Split Wizard up into testable components (#122)

* create internal wizard prompt package

* refactor fileExists function by removing if statement and replacing it with equivalent return statement

* refactor each generator into own flow for wizard

* Introduce prompter interface and implementation. Will be useful when it comes to writing tests as we can implement a test prompter that returns set values. The default implementation of the prompter requires an interactice stdin session

cmd/wizard.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/kubeshop/kusk/spec"
 	"github.com/kubeshop/kusk/wizard"
+	"github.com/kubeshop/kusk/wizard/prompt"
 )
 
 func init() {
@@ -28,7 +29,7 @@ func init() {
 				log.Fatal(err)
 			}
 
-			wizard.Start(apiSpecPath, apiSpec)
+			wizard.Start(apiSpecPath, apiSpec, prompt.New())
 		},
 	}
 

wizard/flow/ambassador.go

@@ -0,0 +1,65 @@
+package flow
+
+import (
+	"fmt"
+
+	"github.com/kubeshop/kusk/generators/ambassador"
+	"github.com/kubeshop/kusk/options"
+)
+
+type ambassadorFlow struct {
+	baseFlow
+}
+
+func (a ambassadorFlow) Start() (Response, error) {
+	var basePathSuggestions []string
+	for _, server := range a.apiSpec.Servers {
+		basePathSuggestions = append(basePathSuggestions, server.URL)
+	}
+
+	basePath := a.prompt.SelectOneOf("Base path prefix", basePathSuggestions, true)
+	trimPrefix := a.prompt.InputNonEmpty("Prefix to trim from the URL (rewrite)", basePath)
+
+	separateMappings := false
+
+	if basePath != "" {
+		separateMappings = a.prompt.Confirm("Generate mapping for each endpoint separately?")
+	}
+
+	opts := &options.Options{
+		Namespace: a.targetNamespace,
+		Service: options.ServiceOptions{
+			Namespace: a.targetNamespace,
+			Name:      a.targetService,
+		},
+		Path: options.PathOptions{
+			Base:       basePath,
+			TrimPrefix: trimPrefix,
+			Split:      separateMappings,
+		},
+	}
+
+	cmd := fmt.Sprintf("kusk ambassador -i %s ", a.apiSpecPath)
+	cmd = cmd + fmt.Sprintf("--namespace=%s ", a.targetNamespace)
+	cmd = cmd + fmt.Sprintf("--service.namespace=%s ", a.targetNamespace)
+	cmd = cmd + fmt.Sprintf("--service.name=%s ", a.targetService)
+	cmd = cmd + fmt.Sprintf("--path.base=%s ", basePath)
+	if trimPrefix != "" {
+		cmd = cmd + fmt.Sprintf("--path.trim_prefix=%s ", trimPrefix)
+	}
+	if separateMappings {
+		cmd = cmd + fmt.Sprintf("--path.split ")
+	}
+
+	var ag ambassador.Generator
+
+	mappings, err := ag.Generate(opts, a.apiSpec)
+	if err != nil {
+		return Response{}, fmt.Errorf("Failed to generate mappings: %s\n", err)
+	}
+
+	return Response{
+		EquivalentCmd: cmd,
+		Manifests:     mappings,
+	}, nil
+}

