represented by a name and a settings
// as described here: https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-update-settings.html
func (c *Client) UpdateIndexSettings(name string, settings interface{}) (*Response, error) {
r := Request{
Query: settings,
IndexList: []string{name},
Method: "PUT",
API: "_settings",
}
return c.Do(&r)
}
// Optimize an index represented by a name, extra args are also allowed please check:
// http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/indices-optimize.html#indices-optimize
func (c *Client) Optimize(indexList []string, extraArgs url.Values) (*Response, error) {
r := Request{
IndexList: indexList,
ExtraArgs: extraArgs,
Method: "POST",
API: "_optimize",
}
if version, _ := c.Version(); version > "2.1" {
r.API = "_forcemerge"
}
return c.Do(&r)
}
// ForceMerge is the same as Optimize, but matches the naming of the endpoint as of ES 2.1.0
func (c *Client) ForceMerge(indexList []string, extraArgs url.Values) (*Response, error) {
return c.Optimize(indexList, extraArgs)
}
// Stats fetches statistics (_stats) for the current elasticsearch server
func (c *Client) Stats(indexList []string, extraArgs url.Values) (*Response, error) {
r := Request{
IndexList: indexList,
ExtraArgs: extraArgs,
Method: "GET",
API: "_stats",
}
return c.Do(&r)
}
// IndexStatus fetches the status (_status) for the indices defined in
// indexList. Use _all in indexList to get stats for all indices
func (c *Client) IndexStatus(indexList []string) (*Response, error) {
r := Request{
IndexList: indexList,
Method: "GET",
API: "_status",
}
return c.Do(&r)
}
// BulkSend bulk adds multiple documents in bulk mode
func (c *Client) BulkSend(documents []Document) (*Response, error) {
// We do not generate a traditional JSON here (often a one liner)
// Elasticsearch expects one line of JSON per line (EOL = \n)
// plus an extra \n at the very end of the document
//
// More informations about the Bulk JSON format for Elasticsearch:
//
// - http://www.elasticsearch.org/guide/reference/api/bulk.html
//
// This is quite annoying for us as we can not use the simple JSON
// Marshaler available in Run().
//
// We have to generate this special JSON by ourselves which leads to
// the code below.
//
// I know it is unreadable I must find an elegant way to fix this.
// len(documents) * 2 : action + optional_sources
// + 1 : room for the trailing \n
bulkData := make([][]byte, 0, len(documents)*2+1)
i := 0
for _, doc := range documents {
action, err := json.Marshal(map[string]interface{}{
doc.BulkCommand: map[string]interface{}{
"_index": doc.Index,
"_type": doc.Type,
"_id": doc.ID,
},
})
if err != nil {
return &Response{}, err
}
bulkData = append(bulkData, action)
i++
if doc.Fields != nil {
if docFields, ok := doc.Fields.(map[string]interface{}); ok {
if len(docFields) == 0 {
continue
}
} else {
typeOfFields := reflect.TypeOf(doc.Fields)
if typeOfFields.Kind() == reflect.Ptr {
typeOfFields = typeOfFields.Elem()
}
if typeOfFields.Kind() != reflect.Struct {
return &Response{}, fmt.Errorf("Document fields not in struct or map[string]interface{} format")
}
if typeOfFields.NumField() == 0 {
continue
}
}
sources, err := json.Marshal(doc.Fields)
if err != nil {
return &Response{}, err
}
bulkData = append(bulkData, sources)
i++
}
}
// forces an extra trailing \n absolutely necessary for elasticsearch
bulkData = append(bulkData, []byte(nil))
r := Request{
Method: "POST",
API: "_bulk",
BulkData: bytes.Join(bulkData, []byte("\n")),
}
resp, err := c.Do(&r)
if err != nil {
return resp, err
}
if resp.Errors {
for _, item := range resp.Items {
for _, i := range item {
if i.Error != "" {
return resp, &SearchError{i.Error, i.Status}
}
}
}
return resp, &SearchError{Msg: "Unknown error while bulk indexing"}
}
return resp, err
}
// Search executes a search query against an index
func (c *Client) Search(query interface{}, indexList []string, typeList []string, extraArgs url.Values) (*Response, error) {
r := Request{
Query: query,
IndexList: indexList,
TypeList: typeList,
Method: "POST",
API: "_search",
ExtraArgs: extraArgs,
}
return c.Do(&r)
}
// Count executes a count query against an index, use the Count field in the response for the result
func (c *Client) Count(query interface{}, indexList []string, typeList []string, extraArgs url.Values) (*Response, error) {
r := Request{
Query: query,
IndexList: indexList,
TypeList: typeList,
Method: "POST",
API: "_count",
ExtraArgs: extraArgs,
}
return c.Do(&r)
}
//Query runs a query against an index using the provided http method.
