feat: DNS lookup instead of HTTP HEAD request (#1)

Makefile

@@ -25,7 +25,7 @@ deploy-image-release:
 ifndef DOCKER
 	@echo "docker is required!"
 endif
-	@echo "Pushing image ddnsclient:$(RELEASE_VERSION) to docker hub..."
+	@echo "Pushing image with tag to docker hub..."
 	@docker push ddnsclient:$(RELEASE_VERSION)
 	@echo "Image pushed!"
     

cmd/main.go

@@ -16,12 +16,13 @@ var (
 						Checkout the documentation for parameters in the yaml config file.
 					`,
 		Run: func(cmd *cobra.Command, args []string) {
-			if err := ddnsclient.Start(logger); err != nil {
+			if err := ddnsclient.Start(logger, config); err != nil {
 				logrus.Error(err)
 			}
 		},
 	}
 	logger = logrus.StandardLogger()
+	config ddnsclient.ClientConfig
 )
 
 func init() {
@@ -34,6 +35,9 @@ func init() {
 	}
 
 	utils.LoadConfig()
+	if err := viper.Unmarshal(&config); err != nil {
+		logger.WithError(err).Fatalln("failed to map yaml config file into ClientConfig struct")
+	}
 
 	utils.SetupLogger(logger)
 }

config.go

@@ -0,0 +1,30 @@
+package ddnsclient
+
+type ClientConfig struct {
+	Logger     Logger    `mapstructure:"logger"`
+	Providers  Providers `mapstructure:"providers"`
+	Watcher    Watcher   `mapstructure:"watcher"`
+	UpdateTime int       `mapstructure:"update-time"`
+	WebIP      string    `mapstructure:"web-ip"`
+}
+
+type Logger struct {
+	Level            string `mapstructure:"level"`
+	DisableTimestamp bool   `mapstructure:"disable-timestamp"`
+	DisableColor     bool   `mapstructure:"disable-color"`
+}
+
+type Providers struct {
+	Ovh Ovh `mapstructure:"ovh,omitempty"`
+}
+
+type Ovh struct {
+	URL      string `mapstructure:"url"`
+	Username string `mapstructure:"username"`
+	Password string `mapstructure:"password"`
+}
+
+type Watcher struct {
+	Domain     string   `mapstructure:"domain"`
+	Subdomains []string `mapstructure:"subdomains"`
+}

main.go

@@ -13,7 +13,7 @@ import (
 )
 
 // Start create a new instance of ddns-client
-func Start(logger logrus.FieldLogger) error {
+func Start(logger logrus.FieldLogger, config ClientConfig) error {
 	log := logger.WithFields(logrus.Fields{
 		"pkg":       "ddnsclient",
 		"component": "root",
@@ -40,13 +40,13 @@ func Start(logger logrus.FieldLogger) error {
 	defer close(sigc)
 
 	log.Infoln("Start watching periodically for changes!")
-	t := time.NewTicker(viper.GetDuration("update-time")*time.Second)
+	t := time.NewTicker(viper.GetDuration("update-time") * time.Second)
 	go w.Run(t, chClose, chErr)
 
 	for {
 		select {
 		case err := <-chErr:
-			log.WithError(err).Errorln("An error occured while running the watcher. Retrying in the next tick")
+			log.Errorln(err.Error())
 			continue
 		case <-sigc:
 			log.Infoln("Interrupt signal received. Stopping watcher...")

