Add example for paging search result attributes, maybe?

[naikrovek]

Hi, I need to page the attribute results of a search with a single result; it's a large group and I need all members ("member" attribute, though I think this gets appended with an offset and count if you want to page; something like member;range=0-499.)

I can't figure this out for the life of me, so maybe an example is needed to help anyone else with this need, if the library supports this. otherwise I can just do the paging myself and loop over the query over and over until no more results are returned.

[bhaswanth88]

@naikrovek : i am also looking for same, have you found an answer for this? if so, can you please share ?

[naikrovek]

Here's an example program. This uses recursion to get nested group members as well. if you have a circularly nested groups underneath the group specified in main then this will run for a very long time, and eventually fail.

package main

import (
	"fmt"
	"log"
	"strconv"
	"strings"

	"github.com/go-ldap/ldap/v3"
)

func main() {
	// this will get members of nested groups as well.  beware circular nesting.
	members := getLdapGroupMembers("groupname")

	results := make(map[string]bool)

	for _, member := range members {
		results[member] = true
	}

	for key := range results {
		fmt.Println(key)
	}
}

func check(e error) {
	if e != nil {
		log.Panic(e)
	}
}

func getLdapGroupMembers(group string) []string {
	l, err := ldap.DialURL("ldaps://adcontroller.domain:636")
	check(err)

	defer l.Close()

	bindpass := "asdfasdf" 

	err = l.Bind("CN=asdf,OU=asdf,OU=asdf,DC=asdf,DC=asdf,DC=asdf", bindpass)
	check(err)

	stepSize := 500
	lowNumber := 0
	highNumber := lowNumber + stepSize - 1

	keepGoing := true

	searchBase := "OU=asdf,OU=asdf,DC=asdf,DC=asdf,DC=asdf"
	filter := "(&(objectClass=group)(cn=" + ldap.EscapeFilter(group) + "))"
	pagingControl := ldap.NewControlPaging(uint32(stepSize))
	controls := []ldap.Control{pagingControl}

	results := []string{}

	for keepGoing {
		attributeString := "member;range=" + strconv.Itoa(lowNumber) + "-" + strconv.Itoa(highNumber)
		attributes := []string{"cn", attributeString}

		lowNumber += stepSize
		highNumber += stepSize

		searchRequest := ldap.NewSearchRequest(
			searchBase,
			ldap.ScopeWholeSubtree, ldap.DerefAlways, 0, 0, false,
			filter,
			attributes,
			controls,
		)

		response, err := l.Search(searchRequest)
		check(err)

		for _, entry := range response.Entries {
			if len(entry.Attributes) < 2 {
				keepGoing = false
				continue
			}

			for _, attribute := range entry.Attributes {
				if strings.HasPrefix(attribute.Name, "memb") {
					members := entry.GetAttributeValues(attribute.Name)
					// walk the results and add them to results.  if any are
					// groups, get the users in that group.
					for _, result := range members {
						if strings.Contains(result, "OU=asdf") {
							groupName := strings.Replace(result, "CN=", "", -1)
							groupName = strings.Replace(groupName, ",OU=asdf,OU=asdf,DC=asdf,DC=asdf,DC=asdf", "", -1)
							groupUsers := getLdapGroupMembers(groupName)
							results = append(results, groupUsers...)
						} else {
							// a normal user
							results = append(results, result)
						}
					}

					if len(members) < int(stepSize) {
						keepGoing = false
					}
				}
			}
		}
	}

	return results
}