feat: Add custom help text

cmd/cli.go

@@ -1,11 +1,11 @@
 package main
 
 import (
-	"fmt"
 	"os"
 
 	"github.com/knadh/koanf"
 	"github.com/knadh/koanf/providers/posflag"
+	"github.com/sirupsen/logrus"
 	flag "github.com/spf13/pflag"
 )
 
@@ -27,10 +27,7 @@ func main() {
 	// Configure Flags
 	// Use the POSIX compliant pflag lib instead of Go's flag lib.
 	f := flag.NewFlagSet("config", flag.ContinueOnError)
-	f.Usage = func() {
-		fmt.Println(f.FlagUsages())
-		os.Exit(0)
-	}
+	f.Usage = renderCustomHelp
 	// Path to one or more config files to load into koanf along with some config params.
 	f.StringSliceP("query", "q", []string{}, "Domain name to query")
 	f.StringSliceP("type", "t", []string{}, "Type of DNS record to be queried (A, AAAA, MX etc)")
@@ -50,26 +47,32 @@ func main() {
 	// Output Options
 	f.BoolP("json", "J", false, "Set the output format as JSON")
 	f.Bool("time", false, "Display how long it took for the response to arrive")
+	f.Bool("color", true, "Show colored output")
 	f.Bool("debug", false, "Enable debug mode")
 
 	// Parse and Load Flags
 	f.Parse(os.Args[1:])
 	if err := k.Load(posflag.Provider(f, ".", k), nil); err != nil {
-		hub.Logger.Fatalf("error loading flags: %v", err)
-		fmt.Println(f.FlagUsages())
-		os.Exit(0)
+		hub.Logger.Errorf("error loading flags: %v", err)
+		f.Usage()
+		hub.Logger.Exit(2)
+	}
+	// set log level
+	if k.Bool("debug") {
+		// Set logger level
+		hub.Logger.SetLevel(logrus.DebugLevel)
+	} else {
+		hub.Logger.SetLevel(logrus.InfoLevel)
 	}
-
 	// Run the app.
-	hub.Logger.Debug("Starting doggo...")
+	hub.Logger.Debug("Starting doggo 🐶")
 
 	// Parse Query Args
 	hub.loadQueryArgs()
 
 	// Start App
 	if len(hub.QueryFlags.QNames) == 0 {
-		fmt.Println(f.FlagUsages())
-		os.Exit(0)
+		f.Usage()
 	}
 	hub.Lookup()
 

cmd/help.go

@@ -1,21 +1,42 @@
 package main
 
 import (
-	"fmt"
-	"io"
+	"html/template"
+	"os"
 )
 
-// Override Help Template
-var helpTmpl = `NAME:
-   {{.Name}}
-   {{ range $key, $value := . }}
-   <li><strong>{{ $key }}</strong>: {{ $value }}</li>
-{{ end }}
+// AppHelpTemplate is the text template to customise the Help output.
+// Uses text/template to render templates.
+var AppHelpTemplate = `NAME:
+  {{.Name}} {{.Description}}
+
+USAGE:
+  {{.Name}} [OPTIONS] [--] <arguments>
+
+VERSION:
+  {{.Version}} Built at {{.Date}}
+
+EXAMPLES:
+  doggo mrkaran.dev                            	Query a domain using defaults
+  doggo mrkaran.dev CNAME                      	Looks up for a CNAME record.
+  doggo mrkaran.dev MX @9.9.9.9                	Uses a custom DNS resolver.
+  doggo -q mrkaran.dev -t MX -n 1.1.1.1   	Using named arguments
 `
 
-func renderCustomHelp(w io.Writer, templ string, data interface{}) {
-	var helpTmplVars = map[string]string{}
-
-	helpTmplVars["Name"] = "doggo"
-	fmt.Fprintf(w, helpTmpl, helpTmplVars)
+func renderCustomHelp() {
+	helpTmplVars := map[string]string{
+		"Name":        "doggo",
+		"Description": "DNS Client for Humans",
+		"Version":     buildVersion,
+		"Date":        buildDate,
+	}
+	tmpl, err := template.New("test").Parse(AppHelpTemplate)
+	if err != nil {
+		panic(err)
+	}
+	err = tmpl.Execute(os.Stdout, helpTmplVars)
+	if err != nil {
+		panic(err)
+	}
+	os.Exit(0)
 }

cmd/hub.go

@@ -31,6 +31,7 @@ type QueryFlags struct {
 	ShowJSON         bool     `koanf:"json"`
 	UseSearchList    bool     `koanf:"search"`
 	Ndots            int      `koanf:"ndots"`
+	Color            bool     `koanf:"color"`
 }
 
