Utilisation du cron d'une image busybox au lieu de l'intégrer au programme dnsupdater

Dockerfile

@@ -4,8 +4,13 @@ COPY . .
 RUN go get .
 RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o dnsupdater .
 
-FROM scratch
+FROM busybox:glibc
 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"]
+
+RUN mkdir -p /var/spool/cron/crontabs /var/log
+COPY entry.sh /entry.sh
+RUN touch /var/log/cron.log
+WORKDIR "/"
+ENTRYPOINT ["/entry.sh"]

build.sh

@@ -1,4 +1,7 @@
 #!/bin/sh
 
 docker build --rm -t llehouerou/dnsupdater:latest .
-docker push llehouerou/dnsupdater
+rc=$?
+if [[ ${rc} == 0 ]]; then
+	docker push llehouerou/dnsupdater
+fi

entry.sh

@@ -0,0 +1,21 @@
+#!bin/sh
+echo "Starting container ..."
+
+echo "Setup check cron job with cron expression CHECK_CRON: ${CHECK_CRON}"
+echo "${CHECK_CRON} flock -n /tmp/check.lockfile /dnsupdater >> /var/log/cron.log 2>&1" > /var/spool/cron/crontabs/root
+
+cat /var/spool/cron/crontabs/root
+
+# Make sure the file exists before we start tail
+touch /var/log/cron.log
+
+# start the cron deamon
+crond
+
+echo "Container started."
+
+if [[ -n "${CHECKONSTART}" ]]; then
+	flock -n /tmp/check.lockfile /dnsupdater
+fi
+
+tail -fn0 /var/log/cron.log

go.mod

@@ -3,7 +3,6 @@ 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
-	github.com/sirupsen/logrus v1.4.2 // indirect
+	github.com/urfave/cli v1.20.0
-	github.com/urfave/cli v1.20.0 // indirect
 )

go.sum

@@ -1,13 +1,22 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 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/konsorten/go-windows-terminal-sequences v1.0.2 h1:DB17ag19krx9CFsz4o3enTrPXyIXCl+2iCXH/aMAp9s=
+github.com/konsorten/go-windows-terminal-sequences v1.0.2/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 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 v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 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=
+golang.org/x/sys v0.0.0-20190609082536-301114b31cce h1:CQakrGkKbydnUmt7cFIlmQ4lNQiqdTPt6xzXij4nYCc=
+golang.org/x/sys v0.0.0-20190609082536-301114b31cce/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

main.go

@@ -4,18 +4,13 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"github.com/robfig/cron"
 	log "github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 	"io/ioutil"
 	"net/http"
 	"net/smtp"
 	"os"
-	"os/signal"
 	"path"
-	"strconv"
-	"syscall"
-	"time"
 )
 
 type Configuration struct {
@@ -34,20 +29,14 @@ type DnsResponse struct {
 
 var (
 	configPath string
-	scheduleSpec string
 )
 
-var version = "master"
-var commit = "unknown"
-var date = "unknown"
-
 func main() {
 
 	app := cli.NewApp()
 	app.Name = "dnsupdater"
-	app.Version = version + " - " + commit + " - " + date
+	app.Version = "0.0.1"
 	app.Usage = "Automatically update dns"
-	app.Before = before
 	app.Action = start
 	app.Flags = []cli.Flag{
 
@@ -57,17 +46,6 @@ func main() {
 			Value:  "/config/conf.json",
 			EnvVar: "CONFIG_PATH",
 		},
-		cli.IntFlag{
-			Name:   "interval, i",
-			Usage:  "poll interval (in seconds)",
-			Value:  300,
-			EnvVar: "DNSUPDATER_POLL_INTERVAL",
-		},
-		cli.StringFlag{
-			Name:   "schedule, s",
-			Usage:  "the cron expression which defines when to update",
-			EnvVar: "DNSUPDATER_SCHEDULE",
-		},
 	}
 
 	if err := app.Run(os.Args); err != nil {
@@ -75,67 +53,11 @@ func main() {
 	}
 }
 
