MGMT-16843: Ensure valid hostname during install

https://issues.redhat.com/browse/MGMT-16843
Some processes during install time depend on the hostname and an
invalid hostname (e.g. 'localhost', having capital letters, etc.)
that could cause the install to fail.

Extra validation is added when checking the hostname to ensure
it is valid. A random hostname will be assigned if the current
hostname is invalid.

src/installer/installer.go

@@ -15,6 +15,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/openshift/assisted-installer/src/main/drymock"
 	"github.com/openshift/assisted-service/pkg/secretdump"
+	"github.com/openshift/assisted-service/pkg/validations"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/thoas/go-funk"
@@ -370,7 +371,7 @@ func (i *installer) startBootstrap() error {
 	   remove the work done by 30-local-dns-prepender. This will cause DNS issue in bootkube and it will fail to complete
 	   successfully
 	*/
-	err = i.checkLocalhostName()
+	err = i.checkHostname()
 	if err != nil {
 		i.log.Error(err)
 		return err
@@ -935,24 +936,24 @@ func (i *installer) createSingleNodeMasterIgnition() (string, error) {
 	return singleNodeMasterIgnitionPath, nil
 }
 
-func (i *installer) checkLocalhostName() error {
+func (i *installer) checkHostname() error {
 	if i.DryRunEnabled {
 		return nil
 	}
 
-	i.log.Infof("Start checking localhostname")
+	i.log.Infof("Start checking hostname")
 	hostname, err := i.ops.GetHostname()
 	if err != nil {
 		i.log.Errorf("Failed to get hostname from kernel, err %s157", err)
 		return err
 	}
-	if hostname != "localhost" {
-		i.log.Infof("hostname is not localhost, no need to do anything")
+
+	if err := validations.ValidateHostname(hostname); err == nil && hostname != "localhost" {
+		i.log.Infof("hostname [%s] is not localhost or invalid, no need to do anything", hostname)
 		return nil
-	}
 
 	data := fmt.Sprintf("random-hostname-%s", uuid.New().String())
-	i.log.Infof("write data into /etc/hostname")
+	i.log.Infof("Hostname [%s] is invalid, generated random hostname [%s] and writing data into /etc/hostname")
 	return i.ops.CreateRandomHostname(data)
 }
 

src/installer/installer_test.go

@@ -369,7 +369,7 @@ var _ = Describe("installer HostRoleMaster role", func() {
 								{string(models.HostStageRebooting)},
 							})
 							bootstrapSetup()
-							checkLocalHostname("not localhost", nil)
+							checkLocalHostname("notlocalhost", nil)
 							restartNetworkManager(nil)
 							prepareControllerSuccess()
 							startServicesSuccess()
@@ -463,7 +463,7 @@ var _ = Describe("installer HostRoleMaster role", func() {
 					})
 					extractIgnitionToFS("extract failure", fmt.Errorf("extract failed"))
 					bootstrapSetup()
-					checkLocalHostname("not localhost", nil)
+					checkLocalHostname("notlocalhost", nil)
 					restartNetworkManager(nil)
 					prepareControllerSuccess()
 					startServicesSuccess()
@@ -517,7 +517,7 @@ var _ = Describe("installer HostRoleMaster role", func() {
 						{string(models.HostStageWaitingForControlPlane), waitingForBootstrapToPrepare},
 					})
 					bootstrapSetup()
-					checkLocalHostname("not localhost", nil)
+					checkLocalHostname("notlocalhost", nil)
 					err := fmt.Errorf("Failed to restart NetworkManager")
 					restartNetworkManager(err)
 					//HostRoleMaster flow:
@@ -576,7 +576,7 @@ var _ = Describe("installer HostRoleMaster role", func() {
 							extractIgnitionToFS("extract failure", fmt.Errorf("extract failed"))
 
 							bootstrapSetup()
-							checkLocalHostname("not localhost", nil)
+							checkLocalHostname("notlocalhost", nil)
 							restartNetworkManager(nil)
 							prepareControllerSuccess()
 							startServicesSuccess()
@@ -1084,7 +1084,7 @@ var _ = Describe("installer HostRoleMaster role", func() {
 					// single node bootstrap flow
 					singleNodeBootstrapSetup()
 					err := fmt.Errorf("Failed to restart NetworkManager")
-					checkLocalHostname("not localhost", err)
+					checkLocalHostname("notlocalhost", err)
 					ret := installerObj.InstallNode()
 					Expect(ret).Should(Equal(err))
 				})