Get session info from srv

[FranckEtienne]

I launch an OpcUa server with srv.ListenAndServe().

When an OpcUa client connect, I would have an event or retreive information.

I try with :
if srv.ChannelManager().Len() > 0 {
ssc, ret := srv.ChannelManager().Get(0)
if ret {
fmt.Printf("ssc: %d; SecurityMode: TODO\n", ssc.ChannelID())
} else {
fmt.Printf("ssc: NIL !!!\n")
}
}

But, it's always retrun NIL :-(
What is the id in Get method: Get(id uint32)?
How can I retrieve it ?

Thank's a lot for your response and your job on OpcUa in Go :-)

[awcullen]

You pass the ChannelID to ChannelManger.Get(id uint32).
But the ChannelID's start at random number, not zero based.

I didn't plan for external access to channels and sessions or adding an event handler. Good idea!

Did you know about the option to add server diagnostics?

srv, err := server.New(
		...
		server.WithServerDiagnostics(true),
)

This adds nodes to the server namespace, for each open session.

[FranckEtienne]

Hi Andrew,
What I want to do is to have info about a client which connect to the server.
It is the case with WithServerDiagnostics?
Is it possible to trust a client which connect with X509 certificates?
Thank's for your response and your work.

[awcullen]

Hi Franck,
If you add option WithServerDiagnostics, the server will add nodes to the namespace that can be observed using an OPC client such as UAExpert.

Also, in the release v1.0.2 you will find client may activate a session with X509Identity. Server must be provided with function that checks X509Identity, returning nil if authenticated.

server.WithAuthenticateX509IdentityFunc(func(userIdentity ua.X509Identity, applicationURI string, endpointURL string) error {
	cert, err := x509.ParseCertificate([]byte(userIdentity.Certificate))
	if err != nil {
		return ua.BadUserAccessDenied
	}
	log.Printf("Login %s from %s\n", cert.Subject, applicationURI)
	return nil
}),