/
main_migrate.go
706 lines (569 loc) · 16.8 KB
/
main_migrate.go
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package main
import (
"bufio"
"context"
"errors"
"fmt"
"os"
"os/exec"
"os/signal"
"path/filepath"
"runtime"
"sort"
"strings"
"github.com/spf13/cobra"
"golang.org/x/sys/unix"
"gopkg.in/yaml.v2"
"github.com/canonical/lxd/client"
"github.com/canonical/lxd/shared"
"github.com/canonical/lxd/shared/api"
cli "github.com/canonical/lxd/shared/cmd"
"github.com/canonical/lxd/shared/osarch"
"github.com/canonical/lxd/shared/revert"
"github.com/canonical/lxd/shared/units"
"github.com/canonical/lxd/shared/version"
)
type cmdMigrate struct {
global *cmdGlobal
flagRsyncArgs string
}
func (c *cmdMigrate) command() *cobra.Command {
cmd := &cobra.Command{}
cmd.Use = "lxd-migrate"
cmd.Short = "Physical to instance migration tool"
cmd.Long = `Description:
Physical to instance migration tool
This tool lets you turn any Linux filesystem (including your current one)
into a LXD instance on a remote LXD host.
It will setup a clean mount tree made of the root filesystem and any
additional mount you list, then transfer this through LXD's migration
API to create a new instance from it.
The same set of options as ` + "`lxc launch`" + ` are also supported.
`
cmd.RunE = c.run
cmd.Flags().StringVar(&c.flagRsyncArgs, "rsync-args", "", "Extra arguments to pass to rsync"+"``")
return cmd
}
type cmdMigrateData struct {
SourcePath string
Mounts []string
InstanceArgs api.InstancesPost
Project string
}
func (c *cmdMigrateData) render() string {
data := struct {
Name string `yaml:"Name"`
Project string `yaml:"Project"`
Type api.InstanceType `yaml:"Type"`
Source string `yaml:"Source"`
Mounts []string `yaml:"Mounts,omitempty"`
Profiles []string `yaml:"Profiles,omitempty"`
StoragePool string `yaml:"Storage pool,omitempty"`
StorageSize string `yaml:"Storage pool size,omitempty"`
Network string `yaml:"Network name,omitempty"`
Config map[string]string `yaml:"Config,omitempty"`
}{
c.InstanceArgs.Name,
c.Project,
c.InstanceArgs.Type,
c.SourcePath,
c.Mounts,
c.InstanceArgs.Profiles,
"",
"",
"",
c.InstanceArgs.Config,
}
disk, ok := c.InstanceArgs.Devices["root"]
if ok {
data.StoragePool = disk["pool"]
size, ok := disk["size"]
if ok {
data.StorageSize = size
}
}
network, ok := c.InstanceArgs.Devices["eth0"]
if ok {
data.Network = network["parent"]
}
out, err := yaml.Marshal(&data)
if err != nil {
return ""
}
return string(out)
}
func (c *cmdMigrate) askServer() (lxd.InstanceServer, string, error) {
// Server address
serverURL, err := c.global.asker.AskString("Please provide LXD server URL: ", "", nil)
if err != nil {
return nil, "", err
}
serverURL, err = parseURL(serverURL)
if err != nil {
return nil, "", err
}
args := lxd.ConnectionArgs{
UserAgent: fmt.Sprintf("LXC-MIGRATE %s", version.Version),
InsecureSkipVerify: true,
}
certificate, err := shared.GetRemoteCertificate(serverURL, args.UserAgent)
if err != nil {
return nil, "", fmt.Errorf("Failed to get remote certificate: %w", err)
}
digest := shared.CertFingerprint(certificate)
fmt.Println("Certificate fingerprint:", digest)
fmt.Print("ok (y/n)? ")
line, err := shared.ReadStdin()
if err != nil {
return nil, "", err
}
if len(line) < 1 || line[0] != 'y' && line[0] != 'Y' {
return nil, "", fmt.Errorf("Server certificate rejected by user")
}
server, err := lxd.ConnectLXD(serverURL, &args)
if err != nil {
return nil, "", fmt.Errorf("Failed to connect to server: %w", err)
}
apiServer, _, err := server.GetServer()
if err != nil {
return nil, "", fmt.Errorf("Failed to get server: %w", err)
}
fmt.Println("")
type AuthMethod int
const (
authMethodTLSCertificate AuthMethod = iota
authMethodTLSTemporaryCertificate
authMethodTLSCertificateToken
)
// TLS is always available for LXD servers
var availableAuthMethods []AuthMethod
var authMethod AuthMethod
i := 1
if shared.ValueInSlice(api.AuthenticationMethodTLS, apiServer.AuthMethods) {
fmt.Printf("%d) Use a certificate token\n", i)
availableAuthMethods = append(availableAuthMethods, authMethodTLSCertificateToken)
i++
fmt.Printf("%d) Use an existing TLS authentication certificate\n", i)
availableAuthMethods = append(availableAuthMethods, authMethodTLSCertificate)
i++
fmt.Printf("%d) Generate a temporary TLS authentication certificate\n", i)
availableAuthMethods = append(availableAuthMethods, authMethodTLSTemporaryCertificate)
}
if len(apiServer.AuthMethods) > 1 || shared.ValueInSlice(api.AuthenticationMethodTLS, apiServer.AuthMethods) {
