Task-17: Funnel errors to cobra commands

cmd/args.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"fmt"
 	"log"
 
 	"github.com/exitshell/konnect/engine"
@@ -14,14 +15,21 @@ var ArgsCmd = &cobra.Command{
 	Long:  "Print the SSH command for a host",
 	Run: func(cmd *cobra.Command, args []string) {
 		// Resolve filename from flags.
-		filename := resolveFilename(cmd)
+		filename, err := resolveFilename(cmd)
+		handleErr(err)
 
 		// Check that only one host was specified.
 		if len(args) != 1 {
 			log.Fatal("Please specify one host")
 		}
 
+		// Init engine.
+		konnect, err := engine.Init(filename)
+		handleErr(err)
+
 		// Print Host SSH command.
-		engine.Init(filename).Args(args[0])
+		hostArgs, err := konnect.Args(args[0])
+		handleErr(err)
+		fmt.Println(hostArgs)
 	},
 }

cmd/cmd.go

@@ -57,11 +57,15 @@ func init() {
 func InteractivePrompt(cmd *cobra.Command) {
 	fmt.Println("Starting interactive prompt...")
 	// Resolve filename from flags.
-	filename := resolveFilename(cmd)
+	filename, err := resolveFilename(cmd)
+	handleErr(err)
 
-	// Init Konnect engine and get host names.
-	engine := engine.Init(filename)
-	hosts := engine.GetHosts()
+	// Init engine.
+	konnect, err := engine.Init(filename)
+	handleErr(err)
+
+	// Get host names.
+	hosts := konnect.GetHosts()
 
 	// Create survey.
 	prompt := []*survey.Question{
@@ -81,12 +85,14 @@ func InteractivePrompt(cmd *cobra.Command) {
 	}{}
 
 	// Show prompt.
-	if err := survey.Ask(prompt, &answer); err != nil {
+	if err = survey.Ask(prompt, &answer); err != nil {
 		log.Fatal("No host was selected")
 	}
 
 	// Connect to host.
-	engine.Connect(answer.Hostname)
+	if err := konnect.Connect(answer.Hostname); err != nil {
+		log.Fatal(err)
+	}
 }
 
 // AddCommands - Connects subcommands to the RootCmd.

cmd/connect.go

@@ -14,14 +14,21 @@ var ConnectCmd = &cobra.Command{
 	Long:  "Connect to a host",
 	Run: func(cmd *cobra.Command, args []string) {
 		// Resolve filename from flags.
-		filename := resolveFilename(cmd)
+		filename, err := resolveFilename(cmd)
+		handleErr(err)
 
 		// Check that only one host was specified.
 		if len(args) != 1 {
 			log.Fatal("Please specify one host")
 		}
 
+		// Init engine.
+		konnect, err := engine.Init(filename)
+		handleErr(err)
+
 		// Connect to host.
-		engine.Init(filename).Connect(args[0])
+		if err := konnect.Connect(args[0]); err != nil {
+			log.Fatal(err)
+		}
 	},
 }

cmd/init.go

@@ -23,7 +23,7 @@ var InitCmd = &cobra.Command{
 			log.Fatal("Too many args. Please specify a directory")
 		}
 
-		// If specified, then use the given directory.
+		// If a diectory is specified, then use the given directory.
 		if len(args) == 1 {
 			dir = args[0]
 		}
@@ -42,6 +42,8 @@ var InitCmd = &cobra.Command{
 			log.Fatalf("File %v already exists.\n", filename)
 		}
 
-		makeDefaultConfig(filename)
+		if err := makeDefaultConfig(filename); err != nil {
+			log.Fatal(err)
+		}
 	},
 }

cmd/list.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"fmt"
 	"log"
 
 	"github.com/exitshell/konnect/engine"
@@ -9,19 +10,24 @@ import (
 
 // ListCmd - List all hosts from config file.
 var ListCmd = &cobra.Command{
-	Use:   "ls",
+	Use:   "list",
 	Short: "List all hosts",
 	Long:  "List all hosts",
 	Run: func(cmd *cobra.Command, args []string) {
 		// Resolve filename from flags.
-		filename := resolveFilename(cmd)
+		filename, err := resolveFilename(cmd)
+		handleErr(err)
 
 		// Check that only one host was specified.
 		if len(args) != 0 {
 			log.Fatal("The list subcommand does not take any arguments")
 		}
 
+		// Init engine.
+		konnect, err := engine.Init(filename)
+		handleErr(err)
+
 		// List all hosts.
-		engine.Init(filename).List()
+		fmt.Print(konnect.List())
 	},
 }

cmd/status.go

@@ -18,9 +18,12 @@ var StatusCmd = &cobra.Command{
 	Long:  "Check the status of one or more hosts",
 	Run: func(cmd *cobra.Command, args []string) {
 		// Resolve filename from flags.
-		filename := resolveFilename(cmd)
+		filename, err := resolveFilename(cmd)
+		handleErr(err)
+
 		// Init engine.
-		konnect := engine.Init(filename)
+		konnect, err := engine.Init(filename)
+		handleErr(err)
 
 		hosts := args
 
@@ -43,7 +46,9 @@ var StatusCmd = &cobra.Command{
 		hosts = removeDuplicates(hosts)
 