wizard/flow/flow.go

@@ -0,0 +1,62 @@
+package flow
+
+import (
+	"fmt"
+
+	"github.com/getkin/kin-openapi/openapi3"
+
+	"github.com/kubeshop/kusk/wizard/prompt"
+)
+
+type Interface interface {
+	Start() (Response, error)
+}
+
+type Response struct {
+	EquivalentCmd string
+	Manifests     string
+}
+
+// Flows "inherit" from this
+type baseFlow struct {
+	apiSpecPath     string
+	apiSpec         *openapi3.T
+	targetNamespace string
+	targetService   string
+
+	prompt prompt.Prompter
+}
+
+type Args struct {
+	Service string
+
+	ApiSpecPath     string
+	ApiSpec         *openapi3.T
+	TargetNamespace string
+	TargetService   string
+
+	Prompt prompt.Prompter
+}
+
+// New returns a new flow based on the args.Service
+// returns an error if the service isn't supported by a flow
+func New(args *Args) (Interface, error) {
+	baseFlow := baseFlow{
+		apiSpecPath:     args.ApiSpecPath,
+		apiSpec:         args.ApiSpec,
+		targetNamespace: args.TargetNamespace,
+		targetService:   args.TargetService,
+		prompt:          args.Prompt,
+	}
+
+	switch args.Service {
+	case "ambassador":
+		return ambassadorFlow{baseFlow}, nil
+	case "linkerd":
+		return linkerdFlow{baseFlow}, nil
+	case "nginx-ingress":
+		return nginxIngressFlow{baseFlow}, nil
+	default:
+		return nil, fmt.Errorf("unsupported service: %s\n", args.Service)
+	}
+}

wizard/flow/linkerd.go

@@ -0,0 +1,45 @@
+package flow
+
+import (
+	"fmt"
+
+	"github.com/kubeshop/kusk/generators/linkerd"
+	"github.com/kubeshop/kusk/options"
+)
+
+type linkerdFlow struct {
+	baseFlow
+}
+
+func (l linkerdFlow) Start() (Response, error) {
+	clusterDomain := l.prompt.InputNonEmpty("Cluster domain", "cluster.local")
+
+	opts := &options.Options{
+		Namespace: l.targetNamespace,
+		Service: options.ServiceOptions{
+			Namespace: l.targetNamespace,
+			Name:      l.targetService,
+		},
+		Cluster: options.ClusterOptions{
+			ClusterDomain: clusterDomain,
+		},
+	}
+
+	cmd := fmt.Sprintf("kusk linkerd -i %s ", l.apiSpecPath)
+	cmd = cmd + fmt.Sprintf("--namespace=%s ", l.targetNamespace)
+	cmd = cmd + fmt.Sprintf("--service.namespace=%s ", l.targetNamespace)
+	cmd = cmd + fmt.Sprintf("--service.name=%s ", l.targetService)
+	cmd = cmd + fmt.Sprintf("--cluster.cluster_domain=%s ", clusterDomain)
+
+	var ld linkerd.Generator
+
+	serviceProfiles, err := ld.Generate(opts, l.apiSpec)
+	if err != nil {
+		return Response{}, fmt.Errorf("failed to generate linkerd service profiles: %s\n", err)
+	}
+
+	return Response{
+		EquivalentCmd: cmd,
+		Manifests:     serviceProfiles,
+	}, nil
+}

wizard/flow/nginx_ingress.go

@@ -0,0 +1,67 @@
+package flow
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/kubeshop/kusk/generators/nginx_ingress"
+	"github.com/kubeshop/kusk/options"
+)
+
+type nginxIngressFlow struct {
+	baseFlow
+}
+
+func (n nginxIngressFlow) Start() (Response, error) {
+	var basePathSuggestions []string
+	for _, server := range n.apiSpec.Servers {
+		basePathSuggestions = append(basePathSuggestions, server.URL)
+	}
+
+	basePath := n.prompt.SelectOneOf("Base path prefix", basePathSuggestions, true)
+	trimPrefix := n.prompt.Input("Prefix to trim from the URL (rewrite)", "")
+
+	separateMappings := false
+	if basePath != "" {
+		separateMappings = n.prompt.Confirm("Generate ingress resource for each endpoint separately?")
+	}
+
+	opts := &options.Options{
+		Namespace: n.targetNamespace,
+		Service: options.ServiceOptions{
+			Namespace: n.targetNamespace,
+			Name:      n.targetService,
+		},
+		Path: options.PathOptions{
+			Base:       basePath,
+			TrimPrefix: trimPrefix,
+			Split:      separateMappings,
+		},
+	}
+
+	var sb strings.Builder
+	sb.WriteString(fmt.Sprintf("kusk ambassador -i %s ", n.apiSpecPath))
+	sb.WriteString(fmt.Sprintf("--namespace=%s ", n.targetNamespace))
+	sb.WriteString(fmt.Sprintf("--service.namespace=%s ", n.targetNamespace))
+	sb.WriteString(fmt.Sprintf("--service.name=%s ", n.targetService))
+	sb.WriteString(fmt.Sprintf("--path.base=%s ", basePath))
+
+	if trimPrefix != "" {
+		sb.WriteString(fmt.Sprintf("--path.trim_prefix=%s ", trimPrefix))
+	}
+
+	if separateMappings {
+		sb.WriteString("--path.split ")
+	}
+
+	var ingressGenerator nginx_ingress.Generator
+	ingresses, err := ingressGenerator.Generate(opts, n.apiSpec)
+	if err != nil {
+		return Response{}, fmt.Errorf("Failed to generate ingresses: %s\n", err)
+	}
+
+	return Response{
+		EquivalentCmd: sb.String(),
+		Manifests:     ingresses,
+	}, nil
+}

