Implement endpoint for checking if visor update is available

pkg/hypervisor/hypervisor.go

@@ -26,6 +26,7 @@ import (
 	"github.com/SkycoinProject/skywire-mainnet/internal/skyenv"
 	"github.com/SkycoinProject/skywire-mainnet/pkg/app"
 	"github.com/SkycoinProject/skywire-mainnet/pkg/routing"
+	"github.com/SkycoinProject/skywire-mainnet/pkg/util/buildinfo"
 	"github.com/SkycoinProject/skywire-mainnet/pkg/visor"
 )
 
@@ -176,6 +177,7 @@ func (hv *Hypervisor) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 			r.Post("/visors/{pk}/restart", hv.restart())
 			r.Post("/visors/{pk}/exec", hv.exec())
 			r.Post("/visors/{pk}/update", hv.update())
+			r.Get("/visors/{pk}/update/available", hv.updateAvailable())
 		})
 	})
 
@@ -734,12 +736,42 @@ func (hv *Hypervisor) exec() http.HandlerFunc {
 
 func (hv *Hypervisor) update() http.HandlerFunc {
 	return hv.withCtx(hv.visorCtx, func(w http.ResponseWriter, r *http.Request, ctx *httpCtx) {
-		if err := ctx.RPC.Update(); err != nil {
+		updated, err := ctx.RPC.Update()
+		if err != nil {
 			httputil.WriteJSON(w, r, http.StatusInternalServerError, err)
 			return
 		}
 
-		httputil.WriteJSON(w, r, http.StatusOK, true)
+		output := struct {
+			Updated bool `json:"updated"`
+		}{updated}
+
+		httputil.WriteJSON(w, r, http.StatusOK, output)
+	})
+}
+
+func (hv *Hypervisor) updateAvailable() http.HandlerFunc {
+	return hv.withCtx(hv.visorCtx, func(w http.ResponseWriter, r *http.Request, ctx *httpCtx) {
+		version, err := ctx.RPC.UpdateAvailable()
+		if err != nil {
+			httputil.WriteJSON(w, r, http.StatusInternalServerError, err)
+			return
+		}
+
+		output := struct {
+			Available        bool   `json:"available"`
+			CurrentVersion   string `json:"current_version"`
+			AvailableVersion string `json:"available_version,omitempty"`
+		}{
+			Available:      version != nil,
+			CurrentVersion: buildinfo.Version(),
+		}
+
+		if version != nil {
+			output.AvailableVersion = version.String()
+		}
+
+		httputil.WriteJSON(w, r, http.StatusOK, output)
 	})
 }
 

pkg/util/updater/updater.go

@@ -71,36 +71,31 @@ func New(log *logging.Logger, restartCtx *restart.Context, appsPath string) *Upd
 
 // Update performs an update operation.
 // NOTE: Update may call os.Exit.
-func (u *Updater) Update() (err error) {
+func (u *Updater) Update() (updated bool, err error) {
 	if !atomic.CompareAndSwapInt32(&u.updating, 0, 1) {
-		return ErrAlreadyStarted
+		return false, ErrAlreadyStarted
 	}
 	defer atomic.StoreInt32(&u.updating, 0)
 
-	u.log.Infof("Looking for updates")
-
-	lastVersion, err := lastVersion()
+	latestVersion, err := u.UpdateAvailable()
 	if err != nil {
-		return fmt.Errorf("failed to get last Skywire version: %w", err)
+		return false, fmt.Errorf("failed to get last Skywire version: %w", err)
 	}
 
-	u.log.Infof("Last Skywire version: %q", lastVersion.String())
-
-	if !updateAvailable(lastVersion) {
-		u.log.Infof("You are using the latest version of Skywire")
-		return nil
+	if latestVersion == nil {
+		return false, nil
 	}
 
-	u.log.Infof("Update found, version: %q", lastVersion.String())
+	u.log.Infof("Update found, version: %q", latestVersion.String())
 
