Documentation ¶
Overview ¶
Package service provides a simple way to create a system service. Currently supports Windows, Linux/(systemd | Upstart | SysV), and OSX/Launchd.
Windows controls services by setting up callbacks that is non-trivial. This is very different then other systems. This package provides the same API despite the substantial differences. It also can be used to detect how a program is called, from an interactive terminal or from a service manager.
Examples in the example/ folder.
package main import ( "log" "github.com/kardianos/service" ) var logger service.Logger type program struct{} func (p *program) Start(s service.Service) error { // Start should not block. Do the actual work async. go p.run() return nil } func (p *program) run() { // Do work here } func (p *program) Stop(s service.Service) error { // Stop should not block. Return with a few seconds. return nil } func main() { svcConfig := &service.Config{ Name: "GoServiceTest", DisplayName: "Go Service Test", Description: "This is a test Go service.", } prg := &program{} s, err := service.New(prg, svcConfig) if err != nil { log.Fatal(err) } logger, err = s.Logger(nil) if err != nil { log.Fatal(err) } err = s.Run() if err != nil { logger.Error(err) } }
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrNameFieldRequired is returned when Config.Name is empty. ErrNameFieldRequired = errors.New("Config.Name field is required.") // ErrNoServiceSystemDetected is returned when no system was detected. ErrNoServiceSystemDetected = errors.New("No service system detected.") // ErrNotInstalled is returned when the service is not installed ErrNotInstalled = errors.New("the service is not installed") )
var ConsoleLogger = consoleLogger{}
ConsoleLogger logs to the std err.
var ControlAction = [5]string{"start", "stop", "restart", "install", "uninstall"}
ControlAction list valid string texts to use in Control.
Functions ¶
func ChooseSystem ¶
func ChooseSystem(a ...System)
ChooseSystem chooses a system from the given system services. SystemServices are considered in the order they are suggested. Calling this may change what Interactive and Platform return.
func Interactive ¶
func Interactive() bool
Interactive returns false if running under the OS service manager and true otherwise.
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 fully implemented on Linux or OS X: // 1. Support linux-systemd dependencies, just put each full line as the // element of the string array, such as // "After=network.target syslog.target" // "Requires=syslog.target" // Note, such lines will be directly appended into the [Unit] of // the generated service config file, will not check their correctness. Dependencies []string // The following fields are not supported on Windows. WorkingDirectory string // Initial working directory. ChRoot string Option KeyValue }
Config provides the setup for a Service. The Name field is required.
type Interface ¶
type Interface interface { // Start provides a place to initiate the service. The service doesn't // 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.
- OS service manager executes user program.
- User program sees it is executed from a service manager (IsInteractive is false).
- User program calls Service.Run() which blocks.
- Interface.Start() is called and quickly returns.
- User program runs.
- OS service manager signals the user program to stop.
- Interface.Stop() is called and quickly returns. - For a successful exit, os.Exit should not be called in Interface.Stop().
- Service.Run returns.
- User program should quickly exit.
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 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 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 Interface, c *Config) (Service, error) }
System represents the service manager that is available.
func AvailableSystems ¶
func AvailableSystems() []System
AvailableSystems returns the list of system services considered when choosing the system service.
func ChosenSystem ¶
func ChosenSystem() System
ChosenSystem returns the system that service will use.
Source Files ¶
Directories ¶
Path | Synopsis |
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example
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logging
Simple service that only works by printing a log message every few seconds.
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Simple service that only works by printing a log message every few seconds. |
runner
Simple service that only works by printing a log message every few seconds.
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Simple service that only works by printing a log message every few seconds. |
simple
simple does nothing except block while running the service.
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simple does nothing except block while running the service. |
stopPause
simple does nothing except block while running the service.
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simple does nothing except block while running the service. |