refactor: Move file from interfaces to authtoken package directories …

…and add comments (Azure#938)

* move interfaces.go from interfaces to authtoken/providers directory and add commenting

* Edit comments

* Rename structs, add periods to comments and update AuthToken comment

* remove pkg/interfaces to be copied from go source

* Ran goimports -w on files in pkg/authtoken/providers/ directory

* Elaborate commenting for documentation

* Reorder imports by moving fleet pkgs to the bottom

cmd/authtoken/main.go

@@ -16,15 +16,14 @@ import (
 	"go.goms.io/fleet/pkg/authtoken"
 	"go.goms.io/fleet/pkg/authtoken/providers/azure"
 	"go.goms.io/fleet/pkg/authtoken/providers/secret"
-	"go.goms.io/fleet/pkg/interfaces"
 )
 
 var (
 	configPath string
 )
 
-func parseArgs() (interfaces.AuthTokenProvider, error) {
-	var tokenProvider interfaces.AuthTokenProvider
+func parseArgs() (authtoken.Provider, error) {
+	var tokenProvider authtoken.Provider
 	rootCmd := &cobra.Command{Use: "refreshtoken", Args: cobra.NoArgs}
 	rootCmd.PersistentFlags().StringVar(&configPath, "file-path", "/config/token", "token file path")
 

docker/refresh-token.Dockerfile

@@ -12,7 +12,6 @@ RUN go mod download
 # Copy the go source
 COPY cmd/authtoken/main.go main.go
 COPY pkg/authtoken pkg/authtoken
-COPY pkg/interfaces pkg/interfaces
 
 ARG TARGETARCH
 

pkg/authtoken/interfaces.go

@@ -0,0 +1,30 @@
+/*
+Copyright (c) Microsoft Corporation.
+Licensed under the MIT license.
+*/
+package authtoken
+
+import (
+	"context"
+	"time"
+)
+
+// An AuthToken is an authentication token used to communicate with the hub API server.
+type AuthToken struct {
+	Token     string    // The authentication token string.
+	ExpiresOn time.Time // The expiration time of the token.
+}
+
+// Provider defines a method for fetching an authentication token.
+type Provider interface {
+	// FetchToken fetches an authentication token to make requests to its associated fleet's hub cluster.
+	// It returns the token for a given input context, or an error if the retrieval fails.
+	FetchToken(ctx context.Context) (AuthToken, error)
+}
+
+// Writer defines a method for writing an authentication token to a specified location.
+type Writer interface {
+	// WriteToken writes the provided authentication token to a filepath location specified in a TokenWriter.
+	// It returns an error if the writing process fails.
+	WriteToken(token AuthToken) error
+}

pkg/authtoken/providers/azure/azure_msi.go

@@ -14,7 +14,7 @@ import (
 	"k8s.io/client-go/util/retry"
 	"k8s.io/klog/v2"
 
-	"go.goms.io/fleet/pkg/interfaces"
+	"go.goms.io/fleet/pkg/authtoken"
 )
 
 const (
@@ -26,7 +26,7 @@ type AuthTokenProvider struct {
 	Scope    string
 }
 
-func New(clientID, scope string) interfaces.AuthTokenProvider {
+func New(clientID, scope string) authtoken.Provider {
 	if scope == "" {
 		scope = aksScope
 	}
@@ -37,8 +37,8 @@ func New(clientID, scope string) interfaces.AuthTokenProvider {
 }
 
 // FetchToken gets a new token to make request to the associated fleet' hub cluster.
-func (a *AuthTokenProvider) FetchToken(ctx context.Context) (interfaces.AuthToken, error) {
-	token := interfaces.AuthToken{}
+func (a *AuthTokenProvider) FetchToken(ctx context.Context) (authtoken.AuthToken, error) {
+	token := authtoken.AuthToken{}
 	opts := &azidentity.ManagedIdentityCredentialOptions{ID: azidentity.ClientID(a.ClientID)}
 
 	klog.V(2).InfoS("FetchToken", "client ID", a.ClientID)

pkg/authtoken/providers/secret/k8s_secret.go

@@ -16,7 +16,7 @@ import (
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
-	"go.goms.io/fleet/pkg/interfaces"
+	"go.goms.io/fleet/pkg/authtoken"
 )
 
 var (
@@ -29,7 +29,7 @@ type secretAuthTokenProvider struct {
 	secretNamespace string
 }
 
-func New(secretName, namespace string) (interfaces.AuthTokenProvider, error) {
+func New(secretName, namespace string) (authtoken.Provider, error) {
 	client, err := getClient()
 	if err != nil {
 		return nil, fmt.Errorf("an error occurred will creating client: %w", err)
@@ -41,9 +41,9 @@ func New(secretName, namespace string) (interfaces.AuthTokenProvider, error) {
 	}, nil
 }
 
-func (s *secretAuthTokenProvider) FetchToken(ctx context.Context) (interfaces.AuthToken, error) {
+func (s *secretAuthTokenProvider) FetchToken(ctx context.Context) (authtoken.AuthToken, error) {
 	klog.V(2).InfoS("fetching token from secret", "secret", klog.KRef(s.secretName, s.secretNamespace))
-	token := interfaces.AuthToken{}
+	token := authtoken.AuthToken{}
 	secret, err := s.fetchSecret(ctx)
 	if err != nil {
 		return token, fmt.Errorf("cannot get the secret: %w", err)

pkg/authtoken/token_refresher.go

@@ -10,22 +10,20 @@ import (
 	"time"
 
