Implement elemental-register upgrade

Signed-off-by: Andrea Mazzotti <andrea.mazzotti@suse.com>

cmd/register/main.go

@@ -74,6 +74,7 @@ func main() {
 	cmd.AddCommand(
 		newVersionCommand(),
 		newDumpDataCommand(),
+		newUpgradeCommand(),
 	)
 	if err := cmd.Execute(); err != nil {
 		log.Fatalf("FATAL: %s", err)

cmd/register/upgrade.go

@@ -0,0 +1,131 @@
+/*
+Copyright © 2022 - 2024 SUSE LLC
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+
+	"github.com/rancher/elemental-operator/pkg/elementalcli"
+	"github.com/rancher/elemental-operator/pkg/install"
+	"github.com/rancher/elemental-operator/pkg/log"
+	"github.com/spf13/cobra"
+	"github.com/twpayne/go-vfs"
+)
+
+var (
+	ErrRebooting           = errors.New("Machine needs reboot after upgrade")
+	ErrAlreadyShuttingDown = errors.New("System is already shutting down")
+)
+
+func newUpgradeCommand() *cobra.Command {
+	var hostDir string
+	var cloudConfigPath string
+	var recovery bool
+	var recoveryOnly bool
+	var debug bool
+	var system string
+	var correlationID string
+
+	cmd := &cobra.Command{
+		Use:   "upgrade",
+		Short: "Upgrades the machine",
+		RunE: func(_ *cobra.Command, _ []string) error {
+			// If the system is shutting down, return an error so we can try again on next reboot.
+			alreadyShuttingDown, err := isSystemShuttingDown()
+			if err != nil {
+				return fmt.Errorf("determining if system is running: %w", err)
+			}
+			if alreadyShuttingDown {
+				return ErrAlreadyShuttingDown
+			}
+
+			// If system is not shutting down we can proceed.
+			upgradeConfig := elementalcli.UpgradeConfig{
+				Debug:        debug,
+				Recovery:     recovery,
+				RecoveryOnly: recoveryOnly,
+				System:       system,
+				Bootloader:   true,
+			}
+			upgradeContext := install.UpgradeContext{
+				Config:          upgradeConfig,
+				HostDir:         hostDir,
+				CloudConfigPath: cloudConfigPath,
+				CorrelationID:   correlationID,
+			}
+
+			log.Infof("Upgrade context: %+v", upgradeContext)
+
+			installer := install.NewInstaller(vfs.OSFS, nil, nil)
+
+			needsReboot, err := installer.UpgradeElemental(upgradeContext)
+			// If the upgrade could not be applied or verified,
+			// then this command will fail but the machine will not reboot.
+			if err != nil {
+				return fmt.Errorf("upgrading machine: %w", err)
+			}
+			// If the machine needs a reboot after an upgrade has been applied,
+			// so that consumers can try again after reboot to validate the upgrade has been applied successfully.
+			if needsReboot {
+				log.Infof("Rebooting machine after %s upgrade", correlationID)
+				reboot()
+				return ErrRebooting
+			}
+			// Upgrade has been applied successfully, nothing to do.
+			log.Infof("Upgrade %s applied successfully", correlationID)
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVar(&hostDir, "host-dir", "/host", "The machine root directory where to apply the upgrade")
+	cmd.Flags().StringVar(&cloudConfigPath, "cloud-config", "/run/data/cloud-config", "The path of a cloud-config file to install on the machine during upgrade")
+	cmd.Flags().StringVar(&system, "system", "dir:/", "The system image uri or filesystem location to upgrade to")
+	cmd.Flags().StringVar(&correlationID, "correlation-id", "", "A correlationID to label the upgrade snapshot with")
+	cmd.Flags().BoolVar(&recovery, "recovery", false, "Upgrades the recovery partition together with the system")
+	cmd.Flags().BoolVar(&recoveryOnly, "recovery-only", false, "Upgrades the recovery partition only")
+	cmd.Flags().BoolVar(&debug, "debug", true, "Prints debug logs when performing upgrade")
+	return cmd
+}
+
+func isSystemShuttingDown() (bool, error) {
+	cmd := exec.Command("nsenter")
+	cmd.Stdin = os.Stdin
+	cmd.Stderr = os.Stderr
+	cmd.Args = []string{"-i", "-m", "-t", "1", "--", "systemctl is-system-running"}
+	output, err := cmd.Output()
+	if err != nil {
+		return false, fmt.Errorf("running: systemctl is-system-running: %w", err)
+	}
+	if string(output) == "stopping" {
+		return true, nil
+	}
+	return false, nil
+}
+
+func reboot() {
+	cmd := exec.Command("nsenter")
+	cmd.Stdin = os.Stdin
+	cmd.Stderr = os.Stderr
+	cmd.Stdout = os.Stdout
+	cmd.Args = []string{"-i", "-m", "-t", "1", "--", "reboot"}
+	if err := cmd.Run(); err != nil {
+		log.Errorf("Could not reboot: %s", err)
+	}
+}

pkg/elementalcli/elementalcli.go

@@ -22,16 +22,46 @@ import (
 	"os/exec"
 	"strconv"
 	"strings"
+	"time"
 
 	elementalv1 "github.com/rancher/elemental-operator/api/v1beta1"
 	"github.com/rancher/elemental-operator/pkg/log"
+	"gopkg.in/yaml.v3"
 )
 