 		// Validate hosts.
-		konnect.CheckHosts(hosts)
+		if err := konnect.CheckHosts(hosts); err != nil {
+			log.Fatal(err)
+		}
 
 		// Check status of the resolved hosts.
 		fmt.Printf("Testing connections for %v\n\n", strings.Join(hosts, ", "))

cmd/utils_.go

@@ -15,6 +15,14 @@ import (
 	"github.com/spf13/cobra"
 )
 
+// handleErr is a function that logs Fatal
+// if the given error `err` is populated.
+func handleErr(err error) {
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
 func getDefaultConfig() string {
 	return "./konnect.yml"
 }
@@ -36,7 +44,7 @@ func removeDuplicates(elements []string) []string {
 // Resolve the config filename from cmd flags.
 // Fallback to default filename.
 // Validate that the file exists.
-func resolveFilename(cmd *cobra.Command) string {
+func resolveFilename(cmd *cobra.Command) (string, error) {
 	// Get config filename from flags.
 	filename, _ := cmd.Flags().GetString("filename")
 	wasProvided := true
@@ -59,13 +67,13 @@ func resolveFilename(cmd *cobra.Command) string {
 			// Could not find the config file that the user specified.
 			err = fmt.Errorf("Config %v does not exist", filename)
 		}
-		log.Fatal(err)
+		return "", err
 	}
 
-	return filename
+	return filename, nil
 }
 
-func makeDefaultConfig(filename string) {
+func makeDefaultConfig(filename string) error {
 	// Make default proxylist and konnect engine.
 	proxyList := map[string]*proxy.SSHProxy{
 		"app": &proxy.SSHProxy{
@@ -87,7 +95,7 @@ func makeDefaultConfig(filename string) {
 	// Marshal konnect struct to a byte slice.
 	byteSlice, err := yaml.Marshal(konnect)
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
 
 	// Make config header.
@@ -104,10 +112,12 @@ func makeDefaultConfig(filename string) {
 
 	// Write byte slice to file.
 	if err = ioutil.WriteFile(filename, data, 0644); err != nil {
-		log.Fatal(err)
+		return err
 	}
 
 	fmt.Println("Created configuration file at:")
 	c := color.New(color.FgCyan, color.Bold)
 	c.Printf("%v\n", filename)
+
+	return nil
 }

engine/api.go

@@ -2,55 +2,54 @@ package engine
 
 import (
 	"fmt"
-	"log"
 	"path/filepath"
 	"strings"
 )
 
 // Init - Create a new Konnect object.
-func Init(filename string) *Konnect {
+func Init(filename string) (*Konnect, error) {
 	filename, err := filepath.Abs(filename)
 	if err != nil {
-		log.Fatal(err)
+		return nil, err
 	}
 
 	konnect := New()
 	if err = konnect.LoadFromFile(filename); err != nil {
-		log.Fatal(err)
+		return nil, err
 	}
 
-	return konnect
+	return konnect, nil
 }
 
 // List - Show info for all SSHProxy objects.
-func (k *Konnect) List() {
+func (k *Konnect) List() string {
+	result := ""
 	hosts := k.GetHosts()
 	for _, host := range hosts {
-		fmt.Println(k.Hosts[host].Info())
+		result += fmt.Sprintln(k.Hosts[host].Info())
 	}
+	return result
 }
 
 // Args - Print SSH Args for a given host.
-func (k *Konnect) Args(host string) {
+func (k *Konnect) Args(host string) (string, error) {
 	proxy, err := k.Get(host)
 	if err != nil {
-		log.Fatal(err)
+		return "", err
 	}
 
 	argsStr := strings.Join(proxy.Args(), " ")
-	fmt.Println(argsStr)
+	return argsStr, err
 }
 
 // Connect to host.
-func (k *Konnect) Connect(host string) {
+func (k *Konnect) Connect(host string) error {
 	proxy, err := k.Get(host)
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
 
-	if err = proxy.Connect(); err != nil {
-		log.Fatal(err)
-	}
+	return proxy.Connect()
 }
 
 // Status - Check the status of one or more hosts.

engine/engine.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"io/ioutil"
-	"log"
 	"sort"
 
 	yaml "gopkg.in/yaml.v2"
@@ -41,14 +40,15 @@ func (k *Konnect) GetHosts() []string {
 }
 
 // CheckHosts - Ensure that the given host names exist.
-func (k *Konnect) CheckHosts(hosts []string) {
+func (k *Konnect) CheckHosts(hosts []string) error {
 	// If a given host does not exist
 	// in Konnect.Hosts, then throw an error.
 	for _, host := range hosts {
 		if _, ok := k.Hosts[host]; ok != true {
-			log.Fatalf("Undefined host %v", host)
+			return fmt.Errorf("Undefined host %v", host)
 		}
 	}
+	return nil
 }
 
 // LoadFromFile - Load and validate SSHProxy objects from a yaml config file.