docker-volume-backup/cmd/backup/script.go

522 lines
16 KiB
Go

// Copyright 2022 - Offen Authors <hioffen@posteo.de>
// SPDX-License-Identifier: MPL-2.0
package main
import (
"bytes"
"fmt"
"io"
"io/fs"
"log/slog"
"os"
"path"
"path/filepath"
"slices"
"strings"
"text/template"
"time"
"github.com/offen/docker-volume-backup/internal/storage"
"github.com/offen/docker-volume-backup/internal/storage/azure"
"github.com/offen/docker-volume-backup/internal/storage/dropbox"
"github.com/offen/docker-volume-backup/internal/storage/local"
"github.com/offen/docker-volume-backup/internal/storage/s3"
"github.com/offen/docker-volume-backup/internal/storage/ssh"
"github.com/offen/docker-volume-backup/internal/storage/webdav"
openpgp "github.com/ProtonMail/go-crypto/openpgp/v2"
"github.com/containrrr/shoutrrr"
"github.com/containrrr/shoutrrr/pkg/router"
"github.com/docker/docker/client"
"github.com/leekchan/timeutil"
"github.com/otiai10/copy"
"golang.org/x/sync/errgroup"
)
// script holds all the stateful information required to orchestrate a
// single backup run.
type script struct {
cli *client.Client
storages []storage.Backend
logger *slog.Logger
sender *router.ServiceRouter
template *template.Template
hooks []hook
hookLevel hookLevel
file string
stats *Stats
encounteredLock bool
c *Config
}
// newScript creates all resources needed for the script to perform actions against
// remote resources like the Docker engine or remote storage locations. All
// reading from env vars or other configuration sources is expected to happen
// in this method.
func newScript(c *Config, envVars map[string]string) (*script, func() error, error) {
stdOut, logBuffer := buffer(os.Stdout)
s := &script{
c: c,
logger: slog.New(slog.NewTextHandler(stdOut, nil)),
stats: &Stats{
StartTime: time.Now(),
LogOutput: logBuffer,
Storages: map[string]StorageStats{
"S3": {},
"WebDAV": {},
"SSH": {},
"Local": {},
"Azure": {},
"Dropbox": {},
},
},
}
unlock, err := s.lock("/var/lock/dockervolumebackup.lock")
if err != nil {
return nil, noop, fmt.Errorf("runScript: error acquiring file lock: %w", err)
}
for key, value := range envVars {
currentVal, currentOk := os.LookupEnv(key)
defer func(currentKey, currentVal string, currentOk bool) {
if !currentOk {
_ = os.Unsetenv(currentKey)
} else {
_ = os.Setenv(currentKey, currentVal)
}
}(key, currentVal, currentOk)
if err := os.Setenv(key, value); err != nil {
return nil, unlock, fmt.Errorf(
"Unexpected error overloading environment %s: %w",
s.c.BackupCronExpression,
err,
)
}
}
s.registerHook(hookLevelPlumbing, func(error) error {
s.stats.EndTime = time.Now()
s.stats.TookTime = s.stats.EndTime.Sub(s.stats.StartTime)
return nil
})
s.file = path.Join("/tmp", s.c.BackupFilename)
tmplFileName, tErr := template.New("extension").Parse(s.file)
if tErr != nil {
return nil, unlock, fmt.Errorf("newScript: unable to parse backup file extension template: %w", tErr)
}
var bf bytes.Buffer
if tErr := tmplFileName.Execute(&bf, map[string]string{
"Extension": fmt.Sprintf("tar.%s", s.c.BackupCompression),
}); tErr != nil {
return nil, unlock, fmt.Errorf("newScript: error executing backup file extension template: %w", tErr)
}
s.file = bf.String()
if s.c.BackupFilenameExpand {
s.file = os.ExpandEnv(s.file)
s.c.BackupLatestSymlink = os.ExpandEnv(s.c.BackupLatestSymlink)
s.c.BackupPruningPrefix = os.ExpandEnv(s.c.BackupPruningPrefix)
}
s.file = timeutil.Strftime(&s.stats.StartTime, s.file)
_, err = os.Stat("/var/run/docker.sock")
_, dockerHostSet := os.LookupEnv("DOCKER_HOST")
if !os.IsNotExist(err) || dockerHostSet {
cli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
if err != nil {
return nil, unlock, fmt.Errorf("newScript: failed to create docker client")
}
s.cli = cli
s.registerHook(hookLevelPlumbing, func(err error) error {
if err := s.cli.Close(); err != nil {
return fmt.Errorf("newScript: failed to close docker client: %w", err)
}
return nil
})
}
logFunc := func(logType storage.LogLevel, context string, msg string, params ...any) {
switch logType {
case storage.LogLevelWarning:
s.logger.Warn(fmt.Sprintf(msg, params...), "storage", context)
case storage.LogLevelError:
s.logger.Error(fmt.Sprintf(msg, params...), "storage", context)
default:
s.logger.Info(fmt.Sprintf(msg, params...), "storage", context)
}
}
if s.c.AwsS3BucketName != "" {
s3Config := s3.Config{
Endpoint: s.c.AwsEndpoint,
AccessKeyID: s.c.AwsAccessKeyID,
SecretAccessKey: s.c.AwsSecretAccessKey,
IamRoleEndpoint: s.c.AwsIamRoleEndpoint,
EndpointProto: s.c.AwsEndpointProto,
EndpointInsecure: s.c.AwsEndpointInsecure,
RemotePath: s.c.AwsS3Path,
BucketName: s.c.AwsS3BucketName,
StorageClass: s.c.AwsStorageClass,
CACert: s.c.AwsEndpointCACert.Cert,
PartSize: s.c.AwsPartSize,
}
s3Backend, err := s3.NewStorageBackend(s3Config, logFunc)
if err != nil {
return nil, unlock, fmt.Errorf("newScript: error creating s3 storage backend: %w", err)
}
s.storages = append(s.storages, s3Backend)
}
if s.c.WebdavUrl != "" {
webDavConfig := webdav.Config{
URL: s.c.WebdavUrl,
URLInsecure: s.c.WebdavUrlInsecure,
Username: s.c.WebdavUsername,
Password: s.c.WebdavPassword,
RemotePath: s.c.WebdavPath,
}
webdavBackend, err := webdav.NewStorageBackend(webDavConfig, logFunc)
if err != nil {
return nil, unlock, fmt.Errorf("newScript: error creating webdav storage backend: %w", err)
}
s.storages = append(s.storages, webdavBackend)
}
if s.c.SSHHostName != "" {
sshConfig := ssh.Config{
HostName: s.c.SSHHostName,
Port: s.c.SSHPort,
User: s.c.SSHUser,
Password: s.c.SSHPassword,
IdentityFile: s.c.SSHIdentityFile,
IdentityPassphrase: s.c.SSHIdentityPassphrase,
RemotePath: s.c.SSHRemotePath,
}
sshBackend, err := ssh.NewStorageBackend(sshConfig, logFunc)
if err != nil {
return nil, unlock, fmt.Errorf("newScript: error creating ssh storage backend: %w", err)
}
s.storages = append(s.storages, sshBackend)
}
if _, err := os.Stat(s.c.BackupArchive); !os.IsNotExist(err) {
localConfig := local.Config{
ArchivePath: s.c.BackupArchive,
LatestSymlink: s.c.BackupLatestSymlink,
}
localBackend := local.NewStorageBackend(localConfig, logFunc)
s.storages = append(s.storages, localBackend)
}
if s.c.AzureStorageAccountName != "" {
azureConfig := azure.Config{
ContainerName: s.c.AzureStorageContainerName,
AccountName: s.c.AzureStorageAccountName,
PrimaryAccountKey: s.c.AzureStoragePrimaryAccountKey,
Endpoint: s.c.AzureStorageEndpoint,
RemotePath: s.c.AzureStoragePath,
}
azureBackend, err := azure.NewStorageBackend(azureConfig, logFunc)
if err != nil {
return nil, unlock, fmt.Errorf("newScript: error creating azure storage backend: %w", err)
}
s.storages = append(s.storages, azureBackend)
}
if s.c.DropboxRefreshToken != "" && s.c.DropboxAppKey != "" && s.c.DropboxAppSecret != "" {
dropboxConfig := dropbox.Config{
Endpoint: s.c.DropboxEndpoint,
OAuth2Endpoint: s.c.DropboxOAuth2Endpoint,
RefreshToken: s.c.DropboxRefreshToken,
AppKey: s.c.DropboxAppKey,
AppSecret: s.c.DropboxAppSecret,
RemotePath: s.c.DropboxRemotePath,
ConcurrencyLevel: s.c.DropboxConcurrencyLevel.Int(),
}
dropboxBackend, err := dropbox.NewStorageBackend(dropboxConfig, logFunc)
if err != nil {
return nil, unlock, fmt.Errorf("newScript: error creating dropbox storage backend: %w", err)
}
s.storages = append(s.storages, dropboxBackend)
}
if s.c.EmailNotificationRecipient != "" {
emailURL := fmt.Sprintf(
"smtp://%s:%s@%s:%d/?from=%s&to=%s",
s.c.EmailSMTPUsername,
s.c.EmailSMTPPassword,
s.c.EmailSMTPHost,
s.c.EmailSMTPPort,
s.c.EmailNotificationSender,
s.c.EmailNotificationRecipient,
)
s.c.NotificationURLs = append(s.c.NotificationURLs, emailURL)
s.logger.Warn(
"Using EMAIL_* keys for providing notification configuration has been deprecated and will be removed in the next major version.",
)
s.logger.Warn(
"Please use NOTIFICATION_URLS instead. Refer to the README for an upgrade guide.",
)
}
hookLevel, ok := hookLevels[s.c.NotificationLevel]
if !ok {
return nil, unlock, fmt.Errorf("newScript: unknown NOTIFICATION_LEVEL %s", s.c.NotificationLevel)
}
s.hookLevel = hookLevel
if len(s.c.NotificationURLs) > 0 {
sender, senderErr := shoutrrr.CreateSender(s.c.NotificationURLs...)