-func before(c *cli.Context) error {
+func start(c *cli.Context) {
-	if c.GlobalBool("debug") {
-		log.SetLevel(log.DebugLevel)
-	}
-
-	pollingSet := c.IsSet("interval")
-	cronSet := c.IsSet("schedule")
-
-	if pollingSet && cronSet {
-		log.Fatal("Only schedule or interval can be defined, not both.")
-	} else if cronSet {
-		scheduleSpec = c.String("schedule")
-	} else {
-		scheduleSpec = "@every " + strconv.Itoa(c.Int("interval")) + "s"
-	}
-	return nil
-}
-
-func start(c *cli.Context) error {
-	tryLockSem := make(chan bool, 1)
-	tryLockSem <- true
-
-	cr := cron.New()
-	err := cr.AddFunc(
-		scheduleSpec,
-		func() {
-			select {
-			case v := <-tryLockSem:
-				defer func() { tryLockSem <- v }()
 	if err := update(c); err != nil {
-					log.Println(err)
+		log.Errorln(err)
 		SendStatusMail(fmt.Sprintf("Error during update process : %s", err))
 	}
-			default:
-				log.Debug("Skipped another update already running.")
-			}
-
-			nextRuns := cr.Entries()
-			if len(nextRuns) > 0 {
-				log.Debug("Scheduled next run: " + nextRuns[0].Next.String())
-			}
-		})
-
-	if err != nil {
-		return err
-	}
-
-	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)
-	signal.Notify(interrupt, os.Interrupt)
-	signal.Notify(interrupt, syscall.SIGTERM)
-
-	<-interrupt
-	cr.Stop()
-	log.Info("Waiting for running update to be finished...")
-	<-tryLockSem
-	os.Exit(1)
-	return nil
 }
 
 func update(c *cli.Context) error {
@@ -151,30 +73,35 @@ func update(c *cli.Context) error {
 	configuration := Configuration{}
 	err := decoder.Decode(&configuration)
 
-	currentIp, err := GetCurrentIp(configuration)
-	if err != nil {
-		return err
-	}
 	newIp, err := GetOutboundIP()
 	if err != nil {
 		return err
 	}
 
-	if currentIp == newIp {
+	updatedDomains := ""
-		return nil
+	for _, domain := range configuration.Domains {
+		currentIp, err := GetCurrentIp(configuration, domain)
+		if err != nil {
+			return err
 		}
 
-	Info("Ip has changed %s -> %s", currentIp, newIp)
+		if currentIp == newIp {
+			continue
+		}
+
+		fmt.Printf("%s -> Ip has changed %s -> %s\n", domain, currentIp, newIp)
 
-	for _, domain := range configuration.Domains {
 		err = SetCurrentIp(newIp, domain, configuration)
 		if err != nil {
 			return err
 		}
+		updatedDomains += fmt.Sprintf("\t- %s\n", domain)
 	}
 
-	SendStatusMail(fmt.Sprintf(`Home IP has changed : %s -> %s
+	if updatedDomains != "" {
-Dns updated successfully`, currentIp, newIp))
+		SendStatusMail(fmt.Sprintf(`Home IP has changed : %s
+Dns updated successfully for domains\n%s`, newIp, updatedDomains))
+	}
 
 	return nil
 }
@@ -210,8 +137,8 @@ Subject: DnsUpdater Status
 	}
 }
 
-func GetCurrentIp(configuration Configuration) (string, error) {
+func GetCurrentIp(configuration Configuration, domain string) (string, error) {
-	url := "https://dns.api.gandi.net/api/v5/domains/lehouerou.net/records/@/A"
+	url := fmt.Sprintf("https://dns.api.gandi.net/api/v5/domains/%s/records/@/A", domain)
 
 	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {
@@ -290,7 +217,3 @@ func exists(path string) (bool, error) {
 	}
 	return true, err
 }
-
-func Info(format string, args ...interface{}) {
-	fmt.Printf("\x1b[34;1m%s\x1b[0m\n", fmt.Sprintf(format, args...))
-}