setup go modules

build in docker
build shell script

Dockerfile

@@ -1,19 +1,11 @@
-#
-# Alpine image to get some needed data
-#
-FROM alpine:latest as alpine
-RUN apk add --no-cache \
-    ca-certificates \
-    tzdata
+FROM golang as builder
+WORKDIR /tmp/dnsupdater
+COPY . .
+RUN go get .
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o dnsupdater .
 
-#
-# Image
-#
 FROM scratch
-
-# copy files from other containers
-COPY --from=alpine /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
-COPY --from=alpine /usr/share/zoneinfo /usr/share/zoneinfo
-
-COPY main /
-ENTRYPOINT ["/main"]
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
+COPY --from=builder /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=builder /tmp/dnsupdater/dnsupdater .
+ENTRYPOINT ["/dnsupdater"]

build.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+docker build --rm -t llehouerou/dnsupdater:latest .
+docker push llehouerou/dnsupdater

go.mod

@@ -0,0 +1,9 @@
+module gogs.lehouerou.net/Laurent/dnsupdater
+
+go 1.12
+
+require (
+	github.com/robfig/cron v1.1.0 // indirect
+	github.com/sirupsen/logrus v1.4.2 // indirect
+	github.com/urfave/cli v1.20.0 // indirect
+)

go.sum

@@ -0,0 +1,13 @@
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/robfig/cron v1.1.0 h1:jk4/Hud3TTdcrJgUOBgsqrZBarcxl6ADIjSC2iniwLY=
+github.com/robfig/cron v1.1.0/go.mod h1:JGuDeoQd7Z6yL4zQhZ3OPEVHB7fL6Ka6skscFHfmt2k=
+github.com/sirupsen/logrus v1.4.2 h1:SPIRibHv4MatM3XXNO2BJeFLZwZ2LvZgfQ5+UNI2im4=
+github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
+github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/urfave/cli v1.20.0 h1:fDqGv3UG/4jbVl/QkFwEdddtEDjh/5Ov6X+0B/3bPaw=
+github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

main.go

@@ -97,8 +97,8 @@ func start(c *cli.Context) error {
 	tryLockSem := make(chan bool, 1)
 	tryLockSem <- true
 
-	cron := cron.New()
-	err := cron.AddFunc(
+	cr := cron.New()
+	err := cr.AddFunc(
 		scheduleSpec,
 		func() {
 			select {
@@ -112,7 +112,7 @@ func start(c *cli.Context) error {
 				log.Debug("Skipped another update already running.")
 			}
 
-			nextRuns := cron.Entries()
+			nextRuns := cr.Entries()
 			if len(nextRuns) > 0 {
 				log.Debug("Scheduled next run: " + nextRuns[0].Next.String())
 			}
@@ -122,8 +122,8 @@ func start(c *cli.Context) error {
 		return err
 	}
 
-	log.Info("First run: " + cron.Entries()[0].Schedule.Next(time.Now()).String())
-	cron.Start()
+	log.Info("First run: " + cr.Entries()[0].Schedule.Next(time.Now()).String())
+	cr.Start()
 
 	// Graceful shut-down on SIGINT/SIGTERM
 	interrupt := make(chan os.Signal, 1)
@@ -131,7 +131,7 @@ func start(c *cli.Context) error {
 	signal.Notify(interrupt, syscall.SIGTERM)
 
 	<-interrupt
-	cron.Stop()
+	cr.Stop()
 	log.Info("Waiting for running update to be finished...")
 	<-tryLockSem
 	os.Exit(1)
@@ -167,7 +167,10 @@ func update(c *cli.Context) error {
 	Info("Ip has changed %s -> %s", currentIp, newIp)
 
 	for _, domain := range configuration.Domains {
-		SetCurrentIp(newIp, domain, configuration)
+		err = SetCurrentIp(newIp, domain, configuration)
+		if err != nil {
+			return err
+		}
 	}
 
 	SendStatusMail(fmt.Sprintf(`Home IP has changed : %s -> %s
@@ -211,6 +214,9 @@ func GetCurrentIp(configuration Configuration) (string, error) {
 	url := "https://dns.api.gandi.net/api/v5/domains/lehouerou.net/records/@/A"
 
 	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return "", err
+	}
 	req.Header.Set("X-Api-Key", configuration.GandiKey)
 	client := &http.Client{}
 	resp, err := client.Do(req)
@@ -236,6 +242,9 @@ func SetCurrentIp(newip string, domain string, configuration Configuration) erro
 	fmt.Println("json:", str)
 	var jsonStr = []byte(str)
 	req, err := http.NewRequest("PUT", url, bytes.NewBuffer(jsonStr))
+	if err != nil {
+		return err
+	}
 	req.Header.Set("X-Api-Key", configuration.GandiKey)
 	req.Header.Set("Content-Type", "application/json")