[MM-16768] Add support for Elasticsearch v7 (#12537)

* [MM-16768] Add support for Elasticsearch v7

* Fix i18n

* Adds external services tracking to the telemetry

* Rebuild elasticsearch interface mock

* Rename diagnostics keys

* Fix merge change

vendor/github.com/olivere/elastic/CONTRIBUTORS

@@ -0,0 +1,185 @@
+# This is a list of people who have contributed code
+# to the Elastic repository.
+#
+# It is just my small "thank you" to all those that helped
+# making Elastic what it is.
+#
+# Please keep this list sorted.
+
+0x6875790d0a [@huydx](https://github.com/huydx)
+Aaron Tami [@aarontami](https://github.com/aarontami)
+Adam Alix [@adamalix](https://github.com/adamalix)
+Adam Weiner [@adamweiner](https://github.com/adamweiner)
+Adrian Lungu [@AdrianLungu](https://github.com/AdrianLungu)
+alehano [@alehano](https://github.com/alehano)
+Alejandro Carstens [@alejandro-carstens](https://github.com/alejandro-carstens)
+Alex [@akotlar](https://github.com/akotlar)
+Alexander Sack [@asac](https://github.com/asac)
+Alexandre Olivier [@aliphen](https://github.com/aliphen)
+Alexey Sharov [@nizsheanez](https://github.com/nizsheanez)
+Anders [@ANerd](https://github.com/ANerd)
+AndreKR [@AndreKR](https://github.com/AndreKR)
+André Bierlein [@ligustah](https://github.com/ligustah)
+Andrew Dunham [@andrew-d](https://github.com/andrew-d)
+Andrew Gaul [@andrewgaul](https://github.com/andrewgaul)
+Andy Walker [@alaska](https://github.com/alaska)
+Arquivei [@arquivei](https://github.com/arquivei)
+Artemiy Elozhenko [@artezh](https://github.com/artezh)
+arthurgustin [@arthurgustin](https://github.com/arthurgustin)
+Bas van Dijk [@basvandijk](https://github.com/basvandijk)
+Benjamin Fernandes [@LotharSee](https://github.com/LotharSee)
+Benjamin Zarzycki [@kf6nux](https://github.com/kf6nux)
+Björn Gerdau [@kernle32dll](https://github.com/kernle32dll)
+Boris Popovschi [@Zyqsempai](https://github.com/Zyqsempai)
+Bowei Xu [@vancexu](https://github.com/vancexu)
+Braden Bassingthwaite [@bbassingthwaite-va](https://github.com/bbassingthwaite-va)
+Brady Love [@bradylove](https://github.com/bradylove)
+Bryan Conklin [@bmconklin](https://github.com/bmconklin)
+Bruce Zhou [@brucez-isell](https://github.com/brucez-isell)
+Carl Dunham [@carldunham](https://github.com/carldunham)
+Carl Johan Gustavsson [@cjgu](https://github.com/cjgu)
+Cat [@cat-turner](https://github.com/cat-turner)
+César Jiménez [@cesarjimenez](https://github.com/cesarjimenez)
+cforbes [@cforbes](https://github.com/cforbes)
+張泰瑋(Chang Tai Wei) [@david30907d](https://github.com/david30907d)
+Chris M [@tebriel](https://github.com/tebriel)
+Chris Rice [@donutmonger](https://github.com/donutmonger)
+Claudiu Olteanu [@claudiuolteanu](https://github.com/claudiuolteanu)
+Chris Duncan [@veqryn](https://github.com/veqryn)
+Chris Ludden [@cludden](https://github.com/cludden)
+Christophe Courtaut [@kri5](https://github.com/kri5)
+cmitchell [@cmitchell](https://github.com/cmitchell)
+Connor Peet [@connor4312](https://github.com/connor4312)
+Conrad Pankoff [@deoxxa](https://github.com/deoxxa)
+Corey Scott [@corsc](https://github.com/corsc)
+Chris Petersen [@ex-nerd](https://github.com/ex-nerd)
+Daniel Barrett [@shendaras](https://github.com/shendaras)
+Daniel Heckrath [@DanielHeckrath](https://github.com/DanielHeckrath)
+Daniel Imfeld [@dimfeld](https://github.com/dimfeld)
+Daniel Santos [@danlsgiga](https://github.com/danlsgiga)
