Implement sshs config generator from known_hosts files

cmd/generate.go

@@ -0,0 +1,148 @@
+package cmd
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"regexp"
+	"strings"
+
+	"github.com/mitchellh/go-homedir"
+	"github.com/quantumsheep/sshconfig"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+var generateCmd = &cobra.Command{
+	Use:     "generate",
+	Short:   "Generate a ssh configuration from different sources",
+	Version: rootCmd.Version,
+	Run:     runGenerate,
+}
+
+func init() {
+	flags := generateCmd.Flags()
+	flags.Bool("known-hosts", false, "Generate from known_hosts file")
+	flags.String("known-hosts-file", "~/.ssh/known_hosts", "Path of known_hosts file")
+
+	viper.SetDefault("author", "quantumsheep <[email protected]>")
+	viper.SetDefault("license", "MIT")
+}
+
+func runGenerate(cmd *cobra.Command, args []string) {
+	flags := cmd.Flags()
+
+	knownHosts := false
+
+	if enabled, e := flags.GetBool("known-hosts"); e == nil {
+		knownHosts = enabled
+	}
+
+	if !knownHosts {
+		cmd.Help()
+		os.Exit(0)
+	}
+
+	configs := make([]*KnownHostConfig, 0)
+
+	if knownHosts {
+		knownHostsFile := "~/.ssh/known_hosts"
+
+		if str, e := flags.GetString("known-hosts-file"); e == nil && str != "" {
+			knownHostsFile = str
+		}
+
+		knownHostsFile, e := homedir.Expand(knownHostsFile)
+		if e != nil {
+			log.Fatal(e)
+		}
+
+		// open file
+		bytes, e := os.ReadFile(knownHostsFile)
+		if e != nil {
+			log.Fatal(e)
+		}
+
+		data := string(bytes)
+		rx := regexp.MustCompile(`^((\[(?P<HostWithPort>.*?)\]:(?P<Port>\d+))|((?P<DomainName>.*?),(?P<IP>.*?))|(?P<Host>.*?))[ ]`)
+
+		lines := strings.Split(data, "\n")
+		for _, line := range lines {
+			if line == "" {
+				continue
+			}
+
+			config := NewKnownHostConfig()
+
+			matches := rx.FindStringSubmatch(line)
+
+			if host := matches[rx.SubexpIndex("HostWithPort")]; host != "" {
+				config.Host = host
+				config.HostName = host
+				config.Port = matches[rx.SubexpIndex("Port")]
+			} else if host := matches[rx.SubexpIndex("DomainName")]; host != "" {
+				config.Host = host
+				config.HostName = matches[rx.SubexpIndex("IP")]
+			} else if host := matches[rx.SubexpIndex("Host")]; host != "" {
+				config.Host = host
+				config.HostName = host
+			}
+
+			configs = append(configs, config)
+		}
+	}
+
+	config := strings.Join(KnownHostConfigStrings(KnownHostConfigUniques(configs)), "\n\n")
+	fmt.Println(config)
+}
+
+type KnownHostConfig struct {
+	*sshconfig.SSHHost
+
+	Host string
+	Port string
+}
+
+func NewKnownHostConfig() *KnownHostConfig {
+	return &KnownHostConfig{
+		SSHHost: &sshconfig.SSHHost{},
+		Port:    "22",
+	}
+}
+
+func (c *KnownHostConfig) String() string {
+	return "Host " + c.Host +
+		"\n\tHostname " + c.HostName +
+		"\n\tPort " + c.Port
+}
+
+func KnownHostConfigStrings(configs []*KnownHostConfig) []string {
+	list := make([]string, 0)
+
+	for _, item := range configs {
+		list = append(list, item.String())
+	}
+
+	return list
+}
+
+func KnownHostConfigUniques(configs []*KnownHostConfig) []*KnownHostConfig {
+	list := make([]*KnownHostConfig, 0)
+
+	for _, item := range configs {
+		found := false
+
+		for _, item2 := range list {
+			if item.Host == item2.Host && item.HostName == item2.HostName && item.Port == item2.Port {
+				found = true
+				break
+			}
+		}
+
+		if !found {
+			list = append(list, item)
+		}
+	}
+
+	return list
+}

cmd/root.go

@@ -41,10 +41,29 @@ var rootCmd = &cobra.Command{
 	Use:     "sshs",
 	Short:   "ssh clients manager",
 	Version: Version,
-	Run:     run,
+	Run:     runRoot,
 }
 
-func run(cmd *cobra.Command, args []string) {
+func init() {
+	flags := rootCmd.Flags()
+	flags.StringP("search", "s", "", "Host search filter")
+	flags.StringP("config", "c", "~/.ssh/config", "SSH config file")
+	flags.BoolP("proxy", "p", false, "Display full ProxyCommand")
+
+	viper.SetDefault("author", "quantumsheep <[email protected]>")
+	viper.SetDefault("license", "MIT")
+
+	rootCmd.AddCommand(generateCmd)
+}
+
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func runRoot(cmd *cobra.Command, args []string) {
 	flags := cmd.Flags()
 
 	sshConfigPath := "~/.ssh/config"
@@ -266,20 +285,3 @@ func run(cmd *cobra.Command, args []string) {
 		ui.Render(grid)
 	}
 }
-
-func Execute() {
-	if err := rootCmd.Execute(); err != nil {
-		fmt.Println(err)
-		os.Exit(1)
-	}
-}
-
-func init() {
-	flags := rootCmd.PersistentFlags()
-	flags.StringP("search", "s", "", "Host search filter")
-	flags.StringP("config", "c", "~/.ssh/config", "SSH config file")
-	flags.BoolP("proxy", "p", false, "Display full ProxyCommand")
-
-	viper.SetDefault("author", "quantumsheep <[email protected]>")
-	viper.SetDefault("license", "MIT")
-}