Add access format support for Elasticsearch notification target (#4006)

This change adds `access` format support for notifications to a
Elasticsearch server, and it refactors `namespace` format support.

In the case of `access` format, for each event in Minio, a JSON
document is inserted into Elasticsearch with its timestamp set to the
event's timestamp, and with the ID generated automatically by
elasticsearch. No events are modified or deleted in this mode.

In the case of `namespace` format, for each event in Minio, a JSON
document is keyed together by the bucket and object name is updated in
Elasticsearch. In the case of an object being created or over-written
in Minio, a new document or an existing document is inserted into the
Elasticsearch index. If an object is deleted in Minio, the
corresponding document is deleted from the Elasticsearch index.

Additionally, this change upgrades Elasticsearch support to the 5.x
series. This is a breaking change, and users of previous elasticsearch
versions should upgrade.

Also updates documentation on Elasticsearch notification target usage
and has a link to an elasticsearch upgrade guide.

This is the last patch that finally resolves #3928.

vendor/gopkg.in/olivere/elastic.v5/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/gopkg.in/olivere/elastic.v5/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/gopkg.in/olivere/elastic.v5/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)
+}