Can the Consul API SDK support custom QueryOptions

[shenqidebaozi]

Feature Description

When I use the Watch package in the Consul API, I want to listen for instance update events of the peer cluster through Watch, but it does not support specifying the peer parameter, so I cannot listen for instance information of the peer cluster.

	parse, err := watch.Parse(map[string]interface{}{
		"type":        "service",
		"service":     "xxxxx",
		"passingonly": true,
		"peer":        "xxxxxx",
	})
	if err != nil {
		t.Fatal(err)
	}

	parse.HybridHandler = func(val watch.BlockingParamVal, i interface{}) {
		s := i.([]*api.ServiceEntry)
		for _, entry := range s {
			fmt.Println(entry.Service.Address, entry.Service.Port, entry.Service.Meta)
		}
	}
	
	parse.RunWithClientAndHclog(consul, hclog.L())

Invalid parameters: [peer]

Use Case(s)

I would like to add a configuration for QueryOptions in the plan to specify the default QueryOptions

consul/api/watch/watch.go

Line 24 in 2f33511

type Plan struct {

type Plan struct {
	Datacenter  string
	Token       string
	Type        string
	HandlerType string
	Exempt      map[string]interface{}

	Watcher WatcherFunc
	// Handler is kept for backward compatibility but only supports watches based
	// on index param. To support hash based watches, set HybridHandler instead.
	Handler       HandlerFunc
	HybridHandler HybridHandlerFunc

	Logger hclog.Logger
	// Deprecated: use Logger
	LogOutput io.Writer

	address      string
	client       *consulapi.Client
	lastParamVal BlockingParamVal
	lastResult   interface{}
        QueryOtions  *consuapi.QueryOptions // used to specify default QueryOptions

	stop       bool
	stopCh     chan struct{}
	stopLock   sync.Mutex
	cancelFunc context.CancelFunc
}

consul/api/watch/funcs.go

Line 340 in 2f33511

func makeQueryOptionsWithContext(p *Plan, stale bool) consulapi.QueryOptions {

func makeQueryOptionsWithContext(p *Plan, stale bool) consulapi.QueryOptions {
	ctx, cancel := context.WithCancel(context.Background())
	p.setCancelFunc(cancel)
	opts := p.QueryOtions
        opts.AllowStale = stale
	switch param := p.lastParamVal.(type) {
	case WaitIndexVal:
		opts.WaitIndex = uint64(param)
	case WaitHashVal:
		opts.WaitHash = string(param)
	}
	return *opts.WithContext(ctx)
}

If we think this is meaningful, please assign it to me

[shcw]

非常有用 大佬请做个demo 在kratos的example中

[huikang]

@shenqidebaozi , thanks for the proposal. Do you mind elaborating on how the QueryOptions can solve the peering parameter in your example?

[shenqidebaozi]

@huikang Of course, I will create a PR to implement this feature

[shenqidebaozi]

@huikang I have submitted a PR，through this feature, users can specify QueryOptions themselves without adding various watch parameters