Add basic Windows service support

consts.go

@@ -1,6 +1,8 @@
 package main
 
 const (
+	programName = "gron"
+
 	defaultConfigFileName = "gron.conf"
 
 	defaultOnSuccessMessageFmt = "Job {{.JobName}} finished."

go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/golang-sql/civil v0.0.0-20220223132316-b832511892a9 // indirect
 	github.com/golang-sql/sqlexp v0.1.0 // indirect
 	github.com/jackc/fake v0.0.0-20150926172116-812a484cc733 // indirect
+	github.com/kardianos/service v1.2.2
 	github.com/kr/pretty v0.3.0 // indirect
 	github.com/lib/pq v1.10.6 // indirect
 	github.com/pkg/errors v0.9.1 // indirect

go.sum

@@ -27,6 +27,8 @@ github.com/jackc/fake v0.0.0-20150926172116-812a484cc733 h1:vr3AYkKovP8uR8AvSGGU
 github.com/jackc/fake v0.0.0-20150926172116-812a484cc733/go.mod h1:WrMFNQdiFJ80sQsxDoMokWK1W5TQtxBFNpzWTD84ibQ=
 github.com/jackc/pgx v3.6.2+incompatible h1:2zP5OD7kiyR3xzRYMhOcXVvkDZsImVXfj+yIyTQf3/o=
 github.com/jackc/pgx v3.6.2+incompatible/go.mod h1:0ZGrqGqkRlliWnWB4zKnWtjbSWbGkVEFm4TeybAXq+I=
+github.com/kardianos/service v1.2.2 h1:ZvePhAHfvo0A7Mftk/tEzqEZ7Q4lgnR8sGz4xu1YX60=
+github.com/kardianos/service v1.2.2/go.mod h1:CIMRFEJVL+0DS1a3Nx06NaMn4Dz63Ng6O7dl0qH0zVM=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
@@ -71,6 +73,7 @@ golang.org/x/net v0.0.0-20210610132358-84b48f89b13b/go.mod h1:9nx3DQGgdP8bBQD5qx
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201015000850-e3ed0017c211/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

httpserver.go

@@ -7,7 +7,6 @@ import (
 	"io/fs"
 	"net"
 	"net/http"
-	"os"
 	"sort"
 	"time"
 
@@ -40,7 +39,7 @@ func handler(w http.ResponseWriter, r *http.Request) {
 
 	globalMutex.RLock()
 	buf := new(bytes.Buffer)
-	jobEntries := c.Entries()
+	jobEntries := kernel.c.Entries()
 
 	jobs := make(map[string][]*Job)
 	for _, jobEntry := range jobEntries {
@@ -81,7 +80,7 @@ func handleForceStart(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	jobEntries := c.Entries()
+	jobEntries := kernel.c.Entries()
 
 	for _, jobEntry := range jobEntries {
 		job := jobEntry.Job.(*Job)
@@ -108,7 +107,7 @@ func handleShutdown(w http.ResponseWriter, r *http.Request) {
 	go func() {
 		time.Sleep(time.Second)
 		log.WithField("job", "http_server").Infoln("Shutdown requested")
-		os.Exit(0)
+		_ = kernel.Stop(nil)
 	}()
 }
 
@@ -116,10 +115,10 @@ func handleReloadJobs(w http.ResponseWriter, r *http.Request) {
 	globalMutex.Lock()
 	defer globalMutex.Unlock()
 
-	c.Stop()
+	kernel.c.Stop()
 
-	for _, entry := range c.Entries() {
+	for _, entry := range kernel.c.Entries() {
-		c.Remove(entry.ID)
+		kernel.c.Remove(entry.ID)
 	}
 
 	err := initJobs()
@@ -128,7 +127,7 @@ func handleReloadJobs(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	c.Start()
+	kernel.c.Start()
 
 	http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
 }
@@ -140,7 +139,7 @@ func handleDetails(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	jobEntries := c.Entries()
+	jobEntries := kernel.c.Entries()
 
 	for _, jobEntry := range jobEntries {
 		job := jobEntry.Job.(*Job)

kernel.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"github.com/kardianos/service"
+	"github.com/robfig/cron/v3"
+	log "github.com/sirupsen/logrus"
+)
+
+type Kernel struct {
+	// windows service data
+	svcConfig *service.Config
+
+	// Other data
+	c *cron.Cron
+}
+
+func NewKernel() *Kernel {
+	svcConfig := &service.Config{
+		Name:        "gron",
+		DisplayName: "Gron Job Scheduler",
+		Description: "Gron Job Scheduler.",
+	}
+
+	kernel = &Kernel{
+		svcConfig: svcConfig,
+		c:         cron.New()}
+
+	return kernel
+}
+
+func (k *Kernel) Start(s service.Service) error {
+	go func() {
+		log.WithField("job", "core").Info("Started.")
+
+		err := initJobs()
+		if err != nil {
+			log.Fatalln(err)
+		}
+
+		kernel.c.Start()
+	}()
+
+	return nil
+}
+
+func (k *Kernel) Stop(s service.Service) error {
+	log.Info("Got stop signal.")
+
+	err := mainLogFile.Close()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return nil
+}
+
+var kernel *Kernel

main.go

@@ -3,17 +3,13 @@ package main
 import (
 	"io"
 	"os"
-	"os/signal"
 	"path/filepath"
-	"syscall"
 
 	formatter "github.com/antonfisher/nested-logrus-formatter"
-	"github.com/robfig/cron/v3"
+	"github.com/kardianos/service"
 	log "github.com/sirupsen/logrus"
 )
 
-var c *cron.Cron
-
 func init() {
 	err := initConfig()
 	if err != nil {
@@ -36,16 +32,12 @@ func init() {
 		NoColors:        true,
 		TrimMessages:    true})
 
-	multiWriter := io.MultiWriter(os.Stderr, mainLogFile)
+	log.SetOutput(io.MultiWriter(os.Stderr, mainLogFile))
-	log.SetOutput(multiWriter)
-
 	log.SetLevel(log.InfoLevel)
 
 	initTemplate()
 
 	go httpServer(config.HttpListenAddr)
-
-	c = cron.New()
 }
 
 func initJobs() error {
@@ -66,7 +58,7 @@ func initJobs() error {
 				return err
 			}
 
-			_, err = c.AddJob(job.JobConfig.Cron, job)
+			_, err = kernel.c.AddJob(job.JobConfig.Cron, job)
 			if err != nil {
 				return err
 			}
@@ -78,35 +70,30 @@ func initJobs() error {
 		return err
 	}
 
-	if len(c.Entries()) == 0 {
+	if len(kernel.c.Entries()) == 0 {
 		log.Warn("No jobs loaded.")
 	} else {
-		log.Infof("Loaded jobs count: %d", len(c.Entries()))
+		log.Infof("Loaded jobs count: %d", len(kernel.c.Entries()))
 	}
 
 	return nil
 }
 
 func main() {
-	log := log.WithField("job", "core")
+	kernel = NewKernel()
 
-	log.Info("Started.")
+	s, err := service.New(kernel, kernel.svcConfig)
-
-	err := initJobs()
-	if err != nil {
-		log.Fatalln(err)
-	}
-
-	c.Start()
-
-	intChan := make(chan os.Signal)
-	signal.Notify(intChan, syscall.SIGTERM)
-	<-intChan
-
-	log.Info("Got stop signal.")
-
-	err = mainLogFile.Close()
 	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)
+	}
 }