services

type CheckFunc ¶ added in v1.2.0

type CheckFunc func() (unwell bool, meta Meta)

type Checkable ¶ added in v1.2.0

type Checkable interface {
	// Checkables should return nil if ready, or an error message otherwise.
	Ready() error
	// Checkables should return nil if healthy, or an error message otherwise.
	Healthy() error
}

Checkable should be implemented by any type requiring health checks.

type Checker ¶ added in v1.2.0

type Checker interface {
	// Register a service for health checks.
	Register(name string, service Checkable) error
	// Unregister a service.
	Unregister(name string) error
	// IsReady returns the current readiness of the system.
	// A system is considered ready if all checks are passing (no errors)
	IsReady() (ready bool, errors map[string]error)
	// IsHealthy returns the current health of the system.
	// A system is considered healthy if all checks are passing (no errors)
	IsHealthy() (healthy bool, errors map[string]error)

	Start() error
	Close() error
}

Checker provides a service which can be probed for system health.

func NewChecker() Checker

type Config ¶ added in v1.2.0

type Config interface {
	AutoPprofProfileRoot() string
	AutoPprofPollInterval() models.Duration
	AutoPprofGatherDuration() models.Duration
	AutoPprofGatherTraceDuration() models.Duration
	AutoPprofMaxProfileSize() utils.FileSize
	AutoPprofCPUProfileRate() int
	AutoPprofMemProfileRate() int
	AutoPprofBlockProfileRate() int
	AutoPprofMutexProfileFraction() int
	AutoPprofMemThreshold() utils.FileSize
	AutoPprofGoroutineThreshold() int
}

type Meta ¶ added in v1.2.0

type Meta map[string]interface{}

type Nurse ¶ added in v1.2.0

type Nurse struct {
	utils.StartStopOnce
	// contains filtered or unexported fields
}

func NewNurse(cfg Config, log logger.Logger) *Nurse

func (n *Nurse) AddCheck(reason string, checkFunc CheckFunc)

func (n *Nurse) Close() error

func (n *Nurse) GatherVitals(reason string, meta Meta)

func (n *Nurse) Start() error

type Service ¶ added in v1.2.0

type Service interface {
	// Start the service.
	Start() error
	// Close stops the Service.
	// Invariants: Usually after this call the Service cannot be started
	// again, you need to build a new Service to do so.
	Close() error

	Checkable
}

Service represents a long running service inside the Application.

Typically a Service will leverage utils.StartStopOnce to implement these calls in a safe manner.

Template ¶

Mockable Foo service with a run loop

//go:generate mockery --name Foo --output ../internal/mocks/ --case=underscore
type (
	// Expose a public interface so we can mock the service.
	Foo interface {
		service.Service

		// ...
	}

	foo struct {
		// ...

		stop chan struct{}
		done chan struct{}

		utils.StartStopOnce
	}
)

var _ Foo = (*foo)(nil)

func NewFoo() Foo {
	f := &foo{
		// ...
	}

	return f
}

func (f *foo) Start() error {
	return f.StartOnce("Foo", func() error {
		go f.run()

		return nil
	})
}

func (f *foo) Close() error {
	return f.StopOnce("Foo", func() error {
		// trigger goroutine cleanup
		close(f.stop)
		// wait for cleanup to complete
		<-f.done
		return nil
	})
}

func (f *foo) run() {
	// signal cleanup completion
	defer close(f.done)

	for {
		select {
		// ...
		case <-f.stop:
			// stop the routine
			return
		}
	}

}

type State ¶ added in v1.2.0

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

type Status ¶ added in v1.2.0

type Status string

const (
	StatusPassing Status = "passing"
	StatusFailing Status = "failing"
)