if senderErr != nil {
return nil, unlock, fmt.Errorf("newScript: error creating sender: %w", senderErr)
}
s.sender = sender
tmpl := template.New("")
tmpl.Funcs(templateHelpers)
tmpl, err = tmpl.Parse(defaultNotifications)
if err != nil {
return nil, unlock, fmt.Errorf("newScript: unable to parse default notifications templates: %w", err)
}
if fi, err := os.Stat("/etc/dockervolumebackup/notifications.d"); err == nil && fi.IsDir() {
tmpl, err = tmpl.ParseGlob("/etc/dockervolumebackup/notifications.d/*.*")
if err != nil {
return nil, unlock, fmt.Errorf("newScript: unable to parse user defined notifications templates: %w", err)
}
}
s.template = tmpl
// To prevent duplicate notifications, ensure the regsistered callbacks
// run mutually exclusive.
s.registerHook(hookLevelError, func(err error) error {
if err == nil {
return nil
}
return s.notifyFailure(err)
})
s.registerHook(hookLevelInfo, func(err error) error {
if err != nil {
return nil
}
return s.notifySuccess()
})
}
return s, unlock, nil
}
// createArchive creates a tar archive of the configured backup location and
// saves it to disk.
func (s *script) createArchive() error {
backupSources := s.c.BackupSources
if s.c.BackupFromSnapshot {
s.logger.Warn(
"Using BACKUP_FROM_SNAPSHOT has been deprecated and will be removed in the next major version.",
)
s.logger.Warn(
"Please use `archive-pre` and `archive-post` commands to prepare your backup sources. Refer to the documentation for an upgrade guide.",
)
backupSources = filepath.Join("/tmp", s.c.BackupSources)
// copy before compressing guard against a situation where backup folder's content are still growing.
s.registerHook(hookLevelPlumbing, func(error) error {
if err := remove(backupSources); err != nil {
return fmt.Errorf("createArchive: error removing snapshot: %w", err)
}
s.logger.Info(
fmt.Sprintf("Removed snapshot `%s`.", backupSources),
)
return nil
})
if err := copy.Copy(s.c.BackupSources, backupSources, copy.Options{
PreserveTimes: true,
PreserveOwner: true,
}); err != nil {
return fmt.Errorf("createArchive: error creating snapshot: %w", err)
}
s.logger.Info(
fmt.Sprintf("Created snapshot of `%s` at `%s`.", s.c.BackupSources, backupSources),
)
}
tarFile := s.file
s.registerHook(hookLevelPlumbing, func(error) error {
if err := remove(tarFile); err != nil {
return fmt.Errorf("createArchive: error removing tar file: %w", err)
}
s.logger.Info(
fmt.Sprintf("Removed tar file `%s`.", tarFile),
)
return nil
})
backupPath, err := filepath.Abs(stripTrailingSlashes(backupSources))
if err != nil {
return fmt.Errorf("createArchive: error getting absolute path: %w", err)
}
var filesEligibleForBackup []string
if err := filepath.WalkDir(backupPath, func(path string, di fs.DirEntry, err error) error {
if err != nil {
return err
}
if s.c.BackupExcludeRegexp.Re != nil && s.c.BackupExcludeRegexp.Re.MatchString(path) {
return nil
}
filesEligibleForBackup = append(filesEligibleForBackup, path)
return nil
}); err != nil {
return fmt.Errorf("createArchive: error walking filesystem tree: %w", err)
}
if err := createArchive(filesEligibleForBackup, backupSources, tarFile, s.c.BackupCompression.String(), s.c.GzipParallelism.Int()); err != nil {
return fmt.Errorf("createArchive: error compressing backup folder: %w", err)
}
s.logger.Info(
fmt.Sprintf("Created backup of `%s` at `%s`.", backupSources, tarFile),
)
return nil
}
// encryptArchive encrypts the backup file using PGP and the configured passphrase.
