lb

type Config struct {
	DBurl                string          `json:"db_url"`
	Listen               string          `json:"port"`
	ZipkinURL            string          `json:"zipkin_url"`
	Nodes                []string        `json:"nodes"`
	HealthcheckInterval  int             `json:"healthcheck_interval"`
	HealthcheckEndpoint  string          `json:"healthcheck_endpoint"`
	HealthcheckUnhealthy int             `json:"healthcheck_unhealthy"`
	HealthcheckTimeout   int             `json:"healthcheck_timeout"`
	MinAPIVersion        *semver.Version `json:"min_api_version"`

	Transport *http.Transport
}

type DBStore interface {
	Add(string) error
	Delete(string) error
	List() ([]string, error)
}

type Grouper interface {
	// List returns a set of hosts that may be used to route a request
	// for a given key.
	List(key string) ([]string, error)

	// Wrap allows adding middleware to the provided http.Handler.
	Wrap(http.Handler) http.Handler
}

type KeyFunc func(req *http.Request) (string, error)

type Router interface {

	// Route will pick a node from the given set of nodes.
	Route(nodes []string, key string) (string, error)

	// InterceptResponse allows a Router to extract information from proxied
	// requests so that it might do a better job next time. InterceptResponse
	// should not modify the Response as it has already been received nor the
	// Request, having already been sent.
	InterceptResponse(req *http.Request, resp *http.Response)

	// Wrap allows adding middleware to the provided http.Handler.
	Wrap(http.Handler) http.Handler
}