impl

Documentation

Index

• type Config
• type KeyValue
• type Logger
• type Operate
• type Service
• type Status
• type System

Types

type Config

type Config struct {
	Name        string   // Required name of the service. No spaces suggested.
	DisplayName string   // Display name, spaces allowed.
	Description string   // Long description of service.
	UserName    string   // Run as username.
	Arguments   []string // Run with arguments.

	// Optional field to specify the executable for service.
	// If empty the current executable is used.
	Executable string

	// Array of service dependencies.
	// Not yet implemented on Linux or OS X.
	Dependencies []string

	// The following fields are not supported on Windows.
	WorkingDirectory string // Initial working directory.
	ChRoot           string

	// System specific options.
	//  * OS X
	//    - LaunchdConfig string ()      - Use custom launchd config
	//    - KeepAlive     bool   (true)
	//    - RunAtLoad     bool   (false)
	//    - UserService   bool   (false) - Install as a current user service.
	//    - SessionCreate bool   (false) - Create a full user session.
	//  * POSIX
	//    - SystemdScript string ()                 - Use custom systemd script
	//    - UpstartScript string ()                 - Use custom upstart script
	//    - SysvScript    string ()                 - Use custom sysv script
	//    - RunWait       func() (wait for SIGNAL)  - Do not install signal but wait for this function to return.
	//    - ReloadSignal  string () [USR1, ...]     - Signal to send on reaload.
	//    - PIDFile       string () [/run/prog.pid] - Location of the PID file.
	//    - LogOutput     bool   (false)            - Redirect StdErr & StdOut to files.
	Option KeyValue
}

Config provides the setup for a Service. The Name field is required.

type KeyValue

type KeyValue map[string]interface{}

KeyValue provides a list of platform specific options. See platform docs for more details.

type Logger

type Logger interface {
	Error(v ...interface{}) error
	Warning(v ...interface{}) error
	Info(v ...interface{}) error

	Errorf(format string, a ...interface{}) error
	Warningf(format string, a ...interface{}) error
	Infof(format string, a ...interface{}) error
}

Logger writes to the system log.

type Operate

type Operate interface {
	// Start provides a place to initiate the service. The service doesn't not
	// signal a completed start until after this function returns, so the
	// Start function must not take more then a few seconds at most.
	Start(s Service) error

	// Stop provides a place to clean up program execution before it is terminated.
	// It should not take more then a few seconds to execute.
	// Stop should not call os.Exit directly in the function.
	Stop(s Service) error
}

Interface represents the service interface for a program. Start runs before the hosting process is granted control and Stop runs when control is returned.

1. OS service manager executes user program.
2. User program sees it is executed from a service manager (IsInteractive is false).
3. User program calls Service.Run() which blocks.
4. Interface.Start() is called and quickly returns.
5. User program runs.
6. OS service manager signals the user program to stop.
7. Interface.Stop() is called and quickly returns. - For a successful exit, os.Exit should not be called in Interface.Stop().
8. Service.Run returns.
9. User program should quickly exit.

type Service

type Service interface {
	// Run should be called shortly after the program entry point.
	// After Interface.Stop has finished running, Run will stop blocking.
	// After Run stops blocking, the program must exit shortly after.
	Run() error

	// Start signals to the OS service manager the given service should start.
	Start() error

	// Stop signals to the OS service manager the given service should stop.
	Stop() error

	// Restart signals to the OS service manager the given service should stop then start.
	Restart() error

	// Install setups up the given service in the OS service manager. This may require
	// greater rights. Will return an error if it is already installed.
	Install() error

	// Uninstall removes the given service from the OS service manager. This may require
	// greater rights. Will return an error if the service is not present.
	Uninstall() error

	// Opens and returns a system logger. If the user program is running
	// interactively rather then as a service, the returned logger will write to
	// os.Stderr. If errs is non-nil errors will be sent on errs as well as
	// returned from Logger's functions.
	Logger(errs chan<- error) (Logger, error)

	// SystemLogger opens and returns a system logger. If errs is non-nil errors
	// will be sent on errs as well as returned from Logger's functions.
	SystemLogger(errs chan<- error) (Logger, error)

	// String displays the name of the service. The display name if present,
	// otherwise the name.
	String() string

	// Platform displays the name of the system that manages the service.
	// In most cases this will be the same as service.Platform().
	Platform() string

	// Status returns the current service status.
	Status() (Status, error)
}

Service represents a service that can be run or controlled.

type Status

type Status byte

Status represents service status as an byte value

const (
	StatusUnknown Status = iota // Status is unable to be determined due to an error or it was not installed.
	StatusRunning
	StatusStopped
)

Status of service represented as an byte

type System

type System interface {
	// String returns a description of the system.
	String() string

	// Detect returns true if the system is available to use.
	Detect() bool

	// Interactive returns false if running under the system service manager
	// and true otherwise.
	Interactive() bool

	// New creates a new service for this system.
	New(i Operate, c *Config) (Service, error)
}

System represents the service manager that is available.