ops: add new FileExists method

Prep for next patch. Also use that in one spot where we were manually
calling `stat`.

Author: jlebon

src/installer/installer.go

@@ -658,7 +658,7 @@ func (i *installer) waitForBootkube(ctx context.Context) {
 			return
 		case <-time.After(generalWaitInterval):
 			// check if bootkube is done every 5 seconds
-			if _, err := i.ops.ExecPrivilegeCommand(nil, "stat", "/opt/openshift/.bootkube.done"); err == nil {
+			if i.ops.FileExists("/opt/openshift/.bootkube.done") {
 				// in case bootkube is done log the status and return
 				i.log.Info("bootkube service completed")
 				out, _ := i.ops.ExecPrivilegeCommand(nil, "systemctl", "status", "bootkube.service")

src/installer/installer_test.go

@@ -297,7 +297,7 @@ var _ = Describe("installer HostRoleMaster role", func() {
 				}
 				waitForBootkubeSuccess := func() {
 					mockbmclient.EXPECT().UpdateHostInstallProgress(gomock.Any(), infraEnvId, hostId, models.HostStageWaitingForBootkube, "").Return(nil).Times(1)
-					mockops.EXPECT().ExecPrivilegeCommand(gomock.Any(), "stat", "/opt/openshift/.bootkube.done").Return("OK", nil).Times(1)
+					mockops.EXPECT().FileExists("/opt/openshift/.bootkube.done").Return(true).Times(1)
 				}
 				bootkubeStatusSuccess := func() {
 					mockops.EXPECT().ExecPrivilegeCommand(gomock.Any(), "systemctl", "status", "bootkube.service").Return("1", nil).Times(1)
@@ -1048,7 +1048,7 @@ var _ = Describe("installer HostRoleMaster role", func() {
 				}
 				waitForBootkubeSuccess := func() {
 					mockbmclient.EXPECT().UpdateHostInstallProgress(gomock.Any(), infraEnvId, hostId, models.HostStageWaitingForBootkube, "").Return(nil).Times(1)
-					mockops.EXPECT().ExecPrivilegeCommand(gomock.Any(), "stat", "/opt/openshift/.bootkube.done").Return("OK", nil).Times(1)
+					mockops.EXPECT().FileExists("/opt/openshift/.bootkube.done").Return(true).Times(1)
 				}
 				bootkubeStatusSuccess := func() {
 					mockops.EXPECT().ExecPrivilegeCommand(gomock.Any(), "systemctl", "status", "bootkube.service").Return("1", nil).Times(1)

src/ops/mock_ops.go

@@ -66,6 +66,7 @@ type Ops interface {
 	FormatDisk(string) error
 	CreateManifests(string, []byte) error
 	DryRebootHappened(markerPath string) bool
+	FileExists(path string) bool
 	ExecPrivilegeCommand(liveLogger io.Writer, command string, args ...string) (string, error)
 	ReadFile(filePath string) ([]byte, error)
 	GetEncapsulatedMC(ignitionPath string) (*mcfgv1.MachineConfig, error)
@@ -652,7 +653,12 @@ func (o *ops) CreateManifests(kubeconfig string, content []byte) error {
 // The dry run installer creates this file on "Reboot" (instead of actually rebooting)
 // We use this function to check whether the given node in the cluster have already rebooted
 func (o *ops) DryRebootHappened(markerPath string) bool {
-	_, err := o.ExecPrivilegeCommand(nil, "stat", markerPath)
+	return o.FileExists(markerPath)
+}
+
+// FileExists checks if a file exists
+func (o *ops) FileExists(path string) bool {
+	_, err := o.ExecPrivilegeCommand(nil, "stat", path)
 
 	return err == nil
 }