resiliency

type CircuitBreaker struct {
	// MaxRequests is the number of requests allowed in the half-open state.
	MaxRequests int `json:"maxRequests,omitempty" yaml:"maxRequests,omitempty"`
	// Interval is reserved for a future sliding-window breaker. The current
	// breaker trips on a consecutive-failure threshold (see Trip), so this
	// field is parsed for compatibility but not yet applied.
	Interval string `json:"interval,omitempty" yaml:"interval,omitempty"`
	// Timeout is how long the breaker stays open before half-open.
	Timeout string `json:"timeout,omitempty" yaml:"timeout,omitempty"`
	// Trip is a predicate describing when to open. A CEL expression is reserved
	// for future use; when empty, a default consecutive-failure threshold is
	// used.
	Trip string `json:"trip,omitempty" yaml:"trip,omitempty"`
}

type CircuitBreakerState interface {
	// Execute runs req under the breaker, classifying results via acceptable
	// (nil acceptable treats any non-nil error as a failure).
	Execute(req func() error, acceptable func(error) bool) error
	// State reports the current breaker state.
	State() State
}

type EndpointPolicyNames struct {
	Timeout                 string `json:"timeout,omitempty" yaml:"timeout,omitempty"`
	Retry                   string `json:"retry,omitempty" yaml:"retry,omitempty"`
	CircuitBreaker          string `json:"circuitBreaker,omitempty" yaml:"circuitBreaker,omitempty"`
	CircuitBreakerCacheSize int    `json:"circuitBreakerCacheSize,omitempty" yaml:"circuitBreakerCacheSize,omitempty"`
}

type Policies struct {
	Timeouts        map[string]string         `json:"timeouts,omitempty" yaml:"timeouts,omitempty"`
	Retries         map[string]Retry          `json:"retries,omitempty" yaml:"retries,omitempty"`
	CircuitBreakers map[string]CircuitBreaker `json:"circuitBreakers,omitempty" yaml:"circuitBreakers,omitempty"`
}

type PolicyDefinition struct {
	Name           string
	Timeout        time.Duration
	Retry          *RetryPolicy
	CircuitBreaker CircuitBreakerState
}

type Provider interface {
	// EndpointPolicy returns the compiled policy for an app's endpoint, or nil
	// when no policy is defined for it.
	EndpointPolicy(app, endpoint string) *PolicyDefinition
	// PolicyDefined reports whether the app has any resilience configuration.
	PolicyDefined(app string) bool
}

type Resiliency struct {
	Name   string   `json:"name" yaml:"name"`
	Spec   Spec     `json:"spec" yaml:"spec"`
	Scopes []string `json:"scopes,omitempty" yaml:"scopes,omitempty"`
}

type Retry struct {
	// Policy is the backoff strategy: "constant" or "exponential".
	Policy string `json:"policy,omitempty" yaml:"policy,omitempty"`
	// Duration is the initial backoff duration, e.g. "100ms".
	Duration string `json:"duration,omitempty" yaml:"duration,omitempty"`
	// MaxInterval caps the backoff duration.
	MaxInterval string `json:"maxInterval,omitempty" yaml:"maxInterval,omitempty"`
	// MaxRetries is the number of retries after the first attempt.
	MaxRetries *int `json:"maxRetries,omitempty" yaml:"maxRetries,omitempty"`
	// Matching restricts which errors are retried by status code.
	Matching *RetryMatching `json:"matching,omitempty" yaml:"matching,omitempty"`
}

type RetryMatching struct {
	// HTTPStatusCodes is a comma/range list, e.g. "500,502-504".
	HTTPStatusCodes string `json:"httpStatusCodes,omitempty" yaml:"httpStatusCodes,omitempty"`
	// GRPCStatusCodes is a comma/range list of gRPC status codes, e.g. "14,8".
	GRPCStatusCodes string `json:"gRPCStatusCodes,omitempty" yaml:"gRPCStatusCodes,omitempty"`
}

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

type Spec struct {
	Policies Policies `json:"policies" yaml:"policies"`
	Targets  Targets  `json:"targets" yaml:"targets"`
}

type State int32

type Targets struct {
	Apps map[string]EndpointPolicyNames `json:"apps,omitempty" yaml:"apps,omitempty"`
}