refactor: split on subcommands

Dockerfile

@@ -15,4 +15,5 @@ RUN go build -ldflags="-w -s" -o /go-avahi-cname
 # STAGE 2: build the container to run
 FROM scratch
 COPY --from=builder /go-avahi-cname /go-avahi-cname
+EXPOSE 5353/udp
 ENTRYPOINT ["/go-avahi-cname"]

cmd/cname.go

@@ -0,0 +1,101 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"time"
+
+	"github.com/grishy/go-avahi-cname/publisher"
+	"github.com/miekg/dns"
+	"github.com/urfave/cli/v2"
+)
+
+func formatCname(hostnameFqdn string, cnames []string) []string {
+	log.Println("Formating CNAMEs:")
+
+	for i, cname := range cnames {
+		if !dns.IsFqdn(cname) {
+			cnames[i] = dns.Fqdn(cname + "." + hostnameFqdn)
+
+			log.Printf("  > '%s' (added current FQDN)", cnames[i])
+			continue
+		}
+
+		log.Printf("  > '%s'", cname)
+	}
+
+	return cnames
+}
+
+func publishing(ctx context.Context, publisher *publisher.Publisher, ttl, interval uint32, cnames []string) {
+	resendDuration := time.Duration(interval) * time.Second
+	log.Printf("Publishing every %v and CNAME TTL=%ds.", resendDuration, ttl)
+
+	// To start publishing immediately
+	// https://github.com/golang/go/issues/17601
+	if err := publisher.PublishCNAMES(cnames, ttl); err != nil {
+		log.Fatalf("can't publish CNAMEs: %v", err)
+	}
+
+	for {
+		select {
+		case <-time.Tick(resendDuration):
+			if err := publisher.PublishCNAMES(cnames, ttl); err != nil {
+				log.Fatalf("can't publish CNAMEs: %v", err)
+			}
+		case <-ctx.Done():
+			fmt.Println()
+			log.Println("Closing publisher...")
+			if err := publisher.Close(); err != nil {
+				log.Fatalf("Can't close publisher: %v", err)
+			}
+			os.Exit(0)
+		}
+	}
+}
+
+func cnameCmd(ctx context.Context, ttl, interval uint32, cnames []string) {
+
+}
+
+func CmdCname(ctx context.Context) *cli.Command {
+	return &cli.Command{
+		Name:  "cname",
+		Usage: "anonse CNAME via Avahi",
+		Flags: []cli.Flag{
+			&cli.UintFlag{
+				Name:    "ttl",
+				Value:   600,
+				EnvVars: []string{"CNAME_TTL"},
+				Usage:   "TTL of CNAME record in seconds",
+			},
+			&cli.UintFlag{
+				Name:    "interval",
+				Value:   300,
+				EnvVars: []string{"CNAME_INTERVAL"},
+				Usage:   "Interval of sending CNAME record in seconds",
+			},
+		},
+		Action: func(cCtx *cli.Context) error {
+			ttl := uint32(cCtx.Uint("ttl"))
+			interval := uint32(cCtx.Uint("interval"))
+			cnames := cCtx.Args().Slice()
+
+			if len(cnames) == 0 {
+				log.Fatal("CNAMEs are not specified")
+			}
+
+			log.Println("Creating publisher")
+			publisher, err := publisher.NewPublisher()
+			if err != nil {
+				log.Fatalf("Can't create publisher: %v", err)
+			}
+
+			formattedCname := formatCname(publisher.Fqdn(), cnames)
+			publishing(ctx, publisher, ttl, interval, formattedCname)
+			return nil
+		},
+	}
+}

cmd/subdomain.go

@@ -0,0 +1,38 @@
+package cmd
+
+import (
+	"context"
+
+	"github.com/urfave/cli/v2"
+)
+
+func CmdSubdomain(ctx context.Context) *cli.Command {
+	return &cli.Command{
+		Name:  "subdomain",
+		Usage: "reply on all subdomains queries",
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:    "domain",
+				Value:   "",
+				EnvVars: []string{"SUBDOMAIN_DOMAIN"},
+				Usage:   "Domain name to publish",
+			},
+			&cli.StringSliceFlag{
+				Name:    "ifaces",
+				Value:   nil,
+				EnvVars: []string{"SUBDOMAIN_IFACES"},
+				Usage:   "Interface for listening and publishing",
+			},
+			&cli.BoolFlag{
+				Name:    "use-avahi",
+				Value:   true,
+				EnvVars: []string{"SUBDOMAIN_USE_AVAHI"},
+				Usage:   "Use avahi for sending CNAMEs or plain DNS",
+			},
+		},
+		Action: func(cCtx *cli.Context) error {
+
+			return nil
+		},
+	}
+}

go.mod

@@ -6,11 +6,15 @@ require (
 	github.com/godbus/dbus/v5 v5.1.0
 	github.com/holoplot/go-avahi v1.0.1
 	github.com/miekg/dns v1.1.55
+	github.com/urfave/cli/v2 v2.25.7
 )
 
 require (
+	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
+	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 // indirect
 	golang.org/x/mod v0.12.0 // indirect
-	golang.org/x/net v0.12.0 // indirect
-	golang.org/x/sys v0.10.0 // indirect
-	golang.org/x/tools v0.11.0 // indirect
+	golang.org/x/net v0.14.0 // indirect
+	golang.org/x/sys v0.11.0 // indirect
+	golang.org/x/tools v0.12.0 // indirect
 )

