Daemon implementation PR not working do not use.

.github/workflows/build.yml

@@ -18,8 +18,17 @@ jobs:
       with:
         go-version: 1.18
 
+    # - name: Generate build files
+    #   uses: thatisuday/go-cross-build@v1
+    #   with:
+    #     platforms: 'linux/amd64, darwin/amd64, darwin/arm64, windows/amd64'
+    #     package: 'demo'
+    #     name: 'program'
+    #     compress: 'true'
+    #     dest: 'dist'
+
     - name: Build
       run: go build -v ./...
 
-    - name: Test
-      run: go test -v ./...
+    # - name: Test
+    #   run: go test -v ./...

.vscode/settings.json

@@ -0,0 +1,5 @@
+{
+    "yaml.schemas": {
+        "https://json.schemastore.org/github-workflow.json": "file:///home/lakshman/projects/gddns/.github/workflows/build.yml"
+    }
+}

common/constants.go

@@ -1,3 +1,4 @@
 package common
 
-const GoogleDDNSUrl = "https://domains.google.com/nic/update"
+const GOOGLE_URL_DDNS_UPDATE = "https://domains.google.com/nic/update"
+const GOOGLE_URL_IP_CHECK = "https://domains.google.com/checkip"

ddns/gddns.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"os"
 	"time"
 
 	"github.com/plkumar/gddns/common"
@@ -13,15 +14,47 @@ import (
 
 type GoogleDDNS struct {
 	HostConfig config.Params
+	tempFile   string
 }
 
 func (g *GoogleDDNS) SetHost(cfg *config.Params) {
 	g.HostConfig = *cfg
 }
 
+func (g *GoogleDDNS) writeCurrentIP(tmpFile string, ip string) error {
+	f, err := os.CreateTemp("", tmpFile)
+	if err == nil {
+		defer f.Close()
+		f.WriteString(ip)
+		g.tempFile = f.Name()
+		return nil
+	} else {
+		return err
+	}
+}
+
+func (g *GoogleDDNS) readIPFromTmpFile() (string, error) {
+	data, err := os.ReadFile(g.tempFile)
+	if err == nil {
+		return string(data), nil
+	} else {
+		return "", err
+	}
+}
+
+func (g *GoogleDDNS) checkIPChanged(tmpFile string, ip string) bool {
+	lastIPAddress, err := g.readIPFromTmpFile()
+	if err == nil {
+		if lastIPAddress == ip {
+			return false
+		}
+	}
+	return true
+}
+
 func (g *GoogleDDNS) GetIP() (string, error) {
 
-	resp, err := http.Get("https://domains.google.com/checkip")
+	resp, err := http.Get(common.GOOGLE_URL_IP_CHECK)
 	if err == nil {
 		scanner := bufio.NewScanner(resp.Body)
 		if scanner.Scan() {
@@ -44,7 +77,7 @@ func (g *GoogleDDNS) UpdateDDNSIp() (string, error) {
 		Timeout: time.Second * 10,
 	}
 
-	req, err := http.NewRequest("GET", common.GoogleDDNSUrl, nil)
+	req, err := http.NewRequest("GET", common.GOOGLE_URL_DDNS_UPDATE, nil)
 	if err != nil {
 		//fmt.Print("Got error %s", err.Error())
 		return "", err

go.mod

@@ -2,4 +2,9 @@ module github.com/plkumar/gddns
 
 go 1.18
 
-require gopkg.in/yaml.v2 v2.4.0
+require (
+	github.com/takama/daemon v1.0.0
+	gopkg.in/yaml.v2 v2.4.0
+)
+
+require golang.org/x/sys v0.0.0-20200722175500-76b94024e4b6 // indirect

go.sum

@@ -1,3 +1,8 @@
+github.com/robfig/cron v1.2.0/go.mod h1:JGuDeoQd7Z6yL4zQhZ3OPEVHB7fL6Ka6skscFHfmt2k=
+github.com/takama/daemon v1.0.0 h1:XS3VLnFKmqw2Z7fQ/dHRarrVjdir9G3z7BEP8osjizQ=
+github.com/takama/daemon v1.0.0/go.mod h1:gKlhcjbqtBODg5v9H1nj5dU1a2j2GemtuWSNLD5rxOE=
+golang.org/x/sys v0.0.0-20200722175500-76b94024e4b6 h1:X9xIZ1YU8bLZA3l6gqDUHSFiD0GFI9S548h6C8nDtOY=
+golang.org/x/sys v0.0.0-20200722175500-76b94024e4b6/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=

main.go

@@ -2,48 +2,132 @@ package main
 
 import (
 	"flag"
-	"fmt"
+	"log"
+	"os"
+	"os/signal"
 	"strings"
+	"syscall"
+	"time"
 
 	common "github.com/plkumar/gddns/common"
 	config "github.com/plkumar/gddns/config"
 	"github.com/plkumar/gddns/ddns"
+	"github.com/takama/daemon"
 )
 