wizard/prompt/prompt.go

@@ -0,0 +1,134 @@
+package prompt
+
+import (
+	"errors"
+	"os"
+	"strings"
+
+	"github.com/manifoldco/promptui"
+)
+
+type Prompter interface {
+	SelectOneOf(label string, variants []string, withAdd bool) string
+	Input(label, defaultString string) string
+	InputNonEmpty(label, defaultString string) string
+	FilePath(label, defaultPath string, shouldExist bool) string
+	Confirm(question string) bool
+}
+
+type prompter struct{}
+
+func New() Prompter {
+	return prompter{}
+}
+
+func (pr prompter) SelectOneOf(label string, variants []string, withAdd bool) string {
+	if len(variants) == 0 {
+		// it's better to show a prompt
+		return pr.InputNonEmpty(label, "")
+	}
+
+	if withAdd {
+		p := promptui.SelectWithAdd{
+			Label:  label,
+			Stdout: os.Stderr,
+			Items:  variants,
+		}
+
+		_, res, _ := p.Run()
+		return res
+	}
+
+	p := promptui.Select{
+		Label:  label,
+		Stdout: os.Stderr,
+		Items:  variants,
+	}
+
+	_, res, _ := p.Run()
+	return res
+}
+
+func (_ prompter) Input(label, defaultString string) string {
+	p := promptui.Prompt{
+		Label:  label,
+		Stdout: os.Stderr,
+		Validate: func(s string) error {
+			return nil
+		},
+		Default: defaultString,
+	}
+
+	res, _ := p.Run()
+
+	return res
+}
+
+func (_ prompter) InputNonEmpty(label, defaultString string) string {
+	p := promptui.Prompt{
+		Label:  label,
+		Stdout: os.Stderr,
+		Validate: func(s string) error {
+			if strings.TrimSpace(s) == "" {
+				return errors.New("should not be empty")
+			}
+
+			return nil
+		},
+		Default: defaultString,
+	}
+
+	res, _ := p.Run()
+
+	return res
+}
+
+func (_ prompter) FilePath(label, defaultPath string, shouldExist bool) string {
+	p := promptui.Prompt{
+		Label:   label,
+		Stdout:  os.Stderr,
+		Default: defaultPath,
+		Validate: func(fp string) error {
+			if strings.TrimSpace(fp) == "" {
+				return errors.New("should not be empty")
+			}
+
+			if !shouldExist {
+				return nil
+			}
+
+			if fileExists(fp) {
+				return nil
+			}
+
+			return errors.New("should be an existing file")
+		},
+	}
+
+	res, _ := p.Run()
+
+	return res
+}
+
+func (_ prompter) Confirm(question string) bool {
+	p := promptui.Prompt{
+		Label:     question,
+		Stdout:    os.Stderr,
+		IsConfirm: true,
+	}
+
+	_, err := p.Run()
+	if err != nil {
+		if errors.Is(err, promptui.ErrAbort) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func fileExists(path string) bool {
+	// check if file exists
+	f, err := os.Stat(path)
+	return err == nil && !f.IsDir()
+}