+David Emanuel Buchmann [@wuurrd](https://github.com/wuurrd)
+Diego Becciolini [@itizir](https://github.com/itizir)
+Dwayne Schultz [@myshkin5](https://github.com/myshkin5)
+Elliot Williams [@elliotwms](https://github.com/elliotwms)
+Ellison Leão [@ellisonleao](https://github.com/ellisonleao)
+Erik Grinaker [@erikgrinaker](https://github.com/erikgrinaker)
+Erwin [@eticzon](https://github.com/eticzon)
+Etienne Lafarge [@elafarge](https://github.com/elafarge)
+Eugene Egorov [@EugeneEgorov](https://github.com/EugeneEgorov)
+Evan Shaw [@edsrzf](https://github.com/edsrzf)
+Fanfan [@wenpos](https://github.com/wenpos)
+Faolan C-P [@fcheslack](https://github.com/fcheslack)
+Filip Tepper [@filiptepper](https://github.com/filiptepper)
+Garrett Kelley [@GarrettKelley](https://github.com/GarrettKelley)
+Gaspard Douady [@plopik](https://github.com/plopik)
+Gaylord Aulke [@blafasel42](https://github.com/blafasel42)
+Gerhard Häring [@ghaering](https://github.com/ghaering)
+gregoryfranklin [@gregoryfranklin](https://github.com/gregoryfranklin)
+Guilherme Silveira [@guilherme-santos](https://github.com/guilherme-santos)
+Guillaume J. Charmes [@creack](https://github.com/creack)
+Guiseppe [@gm42](https://github.com/gm42)
+Han Yu [@MoonighT](https://github.com/MoonighT)
+Harmen [@alicebob](https://github.com/alicebob)
+Harrison Wright [@wright8191](https://github.com/wright8191)
+Henry Clifford [@hcliff](https://github.com/hcliff)
+Igor Dubinskiy [@idubinskiy](https://github.com/idubinskiy)
+initialcontext [@initialcontext](https://github.com/initialcontext)
+Isaac Saldana [@isaldana](https://github.com/isaldana)
+J Barkey Wolf [@jjhbw](https://github.com/jjhbw)
+Jack Lindamood [@cep21](https://github.com/cep21)
+Jacob [@jdelgad](https://github.com/jdelgad)
+Jan Düpmeier [@jduepmeier](https://github.com/jduepmeier)
+Jayme Rotsaert [@jrots](https://github.com/jrots)
+Jean-Alexandre Beaumont [@Enteris](https://github.com/Enteris)
+Jean-François Roche [@jfroche](https://github.com/jfroche)
+Jeff Rand [@jeffrand](https://github.com/jeffrand)
+Jeremy Canady [@jrmycanady](https://github.com/jrmycanady)
+Jérémie Vexiau [@texvex](https://github.com/texvex)
+Jesper Bränn [@Yopi](https://github.com/Yopi)
+Jim Berlage [@jimberlage](https://github.com/jimberlage)
+Joe Buck [@four2five](https://github.com/four2five)
+John Barker [@j16r](https://github.com/j16r)
+John Goodall [@jgoodall](https://github.com/jgoodall)
+John Stanford [@jxstanford](https://github.com/jxstanford)
+Jonas Groenaas Drange [@semafor](https://github.com/semafor)
+Josef Fröhle [@Dexus](https://github.com/Dexus)
+José Martínez [@xose](https://github.com/xose)
+Josh Chorlton [@jchorl](https://github.com/jchorl)
+Jpnock [@Jpnock](https://github.com/Jpnock)
+jun [@coseyo](https://github.com/coseyo)
+Junpei Tsuji [@jun06t](https://github.com/jun06t)
+kartlee [@kartlee](https://github.com/kartlee)
+Keith Hatton [@khatton-ft](https://github.com/khatton-ft)
+kel [@liketic](https://github.com/liketic)
+Kenta SUZUKI [@suzuken](https://github.com/suzuken)
+Kevin Mulvey [@kmulvey](https://github.com/kmulvey)
+Kyle Brandt [@kylebrandt](https://github.com/kylebrandt)
+Larry Cinnabar [@larrycinnabar](https://github.com/larrycinnabar)
+Leandro Piccilli [@lpic10](https://github.com/lpic10)
+Lee [@leezhm](https://github.com/leezhm)
+lechnertech [@lechnertech](https://github.com/lechnertech)
+M. Zulfa Achsani [@misterciput](https://github.com/misterciput)