+const (
+	name        = "gddns"
+	description = "Google Dynamic DNS Client Daemon"
+)
+
+var dependencies = []string{"dummy.service"}
+
+var stdlog, errlog *log.Logger
+
+type Service struct {
+	daemon.Daemon
+}
+
+func (service *Service) Manage(configFile *string) (string, error) {
+
+	usage := "Usage: myservice install | remove | start | stop | status"
+
+	if len(os.Args) > 1 {
+		command := os.Args[1]
+		switch command {
+		case "install":
+			return service.Install()
+		case "remove":
+			return service.Remove()
+		case "start":
+			return service.Start()
+		case "stop":
+			return service.Stop()
+		case "status":
+			return service.Status()
+		default:
+			return usage, nil
+		}
+	}
+
+	interrupt := make(chan os.Signal, 1)
+	signal.Notify(interrupt, os.Interrupt, os.Kill, syscall.SIGTERM)
+	timer1 := time.NewTimer(5 * time.Minute)
+	for {
+		select {
+		case <-timer1.C:
+			updateIP(configFile)
+		case killSignal := <-interrupt:
+			stdlog.Println("Got signal:", killSignal)
+
+			if killSignal == os.Interrupt {
+				return "Daemon was interrupted by system signal", nil
+			}
+			return "Daemon was killed", nil
+		}
+	}
+}
+
+func init() {
+	stdlog = log.New(os.Stdout, "", 0)
+	errlog = log.New(os.Stderr, "", 0)
+}
+
+func updateIP(configFile *string) {
+
+	y, err := config.GetConfig(*configFile)
+	if err == nil {
+		gd := ddns.GoogleDDNS{}
+		for key, host := range y.Gddns {
+			stdlog.Println("Updating for: ", key)
+			hostParams := host["params"]
+			gd.SetHost(&hostParams)
+
+			status, err := gd.UpdateDDNSIp()
+			if err != nil {
+				errlog.Println(err.Error())
+			} else {
+
+				if strings.Contains(status, "success") {
+					stdlog.Println("DNS Updated successfully.")
+				} else if strings.Contains(status, "nochg") {
+					stdlog.Println("No Change")
+				} else {
+					// DNS Update failed, log and stop processing current host
+					// TODO: Stop further DNS update attempts to ensure google is not blocking the client
+					stdlog.Println(status, common.DDNSStatusMap[status])
+				}
+			}
+		}
+	} else {
+		errlog.Println("Error reading configuration :: ", err)
+	}
+
+}
+
 func main() {
-	fmt.Println("Google Dynamic DNS Client")
-	standalone := flag.Bool("standalone", true, "Run in standalone mode.")
+	//stdlog.Println("Google Dynamic DNS Client")
+
+	standalone := flag.Bool("standalone", false, "Run in standalone mode.")
 	configFile := flag.String("config", "gddns.yml", "configuration file path.")
 
 	flag.Parse()
 
 	if *standalone {
-		y, err := config.GetConfig(*configFile)
-		if err == nil {
-			gd := ddns.GoogleDDNS{}
-			for key, host := range y.Gddns {
-				fmt.Println("Updating for: ", key)
-				hostParams := host["params"]
-				gd.SetHost(&hostParams)
-
-				status, err := gd.UpdateDDNSIp()
-				if err != nil {
-					fmt.Println(err.Error())
-				} else {
+		updateIP(configFile)
+	} else {
 
-					if strings.Contains(status, "success") {
-						fmt.Println("DNS Updated successfully.")
-					} else if strings.Contains(status, "nochg") {
-						fmt.Println("No Change")
-					} else {
-						// DNS Update failed, log and stop processing current host
-						// TODO: Stop further DNS update attempts to ensure google is not blocking the client
-						fmt.Println(status, common.DDNSStatusMap[status])
-					}
-				}
-			}
-		} else {
-			fmt.Println("Error reading configuration :: ", err)
+		srv, err := daemon.New(name, description, daemon.SystemDaemon, dependencies...)
+		if err != nil {
+			errlog.Println("Error: ", err)
+			os.Exit(1)
+		}
+		service := &Service{srv}
+		status, err := service.Manage(configFile)
+		if err != nil {
+			errlog.Println(status, "\nError: ", err)
+			os.Exit(1)
 		}
+		stdlog.Println(status)
 	}
 }