Connection.Start is deprecated without alternative

[dornimaug]

As discussed in #356 and implemented in #499 the Connection.Start function has been deprecated, but there is now no way to use net.DialContext instead of one of the ldap.Dial-functions. We currently initialize connections this way:

	dialer := tls.Dialer{
		...
	}
	netConn, err := dialer.DialContext(ctx, "tcp", server)
	if err != nil {
		...
	}
	c := ldap.NewConn(netConn, true)
	c.SetTimeout(readTimeout)
	c.Start()

How can the same (using DialContext and setting a timeout) be achieved through non-deprecated APIs of the ldap package?

Should ldap.NewConn not have been deprecated alongside Connection.Start or is there any legitimate way left to use it?

[cpuschma]

NewConn will be marked deprecated as well in the next release. You can use DialWithDialer to specify a custom dialer to use:

ldap/conn.go

Lines 130 to 135 in 2260012

	// DialWithDialer updates net.Dialer in DialContext.
	func DialWithDialer(d *net.Dialer) DialOpt {
	return func(dc *DialContext) {
	dc.dialer = d
	}
	}

You can use the connection option in Dial, DialTLS or DialURL:

ldap/v3/conn.go

Lines 225 to 229 in 2260012

	// DialURL connects to the given ldap URL.
	// The following schemas are supported: ldap://, ldaps://, ldapi://,
	// and cldap:// (RFC1798, deprecated but used by Active Directory).
	// On success a new Conn for the connection is returned.
	func DialURL(addr string, opts ...DialOpt) (*Conn, error) {

[dornimaug]

There is no DialOpt to provide a context.Context to be used together with a net.Dialer's DialContext function. go-ldap currently uses Dial functions and never DialContext. So there is still no way to implement the same functionality as in my code snippet using non-deprecated APIs.
The use of DialContext/context.Context is necessary to make cancellation of the dial operation possible.

[cpuschma]

Agreed. Context implementation is still open and mostly unfinished (see #406). I'll consider revertig the deprecation, as we didn't thought of this use case. Sorry for any inconveniences. The function should work just fine in the meantime.

[gustavoluvizotto]

Hi,
Please see #356 (comment)

[cpuschma]

I just released a new version with the reverted commit: https://github.com/go-ldap/ldap/releases/tag/v3.4.8

Again, thank you for pointing this out, I'm sorry for any inconveniences.