// In case no passphrase is given it returns early, leaving the backup file
// untouched.
func (s *script) encryptArchive() error {
if s.c.GpgPassphrase == "" {
return nil
}
gpgFile := fmt.Sprintf("%s.gpg", s.file)
s.registerHook(hookLevelPlumbing, func(error) error {
if err := remove(gpgFile); err != nil {
return fmt.Errorf("encryptArchive: error removing gpg file: %w", err)
}
s.logger.Info(
fmt.Sprintf("Removed GPG file `%s`.", gpgFile),
)
return nil
})
outFile, err := os.Create(gpgFile)
if err != nil {
return fmt.Errorf("encryptArchive: error opening out file: %w", err)
}
defer outFile.Close()
_, name := path.Split(s.file)
dst, err := openpgp.SymmetricallyEncrypt(outFile, []byte(s.c.GpgPassphrase), &openpgp.FileHints{
FileName: name,
}, nil)
if err != nil {
return fmt.Errorf("encryptArchive: error encrypting backup file: %w", err)
}
defer dst.Close()
src, err := os.Open(s.file)
if err != nil {
return fmt.Errorf("encryptArchive: error opening backup file `%s`: %w", s.file, err)
}
if _, err := io.Copy(dst, src); err != nil {
return fmt.Errorf("encryptArchive: error writing ciphertext to file: %w", err)
}
s.file = gpgFile
s.logger.Info(
fmt.Sprintf("Encrypted backup using given passphrase, saving as `%s`.", s.file),
)
return nil
}
// copyArchive makes sure the backup file is copied to both local and remote locations
// as per the given configuration.
func (s *script) copyArchive() error {
_, name := path.Split(s.file)
if stat, err := os.Stat(s.file); err != nil {
return fmt.Errorf("copyArchive: unable to stat backup file: %w", err)
} else {
size := stat.Size()
s.stats.BackupFile = BackupFileStats{
Size: uint64(size),
Name: name,
FullPath: s.file,
}
}
eg := errgroup.Group{}
for _, backend := range s.storages {
b := backend
eg.Go(func() error {
return b.Copy(s.file)
})
}
if err := eg.Wait(); err != nil {
return fmt.Errorf("copyArchive: error copying archive: %w", err)
}
return nil
}
// pruneBackups rotates away backups from local and remote storages using
// the given configuration. In case the given configuration would delete all
// backups, it does nothing instead and logs a warning.
func (s *script) pruneBackups() error {
if s.c.BackupRetentionDays < 0 {
return nil
}
deadline := time.Now().AddDate(0, 0, -int(s.c.BackupRetentionDays)).Add(s.c.BackupPruningLeeway)
eg := errgroup.Group{}
for _, backend := range s.storages {
b := backend
eg.Go(func() error {
if skipPrune(b.Name(), s.c.BackupSkipBackendsFromPrune) {
s.logger.Info(
fmt.Sprintf("Skipping pruning for backend `%s`.", b.Name()),
)
return nil
}
stats, err := b.Prune(deadline, s.c.BackupPruningPrefix)
if err != nil {
return err
}
s.stats.Lock()
s.stats.Storages[b.Name()] = StorageStats{
Total: stats.Total,
Pruned: stats.Pruned,
}
s.stats.Unlock()
return nil
})
}
if err := eg.Wait(); err != nil {
return fmt.Errorf("pruneBackups: error pruning backups: %w", err)
}
return nil
}
// skipPrune returns true if the given backend name is contained in the
// list of skipped backends.
func skipPrune(name string, skippedBackends []string) bool {
return slices.ContainsFunc(
skippedBackends,
func(b string) bool {
return strings.EqualFold(b, name) // ignore case on both sides
},
)
}