-	downloadedBinariesPath, err := u.download(lastVersion.String())
+	downloadedBinariesPath, err := u.download(latestVersion.String())
 	if err != nil {
-		return err
+		return false, err
 	}
 
 	currentBasePath := filepath.Dir(u.restartCtx.CmdPath())
 	if err := u.updateBinaries(downloadedBinariesPath, currentBasePath); err != nil {
-		return err
+		return false, err
 	}
 
 	if err := u.restartCurrentProcess(); err != nil {
@@ -109,7 +104,7 @@ func (u *Updater) Update() (err error) {
 
 		u.restore(currentVisorPath, oldVisorPath)
 
-		return err
+		return false, err
 	}
 
 	u.removeFiles(downloadedBinariesPath)
@@ -121,7 +116,28 @@ func (u *Updater) Update() (err error) {
 		}
 	}()
 
-	return nil
+	return true, nil
+}
+
+// UpdateAvailable checks if an update is available.
+// If it is, the method returns the last available version.
+// Otherwise, it returns nil.
+func (u *Updater) UpdateAvailable() (*Version, error) {
+	u.log.Infof("Looking for updates")
+
+	latestVersion, err := latestVersion()
+	if err != nil {
+		return nil, err
+	}
+
+	u.log.Infof("Last Skywire version: %q", latestVersion.String())
+
+	if !needUpdate(latestVersion) {
+		u.log.Infof("You are using the latest version of Skywire")
+		return nil, nil
+	}
+
+	return latestVersion, nil
 }
 
 func (u *Updater) exitAfterDelay(delay time.Duration) {
@@ -392,7 +408,7 @@ func archiveFilename(file, version, os, arch string) string {
 	return file + "-" + version + "-" + os + "-" + arch + archiveFormat
 }
 
-func updateAvailable(last *Version) bool {
+func needUpdate(last *Version) bool {
 	current, err := currentVersion()
 	if err != nil {
 		// Unknown versions should be updated.
@@ -402,20 +418,20 @@ func updateAvailable(last *Version) bool {
 	return last.Cmp(current) > 0
 }
 
-func lastVersion() (*Version, error) {
-	html, err := lastVersionHTML()
+func latestVersion() (*Version, error) {
+	html, err := latestVersionHTML()
 	if err != nil {
 		return nil, err
 	}
 
-	return VersionFromString(extractLastVersion(string(html)))
+	return VersionFromString(extractLatestVersion(string(html)))
 }
 
 func currentVersion() (*Version, error) {
 	return VersionFromString(buildinfo.Version())
 }
 
-func lastVersionHTML() (data []byte, err error) {
+func latestVersionHTML() (data []byte, err error) {
 	resp, err := http.Get(releaseURL)
 	if err != nil {
 		return nil, err
@@ -430,7 +446,7 @@ func lastVersionHTML() (data []byte, err error) {
 	return ioutil.ReadAll(resp.Body)
 }
 
-func extractLastVersion(buffer string) string {
+func extractLatestVersion(buffer string) string {
 	// First occurrence is the latest version.
 	idx := strings.Index(buffer, urlText)
 	if idx == -1 {

pkg/util/updater/updater_test.go

@@ -12,7 +12,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func Test_extractLastVersion(t *testing.T) {
+func Test_extractLatestVersion(t *testing.T) {
 	tests := []struct {
 		name   string
 		buffer string
@@ -32,7 +32,7 @@ func Test_extractLastVersion(t *testing.T) {
 	for _, tc := range tests {
 		tc := tc
 		t.Run(tc.name, func(t *testing.T) {
-			got := extractLastVersion(tc.buffer)
+			got := extractLatestVersion(tc.buffer)
 			assert.Equal(t, tc.want, got)
 		})
 	}

pkg/visor/rpc.go

@@ -19,6 +19,7 @@ import (
 	"github.com/SkycoinProject/skywire-mainnet/pkg/transport"
 	"github.com/SkycoinProject/skywire-mainnet/pkg/util/buildinfo"
 	"github.com/SkycoinProject/skywire-mainnet/pkg/util/rpcutil"
+	"github.com/SkycoinProject/skywire-mainnet/pkg/util/updater"
 )
 
 const (
@@ -499,8 +500,26 @@ func (r *RPC) Exec(cmd *string, out *[]byte) (err error) {
 }
 