+Maciej Lisiewski [@c2h5oh](https://github.com/c2h5oh)
+Mara Kim [@autochthe](https://github.com/autochthe)
+Marcy Buccellato [@marcybuccellato](https://github.com/marcybuccellato)
+Mark Costello [@mcos](https://github.com/mcos)
+Martin Häger [@protomouse](https://github.com/protomouse)
+Matt Braymer-Hayes [@mattayes](https://github.com/mattayes)
+Medhi Bechina [@mdzor](https://github.com/mdzor)
+Mike Beshai [@mbesh](https://github.com/mbesh)
+mmfrb [@mmfrb](https://github.com/mmfrb)
+mnpritula [@mnpritula](https://github.com/mnpritula)
+mosa [@mosasiru](https://github.com/mosasiru)
+Muhammet Çakır [@cakirmuha](https://github.com/cakirmuha)
+naimulhaider [@naimulhaider](https://github.com/naimulhaider)
+Naoya Yoshizawa [@azihsoyn](https://github.com/azihsoyn)
+navins [@ishare](https://github.com/ishare)
+Naoya Tsutsumi [@tutuming](https://github.com/tutuming)
+NeoCN [@NeoCN](https://github.com/NeoCN)
+Nicholas Wolff [@nwolff](https://github.com/nwolff)
+Nick K [@utrack](https://github.com/utrack)
+Nick Whyte [@nickw444](https://github.com/nickw444)
+Nicolae Vartolomei [@nvartolomei](https://github.com/nvartolomei)
+okhowang [@okhowang](https://github.com/okhowang)
+Orne Brocaar [@brocaar](https://github.com/brocaar)
+Paul [@eyeamera](https://github.com/eyeamera)
+Paul Oldenburg [@lr-paul](https://github.com/lr-paul)
+Pete C [@peteclark-ft](https://github.com/peteclark-ft)
+Peter Nagy [@nagypeterjob](https://github.com/nagypeterjob)
+Paolo [@ppiccolo](https://github.com/ppiccolo)
+Radoslaw Wesolowski [@r--w](https://github.com/r--w)
+Rafał Gałus [@rgalus](https://github.com/rgalus)
+rchicoli [@rchicoli](https://github.com/rchicoli)
+Roman Colohanin [@zuzmic](https://github.com/zuzmic)
+Ryan Schmukler [@rschmukler](https://github.com/rschmukler)
+Ryan Wynn [@rwynn](https://github.com/rwynn)
+Sacheendra talluri [@sacheendra](https://github.com/sacheendra)
+Sean DuBois [@Sean-Der](https://github.com/Sean-Der)
+Sagan Yaroslav [@sgnrslv](https://github.com/sgnrslv)
+Shalin LK [@shalinlk](https://github.com/shalinlk)
+singham [@zhaochenxiao90](https://github.com/zhaochenxiao90)
+Slawomir CALUCH [@slawo](https://github.com/slawo)
+soarpenguin [@soarpenguin](https://github.com/soarpenguin)
+Stephan Krynauw [@skrynauw](https://github.com/skrynauw)
+Stephen Kubovic [@stephenkubovic](https://github.com/stephenkubovic)
+Stuart Warren [@Woz](https://github.com/stuart-warren)
+Sulaiman [@salajlan](https://github.com/salajlan)
+Sundar [@sundarv85](https://github.com/sundarv85)
+Swarlston [@Swarlston](https://github.com/Swarlston)
+Take [ww24](https://github.com/ww24)
+Tetsuya Morimoto [@t2y](https://github.com/t2y)
+TheZeroSlave [@TheZeroSlave](https://github.com/TheZeroSlave)
+Tomasz Elendt [@telendt](https://github.com/telendt)
+TimeEmit [@TimeEmit](https://github.com/timeemit)
+TusharM [@tusharm](https://github.com/tusharm)
+wangtuo [@wangtuo](https://github.com/wangtuo)
+Wédney Yuri [@wedneyyuri](https://github.com/wedneyyuri)
+Wesley Kim [@wesleyk](https://github.com/wesleyk)
+wolfkdy [@wolfkdy](https://github.com/wolfkdy)
+Wyndham Blanton [@wyndhblb](https://github.com/wyndhblb)
+Yarden Bar [@ayashjorden](https://github.com/ayashjorden)
+Yuya Kusakabe [@higebu](https://github.com/higebu)
+zakthomas [@zakthomas](https://github.com/zakthomas)
+Zach [@snowzach](https://github.com/snowzach)
+zhangxin [@visaxin](https://github.com/visaxin)
+@林 [@zplzpl](https://github.com/zplzpl)

