init

README.md

@@ -1 +1,5 @@
-# go-avahi-cname
+# go-avahi-cname
+
+## Source of inspiration
+
+- https://gist.github.com/gdamjan/3168336

avahi/avahi.go

@@ -0,0 +1,30 @@
+package avahi
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/godbus/dbus/v5"
+)
+
+const (
+	// From Avahi Python bindings
+	DBUS_NAME             = "org.freedesktop.Avahi"
+	DBUS_INTERFACE_SERVER = DBUS_NAME + ".Server"
+	DBUS_PATH_SERVER      = "/"
+)
+
+func PublishCNAME(cname string) {
+	fmt.Println("Publishing CNAME:", cname)
+
+	fmt.Println("Connecting to session bus")
+	conn, err := dbus.ConnectSessionBus()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "Failed to connect to session bus:", err)
+		os.Exit(1)
+	}
+	defer conn.Close()
+
+	fmt.Println("Connecting to Avahi server")
+
+}

cmd/root.go

@@ -0,0 +1,115 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+// Env and params from: https://carolynvanslyck.com/blog/2020/08/sting-of-the-viper/
+// Code https://github.com/carolynvs/stingoftheviper/blob/main/main.go#L11
+
+const (
+	// The environment variable prefix of all environment variables bound to our command line flags.
+	// For example, --number is bound to AVAHI_CNAME_NUMBER.
+	envPrefix = "AVAHI_CNAME"
+)
+
+var (
+	logger  *zap.Logger
+	verbose bool
+)
+
+func init() {
+	rootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "Enables debug logging")
+
+	cobra.OnInitialize(onInitialize)
+}
+
+func onInitialize() {
+	zapOptions := []zap.Option{
+		zap.AddStacktrace(zapcore.FatalLevel),
+		zap.AddCallerSkip(1),
+	}
+	if !verbose {
+		zapOptions = append(zapOptions,
+			zap.IncreaseLevel(zap.LevelEnablerFunc(func(l zapcore.Level) bool { return l != zapcore.DebugLevel })),
+		)
+	}
+
+	var err error
+	logger, err = zap.NewDevelopment(zapOptions...)
+	if err != nil {
+		fmt.Printf("Failed to initialize logger: %v\n", err)
+		os.Exit(-1)
+	}
+}
+
+var rootCmd = &cobra.Command{
+	Use:   "go-avahi-cname",
+	Short: "Register a mDNS/DNS-SD alias name for your computer using the Avahi daemon",
+	// TODO: Write long
+	Long: ``,
+	PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
+		// You can bind cobra and viper in a few locations, but PersistencePreRunE on the root command works well
+		return initializeConfig(cmd)
+	},
+	Run: func(cmd *cobra.Command, args []string) {
+		fmt.Println(123)
+	},
+}
+
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		logger.Fatal("We bowled a googly", zap.Error(err))
+		os.Exit(-1)
+	}
+}
+
+func initializeConfig(cmd *cobra.Command) error {
+	v := viper.New()
+
+	// When we bind flags to environment variables expect that the
+	// environment variables are prefixed, e.g. a flag like --number
+	// binds to an environment variable STING_NUMBER. This helps
+	// avoid conflicts.
+	v.SetEnvPrefix(envPrefix)
+
+	// Environment variables can't have dashes in them, so bind them to their equivalent
+	// keys with underscores, e.g. --favorite-color to STING_FAVORITE_COLOR
+	v.SetEnvKeyReplacer(strings.NewReplacer("-", "_"))
+
+	// Bind to environment variables
+	// Works great for simple config names, but needs help for names
+	// like --favorite-color which we fix in the bindFlags function
+	v.AutomaticEnv()
+
+	// Bind the current command's flags to viper
+	// bindFlags(cmd, v)
+
+	return nil
+}
+
+// Bind each cobra flag to its associated viper configuration (config file and environment variable)
+// func bindFlags(cmd *cobra.Command, v *viper.Viper) {
+// 	cmd.Flags().VisitAll(func(f *pflag.Flag) {
+// 		// Determine the naming convention of the flags when represented in the config file
+// 		configName := f.Name
+// 		// If using camelCase in the config file, replace hyphens with a camelCased string.
+// 		// Since viper does case-insensitive comparisons, we don't need to bother fixing the case, and only need to remove the hyphens.
+// 		if replaceHyphenWithCamelCase {
+// 			configName = strings.ReplaceAll(f.Name, "-", "")
+// 		}
+
+// 		// Apply the viper config value to the flag when the flag is not set and viper has a value
+// 		if !f.Changed && v.IsSet(configName) {
+// 			val := v.Get(configName)
+// 			cmd.Flags().Set(f.Name, fmt.Sprintf("%v", val))
+// 		}
+// 	})
+// }

go.mod

@@ -0,0 +1,27 @@
+module github.com/grishy/go-avahi-cname
+
+go 1.20
+
+require (
+	github.com/fsnotify/fsnotify v1.6.0 // indirect
+	github.com/godbus/dbus/v5 v5.1.0 // indirect
+	github.com/hashicorp/hcl v1.0.0 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/magiconair/properties v1.8.7 // indirect
+	github.com/mitchellh/mapstructure v1.5.0 // indirect
+	github.com/pelletier/go-toml/v2 v2.0.8 // indirect
+	github.com/spf13/afero v1.9.5 // indirect
+	github.com/spf13/cast v1.5.1 // indirect
+	github.com/spf13/cobra v1.7.0 // indirect
+	github.com/spf13/jwalterweatherman v1.1.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/spf13/viper v1.16.0 // indirect
+	github.com/subosito/gotenv v1.4.2 // indirect
+	go.uber.org/atomic v1.11.0 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
+	go.uber.org/zap v1.24.0 // indirect
+	golang.org/x/sys v0.8.0 // indirect
+	golang.org/x/text v0.9.0 // indirect
+	gopkg.in/ini.v1 v1.67.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)