 // NewHub initializes an instance of Hub which holds app wide configuration.

cmd/output.go

@@ -64,9 +64,15 @@ func (hub *Hub) outputJSON(out []Output, msgs []resolvers.Response) {
 }
 
 func (hub *Hub) outputTerminal(out []Output) {
-	green := color.New(color.FgGreen).SprintFunc()
-	blue := color.New(color.FgBlue).SprintFunc()
-	magenta := color.New(color.FgMagenta).SprintFunc()
+	green := color.New(color.FgGreen, color.Bold).SprintFunc()
+	blue := color.New(color.FgBlue, color.Bold).SprintFunc()
+	yellow := color.New(color.FgYellow, color.Bold).SprintFunc()
+	cyan := color.New(color.FgCyan, color.Bold).SprintFunc()
+	red := color.New(color.FgRed, color.Bold).SprintFunc()
+
+	if !hub.QueryFlags.Color {
+		color.NoColor = true // disables colorized output
+	}
 
 	table := tablewriter.NewWriter(os.Stdout)
 	header := []string{"Name", "Type", "Class", "TTL", "Address", "Nameserver"}
@@ -87,7 +93,24 @@ func (hub *Hub) outputTerminal(out []Output) {
 	table.SetNoWhiteSpace(true)
 
 	for _, o := range out {
-		output := []string{green(o.Name), blue(o.Type), o.Class, o.TTL, magenta(o.Address), o.Nameserver}
+		var typOut string
+		switch typ := o.Type; typ {
+		case "A":
+			typOut = blue(o.Type)
+		case "AAAA":
+			typOut = blue(o.Type)
+		case "MX":
+			typOut = cyan(o.Type)
+		case "NS":
+			typOut = cyan(o.Type)
+		case "CNAME":
+			typOut = yellow(o.Type)
+		case "TXT":
+			typOut = yellow(o.Type)
+		default:
+			typOut = red(o.Type)
+		}
+		output := []string{green(o.Name), typOut, o.Class, o.TTL, o.Address, o.Nameserver}
 		// Print how long it took
 		if hub.QueryFlags.DisplayTimeTaken {
 			output = append(output, o.TimeTaken)
@@ -125,10 +148,28 @@ func collectOutput(responses []resolvers.Response) []Output {
 				addr = t.AAAA.String()
 			case *dns.CNAME:
 				addr = t.Target
+			case *dns.CAA:
+				addr = t.Tag + " " + t.Value
+			case *dns.HINFO:
+				addr = t.Cpu + " " + t.Os
+			// case *dns.LOC:
+			// 	addr = t.String()
+			case *dns.PTR:
+				addr = t.Ptr
+			case *dns.SRV:
+				addr = strconv.Itoa(int(t.Priority)) + " " +
+					strconv.Itoa(int(t.Weight)) + " " +
+					t.Target + ":" + strconv.Itoa(int(t.Port))
+			case *dns.TXT:
+				addr = t.String()
+			case *dns.NS:
+				addr = t.String()
 			case *dns.MX:
 				addr = strconv.Itoa(int(t.Preference)) + " " + t.Mx
 			case *dns.SOA:
 				addr = t.String()
+			case *dns.NAPTR:
+				addr = t.String()
 			}
 
 			h := a.Header()

cmd/parse.go

@@ -5,17 +5,9 @@ import (
 	"strings"
 
 	"github.com/miekg/dns"
-	"github.com/sirupsen/logrus"
 )
 
 func (hub *Hub) loadQueryArgs() error {
-	// set log level
-	if k.Bool("debug") {
-		// Set logger level
-		hub.Logger.SetLevel(logrus.DebugLevel)
-	} else {
-		hub.Logger.SetLevel(logrus.InfoLevel)
-	}
 
 	err := hub.loadNamedArgs()