canary

type Config struct {
	Steps          []float64
	Every          time.Duration
	MaxP95Latency  time.Duration
	MaxHTTP5xxRate float64
}

type HTTPController struct {
	BaseURL      string
	ShiftPath    string
	RollbackPath string
	Token        string
	Client       *http.Client
}

type MetricsSource interface {
	Sample(context.Context) (Snapshot, error)
}

type PrometheusSource struct {
	BaseURL      string
	P95Query     string
	HTTP5xxQuery string
	Client       *http.Client
}

type Snapshot struct {
	P95Latency  time.Duration
	HTTP5xxRate float64
}

type TrafficController interface {
	Shift(context.Context, float64) error
	Rollback(context.Context) error
}

type Watcher struct {
	Metrics MetricsSource
	Traffic TrafficController
}