custom connection type

[carr123]

hi, i want to add my own connection type, currently i need to modify your code at github.com\eclipse\paho.mqtt.golang\netconn.go in openConnection function, add a new case branch.

case "haha":
       conn, err := HahaConnect(uri.Host, timeout)
       return conn, err

is there a better way to do that, without modifying your code ?
thanks.

[MattBrittan]

Unfortunately there is currently no way of achieving this without modifying the library itself. If your broker supports MQTT v5 I'd suggest taking a look at the v5 client because it's design does allow this kind of thing.

[carr123]

my broker doesn't supports MQTTv5.
do you hava any plan to support this feature in this library ？

[MattBrittan]

It's not something I plan to add (you are the first person I've heard from who has a need for this). If you feel that you can add this in a way that does not impact other functionality or add too much complexity then please feel free to submit a pull request.

[carr123]

hi, i hava added this feature and submit a PR.

[hub-adda]

Hello, we are interested in such a feature as well, as we look to use OpenSSL TLS library instead of golang default one. @carr123 is it possible to contribute to that PR?
thanks Gil

[MattBrittan]

@GilAddaCyberark see PR #569 - @carr123 submitted that PR but I've suggested an alternative implementation. Would be interested in your thoughts on this (had seen it as a very niche request so was keen for a very generic solution).

[hub-adda]

Hi @MattBrittan thanks for sharing and referring to the need. I looked at PR #569 and is seems fine to our use case. I assume that we can convert tls.config params to openssl context parameters (well, tls is tls). however have a concern that there will be a need other parameters for future transport types.
May I suggest a slight modification to it (hope that i'm getting things right):

// connectionArgs is an array of future transport parameters
type openConnectionFunc func(uri *url.URL, ... , connectionArgs ...interface{}) (net.Conn, error)

or maybe do it the ClientOptions way:
type openConnectionFunc func(uri *url.URL, options *ClientOptions , connectionArgs ...interface{}) (net.Conn, error)

[MattBrittan]

Thanks @GilAddaCyberark - unfortunately that doesn't work because there is no mechanism to pass the connectionArgs into the library (we don't want to break existing usages so are not changing the API). Having said that you can still accomplish this by passing in a member function (e.g. Setup type foo struct { connectionArg interface{} } func (f *foo) Connect (net.Conn, Error) Connect { // connetc using the args} then pass f.Connect into SetOpenConnectionFunc.

[carrish]

@GilAddaCyberark hi, i(carr123) encounter some problem to summit a PR.
you can summit your PR. refer to #571
good luck.

[MattBrittan]

I have accepted PR #574 which I believe should resolve this request.

[carr123]

@MattBrittan very good ! thanks.