 	"k8s.io/klog/v2"
-
-	"go.goms.io/fleet/pkg/interfaces"
 )
 
-type RefreshDurationFuncType func(token interfaces.AuthToken) time.Duration
+type RefreshDurationFuncType func(token AuthToken) time.Duration
 type CreateTickerFuncType func(time.Duration) <-chan time.Time
 
 type Refresher struct {
-	provider         interfaces.AuthTokenProvider
-	writer           interfaces.AuthTokenWriter
+	provider         Provider
+	writer           Writer
 	refreshCalculate RefreshDurationFuncType
 	createTicker     CreateTickerFuncType
 }
 
-func NewAuthTokenRefresher(tokenProvider interfaces.AuthTokenProvider,
-	writer interfaces.AuthTokenWriter,
+func NewAuthTokenRefresher(tokenProvider Provider,
+	writer Writer,
 	refreshCalculate RefreshDurationFuncType,
 	createTicker CreateTickerFuncType) *Refresher {
 	return &Refresher{
@@ -37,14 +35,14 @@ func NewAuthTokenRefresher(tokenProvider interfaces.AuthTokenProvider,
 }
 
 var (
-	DefaultRefreshDurationFunc = func(token interfaces.AuthToken) time.Duration {
+	DefaultRefreshDurationFunc = func(token AuthToken) time.Duration {
 		return time.Until(token.ExpiresOn) / 2
 	}
 	DefaultCreateTicker    = time.Tick
 	DefaultRefreshDuration = time.Second * 30
 )
 
-func (at *Refresher) callFetchToken(ctx context.Context) (interfaces.AuthToken, error) {
+func (at *Refresher) callFetchToken(ctx context.Context) (AuthToken, error) {
 	klog.V(2).InfoS("FetchToken start")
 	deadline := time.Now().Add(DefaultRefreshDuration)
 	fetchTokenContext, cancel := context.WithDeadline(ctx, deadline)

pkg/authtoken/token_refresher_test.go

@@ -12,22 +12,20 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
-
-	"go.goms.io/fleet/pkg/interfaces"
 )
 
 type MockAuthTokenProvider struct {
-	Token interfaces.AuthToken
+	Token AuthToken
 }
 
-func (m MockAuthTokenProvider) FetchToken(_ context.Context) (interfaces.AuthToken, error) {
+func (m MockAuthTokenProvider) FetchToken(_ context.Context) (AuthToken, error) {
 	return m.Token, nil
 }
 
 // TestRefreshTokenOnce test to refresh/rewrite token for one time
 func TestRefreshTokenOnce(t *testing.T) {
 	provider := MockAuthTokenProvider{
-		Token: interfaces.AuthToken{
+		Token: AuthToken{
 			Token:     "test token",
 			ExpiresOn: time.Now(),
 		},
@@ -60,7 +58,7 @@ func TestRefreshTokenOnce(t *testing.T) {
 // TestRefreshToken test to refresh/rewrite token multiple times
 func TestRefreshToken(t *testing.T) {
 	provider := MockAuthTokenProvider{
-		Token: interfaces.AuthToken{
+		Token: AuthToken{
 			Token:     "test token",
 			ExpiresOn: time.Now(),
 		},
@@ -99,7 +97,7 @@ func TestRefreshToken(t *testing.T) {
 // TestRefresherCancelContext test if the func will be canceled/returned once the ctx is canceled
 func TestRefresherCancelContext(t *testing.T) {
 	provider := MockAuthTokenProvider{
-		Token: interfaces.AuthToken{
+		Token: AuthToken{
 			Token:     "test token",
 			ExpiresOn: time.Now().Add(100 * time.Millisecond),
 		},

pkg/authtoken/token_writer.go

@@ -10,8 +10,6 @@ import (
 	"os"
 
 	"k8s.io/klog/v2"
-
-	"go.goms.io/fleet/pkg/interfaces"
 )
 
 type Factory struct {
@@ -30,17 +28,17 @@ func (w Factory) Create() (io.WriteCloser, error) {
 	return wc, nil
 }
 
-type Writer struct {
+type TokenWriter struct {
 	writerFactory func() (io.WriteCloser, error)
 }
 
-func NewWriter(factory func() (io.WriteCloser, error)) interfaces.AuthTokenWriter {
-	return &Writer{
+func NewWriter(factory func() (io.WriteCloser, error)) Writer {
+	return &TokenWriter{
 		writerFactory: factory,
 	}
 }
 
-func (w *Writer) WriteToken(token interfaces.AuthToken) error {
+func (w *TokenWriter) WriteToken(token AuthToken) error {
 	writer, err := w.writerFactory()
 	if err != nil {
 		return err

pkg/authtoken/token_writer_test.go

@@ -11,8 +11,6 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
-
-	"go.goms.io/fleet/pkg/interfaces"
 )
 
 type BufferWriterFactory struct {
@@ -43,7 +41,7 @@ func (c BufferWriter) Close() error {
 }
 
 func TestWriteToken(t *testing.T) {
-	token := interfaces.AuthToken{
+	token := AuthToken{
 		Token:     "test token",
 		ExpiresOn: time.Now(),
 	}