Add feature to open the browser on ready (#27)

README.md

@@ -45,7 +45,7 @@ Forwarding from 127.0.0.1:57866 -> 8443
 Forwarding from [::1]:57866 -> 8443
 ```
 
-Open the URL and you can access the Kubernetes Dashboard with the token.
+Kauthproxy will open the browser and you can access the Kubernetes Dashboard.
 
 ### Access Kibana
 

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/golang/mock v1.3.1
 	github.com/google/wire v0.3.0
 	github.com/int128/listener v1.0.0
+	github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4
 	github.com/spf13/cobra v0.0.5
 	github.com/spf13/pflag v1.0.5
 	golang.org/x/sync v0.0.0-20190423024810-112230192c58

go.sum

@@ -122,6 +122,8 @@ github.com/onsi/gomega v1.5.0/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1Cpa
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
 github.com/peterbourgon/diskv v2.0.1+incompatible h1:UBdAOUP5p4RWqPBg048CAvpKN+vxiaj6gdUUzhl4XmI=
 github.com/peterbourgon/diskv v2.0.1+incompatible/go.mod h1:uqqh8zWWbv1HBMNONnaR/tNboyR3/BZd58JJSHlUSCU=
+github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4 h1:49lOXmGaUpV9Fz3gd7TFZY106KVlPVa5jcYD1gaQf98=
+github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4/go.mod h1:4OwLy04Bl9Ef3GJJCoec+30X3LQs/0/m4HFRt/2LUSA=
 github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v0.0.0-20151028094244-d8ed2627bdf0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=

pkg/adaptors/env/env.go

@@ -4,6 +4,7 @@ import (
 	"net"
 
 	"github.com/google/wire"
+	"github.com/pkg/browser"
 	"golang.org/x/xerrors"
 )
 
@@ -16,6 +17,7 @@ var Set = wire.NewSet(
 
 type Interface interface {
 	AllocateLocalPort() (int, error)
+	OpenBrowser(url string) error
 }
 
 type Env struct{}
@@ -33,3 +35,11 @@ func (*Env) AllocateLocalPort() (int, error) {
 	}
 	return addr.Port, nil
 }
+
+// OpenBrowser opens the default browser.
+func (*Env) OpenBrowser(url string) error {
+	if err := browser.OpenURL(url); err != nil {
+		return xerrors.Errorf("could not open the browser: %w", err)
+	}
+	return nil
+}

pkg/usecases/authproxy/auth_proxy.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"net/url"
 	"strings"
+	"sync"
 
 	"github.com/cenkalti/backoff"
 	"github.com/google/wire"
@@ -85,9 +86,10 @@ func (u *AuthProxy) Do(ctx context.Context, o Option) error {
 		TargetHost:            "localhost",
 		TargetPort:            transitPort,
 	}
+	var once sync.Once
 	b := backoff.NewExponentialBackOff()
 	if err := backoff.Retry(func() error {
-		if err := u.run(ctx, pfo, rpo); err != nil {
+		if err := u.run(ctx, pfo, rpo, &once); err != nil {
 			if xerrors.Is(err, portForwarderConnectionLostError) {
 				u.Logger.Printf("retrying: %s", err)
 				return err
@@ -105,7 +107,7 @@ func (u *AuthProxy) Do(ctx context.Context, o Option) error {
 //
 //	1. Run a port forwarder.
 //	2. When the port forwarder is ready, run a reverse proxy.
-//	3. When the reverse proxy is ready, open the browser.
+//	3. When the reverse proxy is ready, open the browser (only first time).
 //
 // When the context is canceled,
 //
@@ -115,7 +117,7 @@ func (u *AuthProxy) Do(ctx context.Context, o Option) error {
 // This never returns nil.
 // It returns an error which wraps context.Canceled if the context is canceled.
 // It returns portForwarderConnectionLostError if a connection has lost.
-func (u *AuthProxy) run(ctx context.Context, pfo portforwarder.Option, rpo reverseproxy.Option) error {
+func (u *AuthProxy) run(ctx context.Context, pfo portforwarder.Option, rpo reverseproxy.Option, once *sync.Once) error {
 	portForwarderIsReady := make(chan struct{})
 	reverseProxyIsReady := make(chan reverseproxy.Instance, 1)
 	stopPortForwarder := make(chan struct{})
@@ -163,7 +165,13 @@ func (u *AuthProxy) run(ctx context.Context, pfo portforwarder.Option, rpo rever
 		select {
 		case rp := <-reverseProxyIsReady:
 			u.Logger.V(1).Infof("the reverse proxy is ready")
-			u.Logger.Printf("Open %s", rp.URL().String())
+			rpURL := rp.URL().String()
+			u.Logger.Printf("Open %s", rpURL)
+			once.Do(func() {
+				if err := u.Env.OpenBrowser(rpURL); err != nil {
+					u.Logger.Printf("error while opening the browser: %s", err)
+				}
+			})
 			// shutdown the reverse proxy when the context is done
 			eg.Go(func() error {
 				<-ctx.Done()

pkg/usecases/authproxy/auth_proxy_test.go

@@ -106,6 +106,8 @@ func TestAuthProxy_Do(t *testing.T) {
 					return nil
 				})
 			m := newMocks(ctrl)
+			m.env.EXPECT().
+				OpenBrowser("http://localhost:8000")
 			u := &AuthProxy{
 				ReverseProxy:     reverseProxy,
 				PortForwarder:    portForwarder,
@@ -270,6 +272,8 @@ func TestAuthProxy_Do(t *testing.T) {
 				}).
 				Times(2)
 			m := newMocks(ctrl)
+			m.env.EXPECT().
+				OpenBrowser("http://localhost:8000")
 			u := &AuthProxy{
 				ReverseProxy:     reverseProxy,
 				PortForwarder:    portForwarder,
@@ -295,18 +299,18 @@ func TestAuthProxy_Do(t *testing.T) {
 		type mocks struct {
 			resolverFactory  *mock_resolver.MockFactoryInterface
 			transportFactory *mock_transport.MockFactoryInterface
-			network          *mock_env.MockInterface
+			env              *mock_env.MockInterface
 		}
 		newMocks := func(ctrl *gomock.Controller) mocks {
 			m := mocks{
 				resolverFactory:  mock_resolver.NewMockFactoryInterface(ctrl),
 				transportFactory: mock_transport.NewMockFactoryInterface(ctrl),
-				network:          mock_env.NewMockInterface(ctrl),
+				env:              mock_env.NewMockInterface(ctrl),
 			}
 			m.transportFactory.EXPECT().
 				New(&restConfig).
 				Return(&authProxyTransport, nil)
-			m.network.EXPECT().
+			m.env.EXPECT().
 				AllocateLocalPort().
 				Return(transitPort, nil)
 			mockResolver := mock_resolver.NewMockInterface(ctrl)
@@ -360,12 +364,14 @@ func TestAuthProxy_Do(t *testing.T) {
 					return nil
 				})
 			m := newMocks(ctrl)
+			m.env.EXPECT().
+				OpenBrowser("http://localhost:8000")
 			u := &AuthProxy{
 				ReverseProxy:     reverseProxy,
 				PortForwarder:    portForwarder,
 				ResolverFactory:  m.resolverFactory,
 				TransportFactory: m.transportFactory,
-				Env:              m.network,
+				Env:              m.env,
 				Logger:           mock_logger.New(t),
 			}
 			o := Option{