RFC: Persistent Search

[vetinari]

There's an initial implementation of persistent search (https://www.ietf.org/proceedings/50/I-D/ldapext-psearch-03.txt) in https://github.com/vetinari/ldap/tree/persistent-search

That one works e.g. with an OpenDJ (or OpenDS probably) which supports this control(s)

Code to get it running:

package main
import (
    "crypto/tls"
    "fmt"
    "gopkg.in/ldap.v2"
)

func main() {
    l, err := ldap.DialTLS("tcp", "ldap.example.org:636", &tls.Config{InsecureSkipVerify: true})
    if err != nil {
        panic("DialTLS: " + err.Error())
    }
    _, err = l.SimpleBind(ldap.NewSimpleBindRequest("uid=someone,dc=example,dc=org", "MySecret", nil))
    if err != nil {
        panic("SimpleBind(): " + err.Error())
    }
    req := &ldap.SearchRequest{
        BaseDN:     "ou=people,dc=example,dc=org",
        Scope:      ldap.ScopeWholeSubtree,
        Filter:     "(uid=*)",
        Attributes: []string{"uid", "cn"},
    }
    l.Debug = true
    err = l.PersistentSearch(req, []string{"any"}, true, true, callBack)
    if err != nil {
        panic("PersistentSearch(): " + err.Error())
    }
}

func callBack(res *ldap.SearchResult) bool {
    if len(res.Entries) != 0 {
        entry := res.Entries[0]
        fmt.Printf("%s (%s)\n", entry.GetAttributeValue("cn"), entry.GetAttributeValue("uid"))
    }
    if len(res.Controls) != 0 {
        fmt.Printf("CTRL=%s\n", res.Controls[0].String())
    }
    return true
}

Note that the PersistentSearch() will never (except for errors) return.
When this is running any changes on "uid" or "cn" will cause the "callBack()" function to run.

[vetinari]

see also #80