-const TempCloudInitDir = "/tmp/elemental/cloud-init"
+const (
+	TempCloudInitDir   = "/tmp/elemental/cloud-init"
+	UpgradeLockFile    = "/run/elemental/upgrade.lock"
+	UpgradeLockTimeout = 60 * time.Second
+)
+
+type UpgradeConfig struct {
+	Debug          bool
+	Recovery       bool
+	RecoveryOnly   bool
+	System         string
+	Bootloader     bool
+	SnapshotLabels map[string]string
+}
+
+type State struct {
+	StatePartition PartitionState `yaml:"state,omitempty"`
+}
+
+type PartitionState struct {
+	Snapshots map[int]*Snapshot `yaml:"snapshots,omitempty"`
+}
+
+type Snapshot struct {
+	Active bool              `yaml:"active,omitempty"`
+	Labels map[string]string `yaml:"labels,omitempty"`
+}
 
 type Runner interface {
 	Install(elementalv1.Install) error
 	Reset(elementalv1.Reset) error
+	Upgrade(UpgradeConfig) error
+	GetState() (State, error)
 }
 
 func NewRunner() Runner {
@@ -86,6 +116,59 @@ func (r *runner) Reset(conf elementalv1.Reset) error {
 	return cmd.Run()
 }
 
+func (r *runner) Upgrade(conf UpgradeConfig) error {
+	installerOpts := []string{"elemental"}
+	// There are no env var bindings in elemental-cli for elemental root options
+	// so root flags should be passed within the command line
+	if conf.Debug {
+		installerOpts = append(installerOpts, "--debug")
+	}
+
+	// Actual subcommand
+	if conf.RecoveryOnly {
+		installerOpts = append(installerOpts, "upgrade-recovery")
+	} else {
+		installerOpts = append(installerOpts, "upgrade")
+	}
+
+	if conf.Bootloader {
+		installerOpts = append(installerOpts, "--bootloader")
+	}
+
+	cmd := exec.Command("elemental")
+	environmentVariables := mapToUpgradeEnv(conf)
+	cmd.Env = append(os.Environ(), environmentVariables...)
+	cmd.Stdout = os.Stdout
+	cmd.Args = installerOpts
+	cmd.Stdin = os.Stdin
+	cmd.Stderr = os.Stderr
+	log.Debugf("running: %s\n with ENV:\n%s", strings.Join(installerOpts, " "), strings.Join(environmentVariables, "\n"))
+	return cmd.Run()
+}
+
+func (r *runner) GetState() (State, error) {
+	state := State{}
+
+	log.Debug("Getting elemental state")
+	installerOpts := []string{"elemental", "state"}
+	cmd := exec.Command("elemental")
+	cmd.Args = installerOpts
+	cmd.Stdin = os.Stdin
+	cmd.Stderr = os.Stderr
+	log.Debugf("running: %s", strings.Join(installerOpts, " "))
+
+	var commandOutput []byte
+	var err error
+	if commandOutput, err = cmd.Output(); err != nil {
+		return state, fmt.Errorf("running elemental state: %w", err)
+	}
+	if err := yaml.Unmarshal(commandOutput, &state); err != nil {
+		return state, fmt.Errorf("unmarshalling elemental state: %w", err)
+	}
+
+	return state, nil
+}
+
 func mapToInstallEnv(conf elementalv1.Install) []string {
 	var variables []string
 	// See GetInstallKeyEnvMap() in https://github.com/rancher/elemental-toolkit/blob/main/pkg/constants/constants.go
@@ -120,6 +203,27 @@ func mapToResetEnv(conf elementalv1.Reset) []string {
 	return variables
 }
 
+func mapToUpgradeEnv(conf UpgradeConfig) []string {
+	var variables []string
+	// See GetUpgradeKeyEnvMap() in https://github.com/rancher/elemental-toolkit/blob/main/pkg/constants/constants.go
+	variables = append(variables, formatEV("ELEMENTAL_UPGRADE_RECOVERY", strconv.FormatBool(conf.Recovery)))
+	variables = append(variables, formatEV("ELEMENTAL_UPGRADE_SNAPSHOT_LABELS", formatSnapshotLabels(conf.SnapshotLabels)))
+	if conf.RecoveryOnly {
+		variables = append(variables, formatEV("ELEMENTAL_UPGRADE_RECOVERY_SYSTEM", conf.System))
+	} else {
+		variables = append(variables, formatEV("ELEMENTAL_UPGRADE_SYSTEM", conf.System))
+	}
+	return variables
+}
+
 func formatEV(key string, value string) string {
 	return fmt.Sprintf("%s=%s", key, value)
 }
+
+func formatSnapshotLabels(labels map[string]string) string {
+	formattedLabels := []string{}
+	for key, value := range labels {
+		formattedLabels = append(formattedLabels, fmt.Sprintf("%s=%s", key, value))
+	}
+	return strings.Join(formattedLabels, ",")
+}