//This method can be used to execute a delete by query, just pass in "DELETE"
//for the HTTP method.
func (c *Client) Query(query interface{}, indexList []string, typeList []string, httpMethod string, extraArgs url.Values) (*Response, error) {
r := Request{
Query: query,
IndexList: indexList,
TypeList: typeList,
Method: httpMethod,
API: "_query",
ExtraArgs: extraArgs,
}
return c.Do(&r)
}
// DeleteByQuery deletes documents matching the specified query. It will return an error for ES 2.x,
// because delete by query support was removed in those versions.
func (c *Client) DeleteByQuery(query interface{}, indexList []string, typeList []string, extraArgs url.Values) (*Response, error) {
version, err := c.Version()
if err != nil {
return nil, err
}
if version > "2" && version < "5" {
return nil, errors.New("ElasticSearch 2.x does not support delete by query")
}
r := Request{
Query: query,
IndexList: indexList,
TypeList: typeList,
Method: "DELETE",
API: "_query",
ExtraArgs: extraArgs,
}
if version > "5" {
r.API = "_delete_by_query"
r.Method = "POST"
}
return c.Do(&r)
}
// Scan starts scroll over an index.
// For ES versions < 5.x, it uses search_type=scan; for 5.x it uses sort=_doc. This means that data
// will be returned in the initial response for 5.x versions, but not for older versions. Code
// wishing to be compatible with both should be written to handle either case.
func (c *Client) Scan(query interface{}, indexList []string, typeList []string, timeout string, size int) (*Response, error) {
v := url.Values{}
version, err := c.Version()
if err != nil {
return nil, err
}
if version > "5" {
v.Add("sort", "_doc")
} else {
v.Add("search_type", "scan")
}
v.Add("scroll", timeout)
v.Add("size", strconv.Itoa(size))
r := Request{
Query: query,
IndexList: indexList,
TypeList: typeList,
Method: "POST",
API: "_search",
ExtraArgs: v,
}
return c.Do(&r)
}
// Scroll fetches data by scroll id
func (c *Client) Scroll(scrollID string, timeout string) (*Response, error) {
r := Request{
Method: "POST",
API: "_search/scroll",
}
if version, err := c.Version(); err != nil {
return nil, err
} else if version > "2" {
r.Body, err = json.Marshal(map[string]string{"scroll": timeout, "scroll_id": scrollID})
if err != nil {
return nil, err
}
} else {
v := url.Values{}
v.Add("scroll", timeout)
v.Add("scroll_id", scrollID)
r.ExtraArgs = v
}
return c.Do(&r)
}
// Get a typed document by its id
func (c *Client) Get(index string, documentType string, id string, extraArgs url.Values) (*Response, error) {
r := Request{
IndexList: []string{index},
Method: "GET",
API: documentType + "/" + id,
ExtraArgs: extraArgs,
}
return c.Do(&r)
}
// Index indexes a Document
// The extraArgs is a list of url.Values that you can send to elasticsearch as
// URL arguments, for example, to control routing, ttl, version, op_type, etc.
func (c *Client) Index(d Document, extraArgs url.Values) (*Response, error) {
r := Request{
Query: d.Fields,
IndexList: []string{d.Index.(string)},
TypeList: []string{d.Type},
ExtraArgs: extraArgs,
Method: "POST",
}
if d.ID != nil {
r.Method = "PUT"
r.ID = d.ID.(string)
}
return c.Do(&r)
}
// Delete deletes a Document d
// The extraArgs is a list of url.Values that you can send to elasticsearch as
// URL arguments, for example, to control routing.