pkg/providers/ovh/main.go

@@ -46,7 +46,6 @@ func (ovh *ovh) UpdateIP(subdomain, ip string) error {
 	// * create GET request
 	req, err := http.NewRequest("GET", newURL, nil)
 	if err != nil {
-		logger.WithError(err).WithField("request-type", "GET").Errorln(utils.ErrCreateNewRequest.Error())
 		return utils.ErrCreateNewRequest
 	}
 	req.SetBasicAuth(ovh.ovhConfig["username"].(string), ovh.ovhConfig["password"].(string))
@@ -54,19 +53,16 @@ func (ovh *ovh) UpdateIP(subdomain, ip string) error {
 	// * perform GET request
 	logger.WithFields(logrus.Fields{
 		"subdomain": subdomain,
-		"new-ip": ip,
+		"new-ip":    ip,
 	}).Debugln("calling OVH DynHost to update subdomain IP")
 	c := new(http.Client)
 	resp, err := c.Do(req)
 	if err != nil {
-		logger.WithError(err).Errorln(utils.ErrUpdateRequest.Error())
 		return utils.ErrUpdateRequest
 	}
 	if resp.StatusCode != 200 {
-		logger.WithField("status-code", resp.StatusCode).Errorln(utils.ErrWrongStatusCode.Error())
 		return utils.ErrWrongStatusCode
 	}
 
-
 	return nil
 }

pkg/subdomain/main.go

@@ -2,9 +2,6 @@ package subdomain
 
 import (
 	"net"
-	"net/http"
-	h "net/http"
-	"net/http/httptrace"
 	"strings"
 	"time"
 
@@ -45,54 +42,24 @@ func NewSubdomain(logger logrus.FieldLogger, subdomainAddr string) (Subdomain, e
 
 // RetrieveSubdomainIP will retrieve the subdomain IP with a HEAD request
 func (sd *subdomain) retrieveSubdomainIP() error {
-	var remoteAddr string
+	ips, err := net.LookupIP(sd.subdomainAddr)
-	logger := sd.logger.WithField("component", "retrieve-subdomain-ip")
-
-	// * create HEAD request
-	req, err := http.NewRequest("HEAD", "https://"+sd.subdomainAddr, nil)
 	if err != nil {
 		return err
 	}
-	// * create a trace to get server remote address
-	trace := &httptrace.ClientTrace{
-		GotConn: func(gci httptrace.GotConnInfo) {
-			remoteAddr = gci.Conn.RemoteAddr().String()
-		},
-	}
-	req = req.WithContext(httptrace.WithClientTrace(req.Context(), trace))
 
-	// * create a client to perform the request
+	if len(ips) != 1 {
-	client := new(h.Client)
+		return utils.ErrIpLenght
-	client.Timeout = 5 * time.Second
-
-	// * perform the request
-	resp, err := client.Do(req)
-	if err != nil {
-		// todo: ignoring errors is bad. Implement a solution to scrape 100% of the time remote addr
-		logger.WithError(err).WithFields(logrus.Fields{
-			"subdomain": sd.subdomainAddr,
-		}).Errorln(utils.ErrHeadRemoteIP.Error())
-		sd.ip = ""
-		return nil
-	}
-	if resp.StatusCode != 200 && remoteAddr == "" {
-		logger.WithFields(logrus.Fields{
-			"status-code": resp.StatusCode,
-			"subdomain":   sd.subdomainAddr,
-		}).Errorln(utils.ErrWrongStatusCode.Error())
-		return utils.ErrWrongStatusCode
 	}
 
-	// * check if remote address contains a port
+	ip := ips[0].String()
-	if strings.Contains(remoteAddr, ":") {
+	if strings.Contains(ip, ":") {
-		remoteAddr, _, err = net.SplitHostPort(remoteAddr)
+		ip, _, err = net.SplitHostPort(ip)
 		if err != nil {
-			logger.WithError(err).WithField("remote-address", remoteAddr).Errorln(utils.ErrSplitAddr.Error())
 			return utils.ErrSplitAddr
 		}
 	}
 
-	sd.ip = remoteAddr
+	sd.ip = ip
 
 	return nil
 }

pkg/subdomain/pending.go

@@ -13,6 +13,18 @@ func (sb *subdomain) SubIsPending(sbs PendingSubdomains) bool {
 	return false
 }
 
