fix(client): force Event Hubs to use V1_0_0_0 (#2633)

The problem with supporting Azure Event Hubs is that it isn't Apache
Kafka under the covers, it's an intermediate proxy that supports a
subset of the Kafka APIs at various versions and then maps them onto
Event Hubs protocol(s) at the backend. As as result Sarama's current
mechanism of specifying the KAFKA_VERSION to determine what protocol
versions to support and use doesn't really work properly with Event Hubs
because it supports an unusual set of protocols and even defines minimum
versions for ProduceRequest (v3) and FetchRequest (v4). For some reason
EventHubs is very behind on FetchRequest and MetadataRequest so the max
configuration you can use in Sarama is V1_0_0_0 and the minimum is
V0_11_0_0.

As we have recently bumped the default Version to V2_1_0_0 and support a
wider range of protocol versions, we're more likely to see issues raised
by Event Hubs users unless they have already pinned their version
correctly. To try and prevent this, attempt to detect use with Event
Hubs by inspecting the bootstrap broker addresses and overriding the
Version.

Contributes-to: #2470

Signed-off-by: Dominic Evans <dominic.evans@uk.ibm.com>

client.go

@@ -183,6 +183,13 @@ func NewClient(addrs []string, conf *Config) (Client, error) {
 		return nil, ConfigurationError("You must provide at least one broker address")
 	}
 
+	if strings.Contains(addrs[0], ".servicebus.windows.net") {
+		if conf.Version.IsAtLeast(V1_1_0_0) || !conf.Version.IsAtLeast(V0_11_0_0) {
+			Logger.Println("Connecting to Azure Event Hubs, forcing version to V1_0_0_0 for compatibility")
+			conf.Version = V1_0_0_0
+		}
+	}
+
 	client := &client{
 		conf:                    conf,
 		closer:                  make(chan none),