services

Documentation

Overview

Package services provides mechanisms to start multiple services in the background

Index

• Constants
• Variables
• type CommandService
  • func (s CommandService) Start(ctx context.Context, ready chan<- struct{}) error
  • func (s CommandService) String() string
• type HttpService
  • func (s HttpService) Start(ctx context.Context, ready chan<- struct{}) error
  • func (s HttpService) String() string
• type ServerManager
  • func (s ServerManager) Start(ctx context.Context, ready chan<- struct{}) error
  • func (s ServerManager) String() string
• type Service
• type SupervisorService
  • func (s SupervisorService) Start(ctx context.Context, ready chan<- struct{}) error
  • func (s SupervisorService) String() string

Constants

const (
	DefaultPollInterval = 100 * time.Millisecond
)

const DefaultServiceTimeout = 5 * time.Second

Variables

var (
	ServiceTimeoutError    = errors.New("timed out waiting for service to be ready")
	SupervisorTimeoutError = errors.New("timed out waiting for services to stop")
)

Types

type CommandService

type CommandService struct {

	// Name that identifies the service.
	Name string

	// Port used to verify if the service is ready.
	HealthcheckPort int

	// Path to the service binary.
	Path string

	// Args to the service binary.
	Args []string

	// Environment variables.
	Env []string

	// Working Directory
	WorkDir string
}

CommandService encapsulates the execution of an executable via exec.Command. It assumes the executable accepts TCP connections at HealthcheckPort, which it uses to determine if it is ready or not.

func (CommandService) Start

func (s CommandService) Start(ctx context.Context, ready chan<- struct{}) error

func (CommandService) String

func (s CommandService) String() string

type HttpService

type HttpService struct {
	Name    string
	Address string
	Handler http.Handler
}

func (HttpService) Start

func (s HttpService) Start(ctx context.Context, ready chan<- struct{}) error

func (HttpService) String

func (s HttpService) String() string

type ServerManager

type ServerManager struct {
	// Name that identifies the service.
	Name string

	// Port used to verify if the service is ready.
	HealthcheckPort int

	// Path to the service binary.
	Path string

	// Args to the service binary.
	Args []string

	// Environment variables.
	Env []string

	// Bypass the log and write directly to stdout/stderr.
	BypassLog bool

	// Working Directory
	WorkDir string
}

ServerManager is a variation of CommandService used to manually stop the orphaned cartesi-machines left after server-manager exits. For more information, check https://github.com/cartesi/server-manager/issues/18

func (ServerManager) Start

func (s ServerManager) Start(ctx context.Context, ready chan<- struct{}) error

func (ServerManager) String

func (s ServerManager) String() string

type Service

type Service interface {
	fmt.Stringer

	// Starts a service and sends a message to the channel when ready
	Start(ctx context.Context, ready chan<- struct{}) error
}

type SupervisorService

type SupervisorService struct {
	// Name of the service
	Name string

	// Services to be managed
	Services []Service

	// The amount of time to wait for a service to be ready.
	// Default is 5 seconds
	ReadyTimeout time.Duration

	// The amount of time to wait for a service to exit after
	// its context is canceled. Default is 5 seconds
	StopTimeout time.Duration
}

SupervisorService is a simple implementation of a supervisor. It runs its services until the first returns a non-nil error.

func (SupervisorService) Start

func (s SupervisorService) Start(ctx context.Context, ready chan<- struct{}) error

func (SupervisorService) String

func (s SupervisorService) String() string