registrator.go

package registrator

import (
	"context"
	"time"

	"github.com/henderiw-k8s-lcnc/discovery/discovery"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/rest"
)

const (
	defaultWaitTime                  = 1 * time.Second
	defaultRegistrationCheckInterval = 10 * time.Second
	defaultMaxServiceFail            = 3
)

// Option can be used to manipulate Register config.
type Option func(Registrator)

type WatchOptions struct {
	// RetriveServices defines if service details are required
	// as part of ServiceResponse(s)
	RetriveServices bool
}

// TargetController defines the interfaces for the target controller
type Registrator interface {
	//options
	// add a logger to the Registrator
	//WithLogger(log logging.Logger)
	// Register
	Register(ctx context.Context, s *Service)
	// DeRegister
	DeRegister(ctx context.Context, id string)
	// Query
	Query(ctx context.Context, serviceName string, tags []string) ([]*Service, error)
	// GetEndpointAddress returns the address/port of the serviceEndpoint
	GetEndpointAddress(ctx context.Context, serviceName string, tags []string) (string, error)
	// Watch
	// 1 channel per service to watch
	Watch(ctx context.Context, serviceName string, tags []string, opts WatchOptions) chan *ServiceResponse
	// all services through 1 channel
	WatchCh(ctx context.Context, serviceName string, tags []string, opts WatchOptions, ch chan *ServiceResponse)
	//
	StopWatch(serviceName string)
}

type Service struct {
	Name         string       // service name
	ID           string       // service instance
	Port         int          // service port
	Address      string       // service address
	Tags         []string     // service tags
	HealthChecks []HealthKind // what type of health check kinds are needed to test the service
}

type ServiceResponse struct {
	ServiceName      string
	ServiceInstances []*Service
	Err              error
}

type HealthKind string

const (
	HealthKindTTL  HealthKind = "ttl"
	HealthKindGRPC HealthKind = "grpc"
)

type Options struct {
	//Scheme                    *runtime.Scheme
	ServiceDiscoveryDcName    string
	ServiceDiscovery          discovery.ServiceDiscoveryType
	ServiceDiscoveryNamespace string
	Address                   string
}

func New(ctx context.Context, config *rest.Config, o *Options) (Registrator, error) {
	switch o.ServiceDiscovery {
	case discovery.ServiceDiscoveryTypeK8s:
		c, err := kubernetes.NewForConfig(config)
		if err != nil {
			return nil, err
		}
		return newK8sRegistrator(ctx, c, o.ServiceDiscoveryNamespace)
	default:
		return newNopRegistrator(o), nil
	}
}