Return error on clickhouse.Open with protocol HTTP.

[pashagoose]

I have noticed that setting protocol HTTP in clickhouse.Options does not affect the behaviour: still the connection is being setup with native clickhouse protocol. This may be confusing for users.

Especially when they see this error: [handshake] unexpected packet [72] from server. I have had this problem when trying to connect to HTTP clickhouse endpoint using clickhouse.Open(&clickhouse.Options{Protocol: clickhouse.HTTP, ...}).

Is it possible to return error from clickhouse.Open which highlights that http is unsupported if it is specified ?

links to source code:
http clickhouse protocol: https://github.com/ClickHouse/clickhouse-go/blob/main/clickhouse_options.go#L103
dial function:

clickhouse-go/conn.go

Line 40 in 5ebfd0c

func dial(ctx context.Context, addr string, num int, opt *Options) (*connect, error) {

- it assumes native clickhouse protocol

[SpencerTorres]

Yeah this is easy to forget, it should have returned an error.

I was so shocked by this feature gap that I just decided to add it the other weekend. Now we support HTTP in clickhouse.Open: #1577

Available in the v2.37.x release