authMethodInt, err := c.global.asker.AskInt("Please pick an authentication mechanism above: ", 1, int64(i), "", nil)
if err != nil {
return nil, "", err
}
authMethod = availableAuthMethods[authMethodInt-1]
}
var certPath string
var keyPath string
var token string
if authMethod == authMethodTLSCertificate {
certPath, err = c.global.asker.AskString("Please provide the certificate path: ", "", func(path string) error {
if !shared.PathExists(path) {
return errors.New("File does not exist")
}
return nil
})
if err != nil {
return nil, "", err
}
keyPath, err = c.global.asker.AskString("Please provide the keyfile path: ", "", func(path string) error {
if !shared.PathExists(path) {
return errors.New("File does not exist")
}
return nil
})
if err != nil {
return nil, "", err
}
} else if authMethod == authMethodTLSCertificateToken {
token, err = c.global.asker.AskString("Please provide the certificate token: ", "", func(token string) error {
_, err := shared.CertificateTokenDecode(token)
if err != nil {
return err
}
return nil
})
if err != nil {
return nil, "", err
}
}
var authType string
switch authMethod {
case authMethodTLSCertificate, authMethodTLSTemporaryCertificate, authMethodTLSCertificateToken:
authType = api.AuthenticationMethodTLS
}
return c.connectTarget(serverURL, certPath, keyPath, authType, token)
}
func (c *cmdMigrate) runInteractive(server lxd.InstanceServer) (cmdMigrateData, error) {
var err error
config := cmdMigrateData{}
config.InstanceArgs = api.InstancesPost{
Source: api.InstanceSource{
Type: "migration",
Mode: "push",
},
}
config.InstanceArgs.Config = map[string]string{}
config.InstanceArgs.Devices = map[string]map[string]string{}
// Provide instance type
instanceType, err := c.global.asker.AskInt("Would you like to create a container (1) or virtual-machine (2)?: ", 1, 2, "1", nil)
if err != nil {
return cmdMigrateData{}, err
}
if instanceType == 1 {
config.InstanceArgs.Type = api.InstanceTypeContainer
} else if instanceType == 2 {
config.InstanceArgs.Type = api.InstanceTypeVM
}
// Project
projectNames, err := server.GetProjectNames()
if err != nil {
return cmdMigrateData{}, err
}
if len(projectNames) > 1 {
project, err := c.global.asker.AskChoice("Project to create the instance in [default=default]: ", projectNames, "default")
if err != nil {
return cmdMigrateData{}, err
}
config.Project = project
} else {
config.Project = "default"
}
// Instance name
instanceNames, err := server.GetInstanceNames(api.InstanceTypeAny)
if err != nil {
return cmdMigrateData{}, err
}
for {
instanceName, err := c.global.asker.AskString("Name of the new instance: ", "", nil)
if err != nil {
return cmdMigrateData{}, err
}
if shared.ValueInSlice(instanceName, instanceNames) {
fmt.Printf("Instance %q already exists\n", instanceName)
continue
}
config.InstanceArgs.Name = instanceName
break
}
var question string
// Provide source path
if config.InstanceArgs.Type == api.InstanceTypeVM {
question = "Please provide the path to a disk, partition, or image file: "
} else {
question = "Please provide the path to a root filesystem: "
}
config.SourcePath, err = c.global.asker.AskString(question, "", func(s string) error {
if !shared.PathExists(s) {
return errors.New("Path does not exist")
}
_, err := os.Stat(s)
if err != nil {
return err
}
return nil
})
if err != nil {
return cmdMigrateData{}, err
}
if config.InstanceArgs.Type == api.InstanceTypeVM {
architectureName, _ := osarch.ArchitectureGetLocal()
if shared.ValueInSlice(architectureName, []string{"x86_64", "aarch64"}) {
hasSecureBoot, err := c.global.asker.AskBool("Does the VM support UEFI Secure Boot? [default=no]: ", "no")
if err != nil {
return cmdMigrateData{}, err
}
if !hasSecureBoot {
config.InstanceArgs.Config["security.secureboot"] = "false"
}
}
}
var mounts []string
// Additional mounts for containers
if config.InstanceArgs.Type == api.InstanceTypeContainer {
addMounts, err := c.global.asker.AskBool("Do you want to add additional filesystem mounts? [default=no]: ", "no")
if err != nil {
return cmdMigrateData{}, err
}
if addMounts {
for {
path, err := c.global.asker.AskString("Please provide a path the filesystem mount path [empty value to continue]: ", "", func(s string) error {
if s != "" {
if shared.PathExists(s) {
return nil
}
return errors.New("Path does not exist")
}
return nil
})
if err != nil {
return cmdMigrateData{}, err
}
if path == "" {
break
}
mounts = append(mounts, path)
}
config.Mounts = append(config.Mounts, mounts...)