go.sum

@@ -1,16 +1,24 @@
+github.com/cpuguy83/go-md2man/v2 v2.0.2 h1:p1EgwI/C7NhT0JmVkwCD2ZBK8j4aeHQX2pMHHBfMQ6w=
+github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/godbus/dbus/v5 v5.1.0 h1:4KLkAxT3aOY8Li4FRJe/KvhoNFFxo0m6fNuFUO8QJUk=
 github.com/godbus/dbus/v5 v5.1.0/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/holoplot/go-avahi v1.0.1 h1:XcqR2keL4qWRnlxHD5CAOdWpLFZJ+EOUK0vEuylfvvk=
 github.com/holoplot/go-avahi v1.0.1/go.mod h1:qH5psEKb0DK+BRplMfc+RY4VMOlbf6mqfxgpMy6aP0M=
 github.com/miekg/dns v1.1.55 h1:GoQ4hpsj0nFLYe+bWiCToyrBEJXkQfOOIvFGFy0lEgo=
 github.com/miekg/dns v1.1.55/go.mod h1:uInx36IzPl7FYnDcMeVWxj9byh7DutNykX4G9Sj60FY=
+github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/urfave/cli/v2 v2.25.7 h1:VAzn5oq403l5pHjc4OhD54+XGO9cdKVL/7lDjF+iKUs=
+github.com/urfave/cli/v2 v2.25.7/go.mod h1:8qnjx1vcq5s2/wpsqoZFndg2CE5tNFyrTvS6SinrnYQ=
+github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 h1:bAn7/zixMGCfxrRTfdpNzjtPYqr8smhKouy9mxVdGPU=
+github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673/go.mod h1:N3UwUGtsrSj3ccvlPHLoLsHnpR27oXr4ZE984MbSER8=
 golang.org/x/mod v0.12.0 h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
 golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/net v0.12.0 h1:cfawfvKITfUsFCeJIHJrbSxpeu/E81khclypR0GVT50=
-golang.org/x/net v0.12.0/go.mod h1:zEVYFnQC7m/vmpQFELhcD1EWkZlX69l4oqgmer6hfKA=
+golang.org/x/net v0.14.0 h1:BONx9s002vGdD9umnlX1Po8vOZmrgH34qlHcD1MfK14=
+golang.org/x/net v0.14.0/go.mod h1:PpSgVXXLK0OxS0F31C1/tv6XNguvCrnXIDrFMspZIUI=
 golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
-golang.org/x/sys v0.10.0 h1:SqMFp9UcQJZa+pmYuAKjd9xq1f0j5rLcDIk0mj4qAsA=
-golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/tools v0.11.0 h1:EMCa6U9S2LtZXLAMoWiR/R8dAQFRqbAitmbJ2UKhoi8=
-golang.org/x/tools v0.11.0/go.mod h1:anzJrxPjNtfgiYQYirP2CPGzGLxrH2u2QBhn6Bf3qY8=
+golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
+golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/tools v0.12.0 h1:YW6HUoUmYBpwSgyaGaZq1fHjrBjX1rlpZ54T6mu2kss=
+golang.org/x/tools v0.12.0/go.mod h1:Sc0INKfu04TlqNoRA1hgpFZbhYXHPr4V5DzpSBTPqQM=

main.go

@@ -2,72 +2,28 @@ package main
 
 import (
 	"context"
-	"fmt"
 	"log"
 	"os"
 	"os/signal"
-	"time"
 
-	"github.com/grishy/go-avahi-cname/publisher"
-	"github.com/miekg/dns"
+	"github.com/grishy/go-avahi-cname/cmd"
+	"github.com/urfave/cli/v2"
 )
 
-const TTL = uint32(10 * 60) // in seconds
-
-func formatCname(hostnameFqdn string, cnames []string) []string {
-	log.Println("Formating CNAMEs:")
-
-	for i, cname := range cnames {
-		if !dns.IsFqdn(cname) {
-			cnames[i] = dns.Fqdn(cname + "." + hostnameFqdn)
-
-			log.Printf("  > '%s' (added current FQDN)", cnames[i])
-			continue
-		}
-
-		log.Printf("  > '%s'", cname)
-	}
-
-	return cnames
-}
-
-func publishing(ctx context.Context, publisher *publisher.Publisher, cnames []string) {
-	resendDuration := time.Duration(TTL/2) * time.Second
-	log.Printf("Publishing every %v and CNAME TTL=%ds.", resendDuration, TTL)
-
-	// To start publishing immediately
-	// https://github.com/golang/go/issues/17601
-	if err := publisher.PublishCNAMES(cnames, TTL); err != nil {
-		log.Fatalf("can't publish CNAMEs: %v", err)
-	}
-
-	for {
-		select {
-		case <-time.Tick(resendDuration):
-			if err := publisher.PublishCNAMES(cnames, TTL); err != nil {
-				log.Fatalf("can't publish CNAMEs: %v", err)
-			}
-		case <-ctx.Done():
-			fmt.Println()
-			log.Println("Closing publisher...")
-			if err := publisher.Close(); err != nil {
-				log.Fatalf("Can't close publisher: %v", err)
-			}
-			os.Exit(0)
-		}
-	}
-}
-
 func main() {
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
 	defer stop()
 
-	log.Println("Creating publisher")
-	publisher, err := publisher.NewPublisher()
-	if err != nil {
-		log.Fatalf("Can't create publisher: %v", err)
+	app := &cli.App{
+		Name:  "go-avahi-cname",
+		Usage: "make an explosive entrance",
+		Commands: []*cli.Command{
+			cmd.CmdCname(ctx),
+			cmd.CmdSubdomain(ctx),
+		},
 	}
 
-	cnames := formatCname(publisher.Fqdn(), os.Args[1:])
-	publishing(ctx, publisher, cnames)
+	if err := app.Run(os.Args); err != nil {
+		log.Fatal(err)
+	}
 }