 // Update updates visor.
-func (r *RPC) Update(_ *struct{}, _ *struct{}) (err error) {
-	defer rpcutil.LogCall(r.log, "Update", nil)(nil, &err)
+func (r *RPC) Update(_ *struct{}, updated *bool) (err error) {
+	defer rpcutil.LogCall(r.log, "Update", nil)(updated, &err)
 
-	return r.visor.Update()
+	*updated, err = r.visor.Update()
+	return
+}
+
+// UpdateAvailable checks if visor update is available.
+func (r *RPC) UpdateAvailable(_ *struct{}, version *updater.Version) (err error) {
+	defer rpcutil.LogCall(r.log, "UpdateAvailable", nil)(version, &err)
+
+	v, err := r.visor.UpdateAvailable()
+	if err != nil {
+		return err
+	}
+
+	if v == nil {
+		return nil
+	}
+
+	*version = *v
+	return nil
 }

pkg/visor/rpc_client.go

@@ -20,6 +20,7 @@ import (
 	"github.com/SkycoinProject/skywire-mainnet/pkg/snet/snettest"
 	"github.com/SkycoinProject/skywire-mainnet/pkg/transport"
 	"github.com/SkycoinProject/skywire-mainnet/pkg/util/buildinfo"
+	"github.com/SkycoinProject/skywire-mainnet/pkg/util/updater"
 )
 
 var (
@@ -61,7 +62,8 @@ type RPCClient interface {
 
 	Restart() error
 	Exec(command string) ([]byte, error)
-	Update() error
+	Update() (bool, error)
+	UpdateAvailable() (*updater.Version, error)
 }
 
 // RPCClient provides methods to call an RPC Server.
@@ -250,9 +252,25 @@ func (rc *rpcClient) Exec(command string) ([]byte, error) {
 }
 
 // Update calls Update.
-func (rc *rpcClient) Update() error {
-	err := rc.Call("Update", &struct{}{}, &struct{}{})
-	return err
+func (rc *rpcClient) Update() (bool, error) {
+	var updated bool
+	err := rc.Call("Update", &struct{}{}, &updated)
+	return updated, err
+}
+
+// UpdateAvailable calls UpdateAvailable.
+func (rc *rpcClient) UpdateAvailable() (*updater.Version, error) {
+	var version, empty updater.Version
+	err := rc.Call("UpdateAvailable", &struct{}{}, &version)
+	if err != nil {
+		return nil, err
+	}
+
+	if version == empty {
+		return nil, nil
+	}
+
+	return &version, err
 }
 
 // MockRPCClient mocks RPCClient.
@@ -614,7 +632,12 @@ func (mc *mockRPCClient) Exec(string) ([]byte, error) {
 	return []byte("mock"), nil
 }
 
-// Exec implements RPCClient.
-func (mc *mockRPCClient) Update() error {
-	return nil
+// Update implements RPCClient.
+func (mc *mockRPCClient) Update() (bool, error) {
+	return false, nil
+}
+
+// UpdateAvailable implements RPCClient.
+func (mc *mockRPCClient) UpdateAvailable() (*updater.Version, error) {
+	return nil, nil
 }

pkg/visor/visor.go

@@ -675,15 +675,28 @@ func (visor *Visor) Exec(command string) ([]byte, error) {
 	return cmd.CombinedOutput()
 }
 
-// Update checks if visor update is available.
+// Update updates visor.
+// It checks if visor update is available.
 // If it is, the method downloads a new visor versions, starts it and kills the current process.
-func (visor *Visor) Update() error {
-	if err := visor.updater.Update(); err != nil {
+func (visor *Visor) Update() (bool, error) {
+	updated, err := visor.updater.Update()
+	if err != nil {
 		visor.logger.Errorf("Failed to update visor: %v", err)
-		return err
+		return false, err
 	}
 
-	return nil
+	return updated, nil
+}
+
+// UpdateAvailable checks if visor update is available.
+func (visor *Visor) UpdateAvailable() (*updater.Version, error) {
+	version, err := visor.updater.UpdateAvailable()
+	if err != nil {
+		visor.logger.Errorf("Failed to check if visor update is available: %v", err)
+		return nil, err
+	}
+
+	return version, nil
 }
 
 func (visor *Visor) setAutoStart(appName string, autoStart bool) error {