}
}
for {
fmt.Println("\nInstance to be created:")
scanner := bufio.NewScanner(strings.NewReader(config.render()))
for scanner.Scan() {
fmt.Printf(" %s\n", scanner.Text())
}
fmt.Print(`
Additional overrides can be applied at this stage:
1) Begin the migration with the above configuration
2) Override profile list
3) Set additional configuration options
4) Change instance storage pool or volume size
5) Change instance network
`)
choice, err := c.global.asker.AskInt("Please pick one of the options above [default=1]: ", 1, 5, "1", nil)
if err != nil {
return cmdMigrateData{}, err
}
switch choice {
case 1:
return config, nil
case 2:
err = c.askProfiles(server, &config)
case 3:
err = c.askConfig(&config)
case 4:
err = c.askStorage(server, &config)
case 5:
err = c.askNetwork(server, &config)
}
if err != nil {
fmt.Println(err)
}
}
}
func (c *cmdMigrate) run(cmd *cobra.Command, args []string) error {
// Quick checks.
if os.Geteuid() != 0 {
return fmt.Errorf("This tool must be run as root")
}
_, err := exec.LookPath("rsync")
if err != nil {
return err
}
// Server
server, clientFingerprint, err := c.askServer()
if err != nil {
return err
}
sigChan := make(chan os.Signal, 1)
signal.Notify(sigChan, os.Interrupt)
ctx, cancel := context.WithCancel(context.Background())
go func() {
<-sigChan
if clientFingerprint != "" {
_ = server.DeleteCertificate(clientFingerprint)
}
cancel()
// The following nolint directive ignores the "deep-exit" rule of the revive linter.
// We should be exiting cleanly by passing the above context into each invoked method and checking for
// cancellation. Unfortunately our client methods do not accept a context argument.
os.Exit(1) //nolint:revive
}()
if clientFingerprint != "" {
defer func() { _ = server.DeleteCertificate(clientFingerprint) }()
}
config, err := c.runInteractive(server)
if err != nil {
return err
}
if config.Project != "" {
server = server.UseProject(config.Project)
}
config.Mounts = append(config.Mounts, config.SourcePath)
// Get and sort the mounts
sort.Strings(config.Mounts)
// Create the mount namespace and ensure we're not moved around
runtime.LockOSThread()
defer runtime.UnlockOSThread()
// Unshare a new mntns so our mounts don't leak
err = unix.Unshare(unix.CLONE_NEWNS)
if err != nil {
return fmt.Errorf("Failed to unshare mount namespace: %w", err)
}
// Prevent mount propagation back to initial namespace
err = unix.Mount("", "/", "", unix.MS_REC|unix.MS_PRIVATE, "")
if err != nil {
return fmt.Errorf("Failed to disable mount propagation: %w", err)
}
// Create the temporary directory to be used for the mounts
path, err := os.MkdirTemp("", "lxd-migrate_mount_")
if err != nil {
return err
}
// Automatically clean-up the temporary path on exit
defer func(path string) {
_ = unix.Unmount(path, unix.MNT_DETACH)
_ = os.Remove(path)
}(path)
var fullPath string
if config.InstanceArgs.Type == api.InstanceTypeContainer {
// Create the rootfs directory
fullPath = fmt.Sprintf("%s/rootfs", path)
err = os.Mkdir(fullPath, 0755)
if err != nil {
return err
}
// Setup the source (mounts)
err = setupSource(fullPath, config.Mounts)
if err != nil {
return fmt.Errorf("Failed to setup the source: %w", err)
}
} else {
fullPath = path
target := filepath.Join(path, "root.img")
err := os.WriteFile(target, nil, 0644)
if err != nil {
return fmt.Errorf("Failed to create %q: %w", target, err)
}
// Mount the path
err = unix.Mount(config.SourcePath, target, "none", unix.MS_BIND, "")
if err != nil {
return fmt.Errorf("Failed to mount %s: %w", config.SourcePath, err)
}
// Make it read-only