vendor/github.com/olivere/elastic/LICENSE

@@ -0,0 +1,20 @@
+The MIT License (MIT)
+Copyright © 2012-2015 Oliver Eilhard
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the “Software”), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+IN THE SOFTWARE.

vendor/github.com/olivere/elastic/config/config.go

@@ -0,0 +1,87 @@
+// 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 config
+
+import (
+	"fmt"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+// Config represents an Elasticsearch configuration.
+type Config struct {
+	URL         string
+	Index       string
+	Username    string
+	Password    string
+	Shards      int
+	Replicas    int
+	Sniff       *bool
+	Healthcheck *bool
+	Infolog     string
+	Errorlog    string
+	Tracelog    string
+}
+
+// Parse returns the Elasticsearch configuration by extracting it
+// from the URL, its path, and its query string.
+//
+// Example:
+//   http://127.0.0.1:9200/store-blobs?shards=1&replicas=0&sniff=false&tracelog=elastic.trace.log
+//
+// The code above will return a URL of http://127.0.0.1:9200, an index name
+// of store-blobs, and the related settings from the query string.
+func Parse(elasticURL string) (*Config, error) {
+	cfg := &Config{
+		Shards:   1,
+		Replicas: 0,
+		Sniff:    nil,
+	}
+
+	uri, err := url.Parse(elasticURL)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing elastic parameter %q: %v", elasticURL, err)
+	}
+	index := strings.TrimSuffix(strings.TrimPrefix(uri.Path, "/"), "/")
+	if uri.User != nil {
+		cfg.Username = uri.User.Username()
+		cfg.Password, _ = uri.User.Password()
+	}
+	uri.User = nil
+
+	if i, err := strconv.Atoi(uri.Query().Get("shards")); err == nil {
+		cfg.Shards = i
+	}
+	if i, err := strconv.Atoi(uri.Query().Get("replicas")); err == nil {
+		cfg.Replicas = i
+	}
+	if s := uri.Query().Get("sniff"); s != "" {
+		if b, err := strconv.ParseBool(s); err == nil {
+			cfg.Sniff = &b
+		}
+	}
+	if s := uri.Query().Get("healthcheck"); s != "" {
+		if b, err := strconv.ParseBool(s); err == nil {
+			cfg.Healthcheck = &b
+		}
+	}
+	if s := uri.Query().Get("infolog"); s != "" {
+		cfg.Infolog = s
+	}
+	if s := uri.Query().Get("errorlog"); s != "" {
+		cfg.Errorlog = s
+	}
+	if s := uri.Query().Get("tracelog"); s != "" {
+		cfg.Tracelog = s
+	}
+
+	uri.Path = ""
+	uri.RawQuery = ""
+	cfg.URL = uri.String()
+	cfg.Index = index
+
+	return cfg, nil
+}