func (c *Client) Delete(d Document, extraArgs url.Values) (*Response, error) {
r := Request{
IndexList: []string{d.Index.(string)},
TypeList: []string{d.Type},
ExtraArgs: extraArgs,
Method: "DELETE",
ID: d.ID.(string),
}
return c.Do(&r)
}
// Buckets returns list of buckets in aggregation
func (a Aggregation) Buckets() []Bucket {
result := []Bucket{}
if buckets, ok := a["buckets"]; ok {
for _, bucket := range buckets.([]interface{}) {
result = append(result, bucket.(map[string]interface{}))
}
}
return result
}
// Key returns key for aggregation bucket
func (b Bucket) Key() interface{} {
return b["key"]
}
// DocCount returns count of documents in this bucket
func (b Bucket) DocCount() uint64 {
return uint64(b["doc_count"].(float64))
}
// Aggregation returns aggregation by name from bucket
func (b Bucket) Aggregation(name string) Aggregation {
if agg, ok := b[name]; ok {
return agg.(map[string]interface{})
}
return Aggregation{}
}
// PutMapping registers a specific mapping for one or more types in one or more indexes
func (c *Client) PutMapping(typeName string, mapping interface{}, indexes []string) (*Response, error) {
r := Request{
Query: mapping,
IndexList: indexes,
Method: "PUT",
API: "_mappings/" + typeName,
}
return c.Do(&r)
}
// GetMapping returns the mappings for the specified types
func (c *Client) GetMapping(types []string, indexes []string) (*Response, error) {
r := Request{
IndexList: indexes,
Method: "GET",
API: "_mapping/" + strings.Join(types, ","),
}
return c.Do(&r)
}
// IndicesExist checks whether index (or indices) exist on the server
func (c *Client) IndicesExist(indexes []string) (bool, error) {
r := Request{
IndexList: indexes,
Method: "HEAD",
}
resp, err := c.Do(&r)
return resp.Status == 200, err
}
// Update updates the specified document using the _update endpoint
func (c *Client) Update(d Document, query interface{}, extraArgs url.Values) (*Response, error) {
r := Request{
Query: query,
IndexList: []string{d.Index.(string)},
TypeList: []string{d.Type},
ExtraArgs: extraArgs,
Method: "POST",
API: "_update",
}
if d.ID != nil {
r.ID = d.ID.(string)
}
return c.Do(&r)
}
// DeleteMapping deletes a mapping along with all data in the type
func (c *Client) DeleteMapping(typeName string, indexes []string) (*Response, error) {
if version, err := c.Version(); err != nil {
return nil, err
} else if version > "2" {
return nil, errors.New("Deletion of mappings is not supported in ES 2.x and above.")
}
r := Request{
IndexList: indexes,
Method: "DELETE",
API: "_mappings/" + typeName,
}
return c.Do(&r)
}
func (c *Client) modifyAlias(action string, alias string, indexes []string) (*Response, error) {
command := map[string]interface{}{
"actions": make([]map[string]interface{}, 0, 1),
}
for _, index := range indexes {
command["actions"] = append(command["actions"].([]map[string]interface{}), map[string]interface{}{
action: map[string]interface{}{
"index": index,
"alias": alias,
},
})
}
r := Request{
Query: command,
Method: "POST",
API: "_aliases",
}
return c.Do(&r)
}
// AddAlias creates an alias to one or more indexes
func (c *Client) AddAlias(alias string, indexes []string) (*Response, error) {
return c.modifyAlias("add", alias, indexes)
}
// RemoveAlias removes an alias to one or more indexes
func (c *Client) RemoveAlias(alias string, indexes []string) (*Response, error) {
return c.modifyAlias("remove", alias, indexes)
}
// AliasExists checks whether alias is defined on the server
func (c *Client) AliasExists(alias string) (bool, error) {
r := Request{
Method: "HEAD",
API: "_alias/" + alias,
}
resp, err := c.Do(&r)
return resp.Status == 200, err
}
func (c *Client) replaceHost(req *http.Request) {
req.URL.Scheme = c.Host.Scheme
req.URL.Host = c.Host.Host
}
// DoRaw Does the provided requeset and returns the raw bytes and the status code of the response
func (c *Client) DoRaw(r Requester) ([]byte, uint64, error) {
req, err := r.Request()
if err != nil {
return nil, 0, err
}
c.replaceHost(req)
return c.doRequest(req)
}
// Do runs the request returned by the requestor and returns the parsed response
func (c *Client) Do(r Requester) (*Response, error) {
req, err := r.Request()
if err != nil {
return &Response{}, err
}
c.replaceHost(req)
body, statusCode, err := c.doRequest(req)
esResp := &Response{Status: statusCode}
if err != nil {
return esResp, err
}
if req.Method != "HEAD" {
err = json.Unmarshal(body, &esResp)
if err != nil {
return esResp, err
}
err = json.Unmarshal(body, &esResp.Raw)
if err != nil {
return esResp, err
}
}
if len(esResp.RawError) > 0 && esResp.RawError[0] == '"' {
json.Unmarshal(esResp.RawError, &esResp.Error)
} else {
esResp.Error = string(esResp.RawError)
}
esResp.RawError = nil
if esResp.Error != "" {
return esResp, &SearchError{esResp.Error, esResp.Status}
}
return esResp, nil
}
func (c *Client) doRequest(req *http.Request) ([]byte, uint64, error) {
resp, err := c.Client.Do(req)
if err != nil {
return nil, 0, err
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, uint64(resp.StatusCode), err
}
if resp.StatusCode > 201 && resp.StatusCode < 400 {
return nil, uint64(resp.StatusCode), errors.New(string(body))
}
return body, uint64(resp.StatusCode), nil
}