err = unix.Mount("", target, "none", unix.MS_BIND|unix.MS_RDONLY|unix.MS_REMOUNT, "")
if err != nil {
return fmt.Errorf("Failed to make %s read-only: %w", config.SourcePath, err)
}
}
// System architecture
architectureName, err := osarch.ArchitectureGetLocal()
if err != nil {
return err
}
config.InstanceArgs.Architecture = architectureName
revert := revert.New()
defer revert.Fail()
// Create the instance
op, err := server.CreateInstance(config.InstanceArgs)
if err != nil {
return err
}
revert.Add(func() {
_, _ = server.DeleteInstance(config.InstanceArgs.Name)
})
progress := cli.ProgressRenderer{Format: "Transferring instance: %s"}
_, err = op.AddHandler(progress.UpdateOp)
if err != nil {
progress.Done("")
return err
}
err = transferRootfs(ctx, server, op, fullPath, c.flagRsyncArgs, config.InstanceArgs.Type)
if err != nil {
return err
}
progress.Done(fmt.Sprintf("Instance %s successfully created", config.InstanceArgs.Name))
revert.Success()
return nil
}
func (c *cmdMigrate) askProfiles(server lxd.InstanceServer, config *cmdMigrateData) error {
profileNames, err := server.GetProfileNames()
if err != nil {
return err
}
profiles, err := c.global.asker.AskString("Which profiles do you want to apply to the instance? (space separated) [default=default, \"-\" for none]: ", "default", func(s string) error {
// This indicates that no profiles should be applied.
if s == "-" {
return nil
}
profiles := strings.Split(s, " ")
for _, profile := range profiles {
if !shared.ValueInSlice(profile, profileNames) {
return fmt.Errorf("Unknown profile %q", profile)
}
}
return nil
})
if err != nil {
return err
}
if profiles != "-" {
config.InstanceArgs.Profiles = strings.Split(profiles, " ")
}
return nil
}
func (c *cmdMigrate) askConfig(config *cmdMigrateData) error {
configs, err := c.global.asker.AskString("Please specify config keys and values (key=value ...): ", "", func(s string) error {
if s == "" {
return nil
}
for _, entry := range strings.Split(s, " ") {
if !strings.Contains(entry, "=") {
return fmt.Errorf("Bad key=value configuration: %v", entry)
}
}
return nil
})
if err != nil {
return err
}
for _, entry := range strings.Split(configs, " ") {
key, value, _ := strings.Cut(entry, "=")
config.InstanceArgs.Config[key] = value
}
return nil
}
func (c *cmdMigrate) askStorage(server lxd.InstanceServer, config *cmdMigrateData) error {
storagePools, err := server.GetStoragePoolNames()
if err != nil {
return err
}
if len(storagePools) == 0 {
return fmt.Errorf("No storage pools available")
}
storagePool, err := c.global.asker.AskChoice("Please provide the storage pool to use: ", storagePools, "")
if err != nil {
return err
}
config.InstanceArgs.Devices["root"] = map[string]string{
"type": "disk",
"pool": storagePool,
"path": "/",
}
changeStorageSize, err := c.global.asker.AskBool("Do you want to change the storage size? [default=no]: ", "no")
if err != nil {
return err
}
if changeStorageSize {
size, err := c.global.asker.AskString("Please specify the storage size: ", "", func(s string) error {
_, err := units.ParseByteSizeString(s)
return err
})
if err != nil {
return err
}
config.InstanceArgs.Devices["root"]["size"] = size
}
return nil
}
func (c *cmdMigrate) askNetwork(server lxd.InstanceServer, config *cmdMigrateData) error {
networks, err := server.GetNetworkNames()
if err != nil {
return err
}
network, err := c.global.asker.AskChoice("Please specify the network to use for the instance: ", networks, "")
if err != nil {
return err
}
config.InstanceArgs.Devices["eth0"] = map[string]string{
"type": "nic",
"nictype": "bridged",
"parent": network,
"name": "eth0",
}
return nil
}