vendor/github.com/olivere/elastic/config/doc.go

@@ -0,0 +1,9 @@
+// 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 config allows parsing a configuration for Elasticsearch
+from a URL.
+*/
+package config

vendor/github.com/olivere/elastic/uritemplates/LICENSE

@@ -0,0 +1,18 @@
+Copyright (c) 2013 Joshua Tacoma
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/olivere/elastic/uritemplates/uritemplates.go

@@ -0,0 +1,359 @@
+// Copyright 2013 Joshua Tacoma. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package uritemplates is a level 4 implementation of RFC 6570 (URI
+// Template, http://tools.ietf.org/html/rfc6570).
+//
+// To use uritemplates, parse a template string and expand it with a value
+// map:
+//
+//	template, _ := uritemplates.Parse("https://api.github.com/repos{/user,repo}")
+//	values := make(map[string]interface{})
+//	values["user"] = "jtacoma"
+//	values["repo"] = "uritemplates"
+//	expanded, _ := template.ExpandString(values)
+//	fmt.Printf(expanded)
+//
+package uritemplates
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var (
+	unreserved = regexp.MustCompile("[^A-Za-z0-9\\-._~]")
+	reserved   = regexp.MustCompile("[^A-Za-z0-9\\-._~:/?#[\\]@!$&'()*+,;=]")
+	validname  = regexp.MustCompile("^([A-Za-z0-9_\\.]|%[0-9A-Fa-f][0-9A-Fa-f])+$")
+	hex        = []byte("0123456789ABCDEF")
+)
+
+func pctEncode(src []byte) []byte {
+	dst := make([]byte, len(src)*3)
+	for i, b := range src {
+		buf := dst[i*3 : i*3+3]
+		buf[0] = 0x25
+		buf[1] = hex[b/16]
+		buf[2] = hex[b%16]
+	}
+	return dst
+}
+
+func escape(s string, allowReserved bool) (escaped string) {
+	if allowReserved {
+		escaped = string(reserved.ReplaceAllFunc([]byte(s), pctEncode))
+	} else {
+		escaped = string(unreserved.ReplaceAllFunc([]byte(s), pctEncode))
+	}
+	return escaped
+}
+
+// A UriTemplate is a parsed representation of a URI template.
+type UriTemplate struct {
+	raw   string
+	parts []templatePart
+}
+
+// Parse parses a URI template string into a UriTemplate object.
+func Parse(rawtemplate string) (template *UriTemplate, err error) {
+	template = new(UriTemplate)
+	template.raw = rawtemplate
+	split := strings.Split(rawtemplate, "{")
+	template.parts = make([]templatePart, len(split)*2-1)
+	for i, s := range split {
+		if i == 0 {
+			if strings.Contains(s, "}") {
+				err = errors.New("unexpected }")
+				break
+			}
+			template.parts[i].raw = s
+		} else {
+			subsplit := strings.Split(s, "}")
+			if len(subsplit) != 2 {
+				err = errors.New("malformed template")
+				break
+			}
+			expression := subsplit[0]
+			template.parts[i*2-1], err = parseExpression(expression)
+			if err != nil {
+				break
+			}
+			template.parts[i*2].raw = subsplit[1]
+		}
+	}
+	if err != nil {
+		template = nil
+	}
+	return template, err
+}
+
+type templatePart struct {
+	raw           string
+	terms         []templateTerm
+	first         string
+	sep           string
+	named         bool
+	ifemp         string
+	allowReserved bool
+}
+
+type templateTerm struct {
+	name     string
+	explode  bool
+	truncate int
+}
+
+func parseExpression(expression string) (result templatePart, err error) {
+	switch expression[0] {
+	case '+':