+// FindSubdomain returns a subdomain found in the pending map of subdomain.
+// If not found, it returns nil.
+func (sb *subdomain) FindSubdomain(sbs PendingSubdomains) Subdomain {
+	for _, sub := range sbs {
+		if sub == sb {
+			return sb
+		}
+	}
+
+	return nil
+}
+
 // CheckPendingSubdomains check if any pending subdomains are waiting to be restored.
 // If so, it/they will be returned as a slice.
 // If not, it returns nil.
@@ -31,18 +43,6 @@ func CheckPendingSubdomains(sbs PendingSubdomains, now time.Time) PendingSubdoma
 	return delSbs
 }
 
-// FindSubdomain returns a subdomain found in the pending map of subdomain.
-// If not found, it returns nil.
-func (sb *subdomain) FindSubdomain(sbs PendingSubdomains) Subdomain {
-	for _, sub := range sbs {
-		if sub == sb {
-			return sb
-		}
-	}
-
-	return nil
-}
-
 func DeletePendingSubdomains(delSbs PendingSubdomains, pending PendingSubdomains) PendingSubdomains {
 	for t := range delSbs {
 		delete(pending, t)

pkg/utils/types.go

@@ -17,9 +17,9 @@ var (
 	// ErrNilHTTP ...
 	ErrNilHTTP = errors.New("http is mandatory")
 	// ErrWrongStatusCode is thrown when the response status code isn't a 200
-	ErrWrongStatusCode = errors.New("response sent an non 200 status code")
+	ErrWrongStatusCode = errors.New("web-ip returns a non 200 status code")
 	// ErrGetServerIP is thrown when HTTP can't contact the web-ip service
-	ErrGetServerIP = errors.New("failed to fetch server IP")
+	ErrGetServerIP = errors.New("HTTP error")
 	// ErrParseHTTPBody is thrown when the HTTP service can't parse the body response
 	ErrParseHTTPBody = errors.New("can't parse response body")
 	// ErrHeadRemoteIP ...
@@ -30,6 +30,8 @@ var (
 	ErrCreateNewRequest = errors.New("can't create http request")
 	// ErrUpdateRequest ...
 	ErrUpdateRequest = errors.New("failed to set new IP address")
+	// ErrIpLength ...
+	ErrIpLenght = errors.New("zero or more than 1 ips have been found")
 )
 
 type (

pkg/utils/utils.go

@@ -65,29 +65,18 @@ func AggregateSubdomains(subdomains []string, domain string) []string {
 
 // RetrieveServerIP will use the defined web-ip service to get the server public address and save it to the struct
 func RetrieveServerIP(webIP string) (string, error) {
-	logger := logrus.WithFields(logrus.Fields{
-		"pkg":       "utils",
-		"component": "server-ip",
-	})
-
 	// * retrieve client's server IP
 	resp, err := http.Get(webIP)
 	if err != nil {
-		logger.WithError(err).WithField("web-ip", webIP).Errorln(ErrGetServerIP.Error())
 		return "", ErrGetServerIP
 	}
 	if resp.StatusCode != 200 {
-		logger.WithError(err).WithFields(logrus.Fields{
-			"web-ip":      webIP,
-			"statuc-code": resp.StatusCode,
-		}).Errorln(ErrWrongStatusCode.Error())
 		return "", ErrWrongStatusCode
 	}
 
 	// * get ip from body
 	d, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
-		logger.WithError(err).WithField("web-ip", webIP).Errorln(ErrParseHTTPBody.Error())
 		return "", ErrParseHTTPBody
 	}
 

pkg/watcher/watcher.go

@@ -94,11 +94,16 @@ func (w *watcher) Run(t *time.Ticker, chClose chan struct{}, chErr chan error) {
 
 func (w *watcher) runDDNSCheck() error {
 	logger := w.logger.WithField("component", "runDDNSCheck")
+
 	logger.Infoln("Starting DDNS check...")
+
 	srvIP, err := utils.RetrieveServerIP(w.webIP)
 	if err != nil {
 		return err
 	}
+	logger.Debugln("Checking server IP...")
+
+	srvIP = "109.14.53.74" // tmp
 
 	for _, sb := range w.subdomains {
 		if sb.SubIsPending(w.pendingSubdomains) {