gsvc

type Discovery interface {
	// Search searches and returns services with specified condition.
	Search(ctx context.Context, in SearchInput) (result []Service, err error)

	// Watch watches specified condition changes.
	// The `key` is the prefix of service key.
	Watch(ctx context.Context, key string) (watcher Watcher, err error)
}

type Endpoint interface {
	// Host returns the IPv4/IPv6 address of a service.
	Host() string

	// Port returns the port of a service.
	Port() int

	// String formats and returns the Endpoint as a string.
	String() string
}

type Endpoints []Endpoint

type LocalEndpoint struct {
	// contains filtered or unexported fields
}

type LocalService struct {
	Head       string    // Service custom head string in service key.
	Deployment string    // Service deployment name, eg: dev, qa, staging, prod, etc.
	Namespace  string    // Service Namespace, to indicate different services in the same environment with the same Name.
	Name       string    // Name for the service.
	Version    string    // Service version, eg: v1.0.0, v2.1.1, etc.
	Endpoints  Endpoints // Service Endpoints, pattern: IP:port, eg: 192.168.1.2:8000.
	Metadata   Metadata  // Custom data for this service, which can be set using JSON by environment or command-line.
}

type Metadata map[string]interface{}

type Registrar interface {
	// Register registers `service` to Registry.
	// Note that it returns a new Service if it changes the input Service with custom one.
	Register(ctx context.Context, service Service) (registered Service, err error)

	// Deregister off-lines and removes `service` from the Registry.
	Deregister(ctx context.Context, service Service) error
}

type Registry interface {
	Registrar
	Discovery
}

type SearchInput struct {
	Prefix   string   // Search by key prefix.
	Name     string   // Search by service name.
	Version  string   // Search by service version.
	Metadata Metadata // Filter by metadata if there are multiple result.
}

type Service interface {
	// GetName returns the name of the service.
	// The name is necessary for a service, and should be unique among services.
	GetName() string

	// GetVersion returns the version of the service.
	// It is suggested using GNU version naming like: v1.0.0, v2.0.1, v2.1.0-rc.
	// A service can have multiple versions deployed at once.
	// If no version set in service, the default version of service is "latest".
	GetVersion() string

	// GetKey formats and returns a unique key string for service.
	// The result key is commonly used for key-value registrar server.
	GetKey() string

	// GetValue formats and returns the value of the service.
	// The result value is commonly used for key-value registrar server.
	GetValue() string

	// GetPrefix formats and returns the key prefix string.
	// The result prefix string is commonly used in key-value registrar server
	// for service searching.
	//
	// Take etcd server for example, the prefix string is used like:
	// `etcdctl get /services/prod/hello.svc --prefix`
	GetPrefix() string

	// GetMetadata returns the Metadata map of service.
	// The Metadata is key-value pair map specifying extra attributes of a service.
	GetMetadata() Metadata

	// GetEndpoints returns the Endpoints of service.
	// The Endpoints contain multiple host/port information of service.
	GetEndpoints() Endpoints
}

type ServiceWatch func(service Service)

type Watcher interface {
	// Proceed proceeds watch in blocking way.
	// It returns all complete services that watched by `key` if any change.
	Proceed() (services []Service, err error)

	// Close closes the watcher.
	Close() error
}