+		result.sep = ","
+		result.allowReserved = true
+		expression = expression[1:]
+	case '.':
+		result.first = "."
+		result.sep = "."
+		expression = expression[1:]
+	case '/':
+		result.first = "/"
+		result.sep = "/"
+		expression = expression[1:]
+	case ';':
+		result.first = ";"
+		result.sep = ";"
+		result.named = true
+		expression = expression[1:]
+	case '?':
+		result.first = "?"
+		result.sep = "&"
+		result.named = true
+		result.ifemp = "="
+		expression = expression[1:]
+	case '&':
+		result.first = "&"
+		result.sep = "&"
+		result.named = true
+		result.ifemp = "="
+		expression = expression[1:]
+	case '#':
+		result.first = "#"
+		result.sep = ","
+		result.allowReserved = true
+		expression = expression[1:]
+	default:
+		result.sep = ","
+	}
+	rawterms := strings.Split(expression, ",")
+	result.terms = make([]templateTerm, len(rawterms))
+	for i, raw := range rawterms {
+		result.terms[i], err = parseTerm(raw)
+		if err != nil {
+			break
+		}
+	}
+	return result, err
+}
+
+func parseTerm(term string) (result templateTerm, err error) {
+	if strings.HasSuffix(term, "*") {
+		result.explode = true
+		term = term[:len(term)-1]
+	}
+	split := strings.Split(term, ":")
+	if len(split) == 1 {
+		result.name = term
+	} else if len(split) == 2 {
+		result.name = split[0]
+		var parsed int64
+		parsed, err = strconv.ParseInt(split[1], 10, 0)
+		result.truncate = int(parsed)
+	} else {
+		err = errors.New("multiple colons in same term")
+	}
+	if !validname.MatchString(result.name) {
+		err = errors.New("not a valid name: " + result.name)
+	}
+	if result.explode && result.truncate > 0 {
+		err = errors.New("both explode and prefix modifers on same term")
+	}
+	return result, err
+}
+
+// Expand expands a URI template with a set of values to produce a string.
+func (self *UriTemplate) Expand(value interface{}) (string, error) {
+	values, ismap := value.(map[string]interface{})
+	if !ismap {
+		if m, ismap := struct2map(value); !ismap {
+			return "", errors.New("expected map[string]interface{}, struct, or pointer to struct.")
+		} else {
+			return self.Expand(m)
+		}
+	}
+	var buf bytes.Buffer
+	for _, p := range self.parts {
+		err := p.expand(&buf, values)
+		if err != nil {
+			return "", err
+		}
+	}
+	return buf.String(), nil
+}
+
+func (self *templatePart) expand(buf *bytes.Buffer, values map[string]interface{}) error {
+	if len(self.raw) > 0 {
+		buf.WriteString(self.raw)
+		return nil
+	}
+	var zeroLen = buf.Len()
+	buf.WriteString(self.first)
+	var firstLen = buf.Len()
+	for _, term := range self.terms {
+		value, exists := values[term.name]
+		if !exists {
+			continue
+		}
+		if buf.Len() != firstLen {
+			buf.WriteString(self.sep)
+		}
+		switch v := value.(type) {
+		case string:
+			self.expandString(buf, term, v)
+		case []interface{}:
+			self.expandArray(buf, term, v)
+		case map[string]interface{}:
+			if term.truncate > 0 {
+				return errors.New("cannot truncate a map expansion")
+			}
+			self.expandMap(buf, term, v)
+		default:
+			if m, ismap := struct2map(value); ismap {
+				if term.truncate > 0 {
+					return errors.New("cannot truncate a map expansion")
+				}
+				self.expandMap(buf, term, m)
+			} else {
+				str := fmt.Sprintf("%v", value)
+				self.expandString(buf, term, str)
+			}
+		}
+	}
+	if buf.Len() == firstLen {
+		original := buf.Bytes()[:zeroLen]
+		buf.Reset()
+		buf.Write(original)
+	}
+	return nil
+}
+
+func (self *templatePart) expandName(buf *bytes.Buffer, name string, empty bool) {
+	if self.named {
+		buf.WriteString(name)
+		if empty {
+			buf.WriteString(self.ifemp)
+		} else {
+			buf.WriteString("=")
+		}
+	}
+}
+
+func (self *templatePart) expandString(buf *bytes.Buffer, t templateTerm, s string) {
+	if len(s) > t.truncate && t.truncate > 0 {
+		s = s[:t.truncate]
+	}
+	self.expandName(buf, t.name, len(s) == 0)
+	buf.WriteString(escape(s, self.allowReserved))
+}
+
+func (self *templatePart) expandArray(buf *bytes.Buffer, t templateTerm, a []interface{}) {
+	if len(a) == 0 {
+		return
+	} else if !t.explode {
+		self.expandName(buf, t.name, false)
+	}
+	for i, value := range a {
+		if t.explode && i > 0 {
+			buf.WriteString(self.sep)
+		} else if i > 0 {
+			buf.WriteString(",")
+		}
+		var s string
+		switch v := value.(type) {
+		case string:
+			s = v
+		default:
+			s = fmt.Sprintf("%v", v)
+		}
+		if len(s) > t.truncate && t.truncate > 0 {
+			s = s[:t.truncate]
+		}
+		if self.named && t.explode {
+			self.expandName(buf, t.name, len(s) == 0)
+		}
+		buf.WriteString(escape(s, self.allowReserved))
+	}
+}
+
+func (self *templatePart) expandMap(buf *bytes.Buffer, t templateTerm, m map[string]interface{}) {
+	if len(m) == 0 {
+		return
+	}
+	if !t.explode {
+		self.expandName(buf, t.name, len(m) == 0)
+	}
+	var firstLen = buf.Len()
+	for k, value := range m {
+		if firstLen != buf.Len() {
+			if t.explode {
+				buf.WriteString(self.sep)
+			} else {
+				buf.WriteString(",")
+			}
+		}
+		var s string
+		switch v := value.(type) {
+		case string:
+			s = v
+		default:
+			s = fmt.Sprintf("%v", v)
+		}
+		if t.explode {
+			buf.WriteString(escape(k, self.allowReserved))
+			buf.WriteRune('=')
+			buf.WriteString(escape(s, self.allowReserved))
+		} else {
+			buf.WriteString(escape(k, self.allowReserved))
+			buf.WriteRune(',')
+			buf.WriteString(escape(s, self.allowReserved))
+		}
+	}
+}
+
+func struct2map(v interface{}) (map[string]interface{}, bool) {
+	value := reflect.ValueOf(v)
+	switch value.Type().Kind() {
+	case reflect.Ptr:
+		return struct2map(value.Elem().Interface())
+	case reflect.Struct:
+		m := make(map[string]interface{})
+		for i := 0; i < value.NumField(); i++ {
+			tag := value.Type().Field(i).Tag
+			var name string
+			if strings.Contains(string(tag), ":") {
+				name = tag.Get("uri")
+			} else {
+				name = strings.TrimSpace(string(tag))
+			}
+			if len(name) == 0 {
+				name = value.Type().Field(i).Name
+			}
+			m[name] = value.Field(i).Interface()
+		}
+		return m, true
+	}
+	return nil, false
+}

vendor/github.com/olivere/elastic/uritemplates/utils.go

@@ -0,0 +1,13 @@
+package uritemplates
+
+func Expand(path string, expansions map[string]string) (string, error) {
+	template, err := Parse(path)
+	if err != nil {
+		return "", err
+	}
+	values := make(map[string]interface{})
+	for k, v := range expansions {
+		values[k] = v
+	}
+	return template.Expand(values)
+}