Files
docker-volume-backup/cmd/backup/config.go

325 lines
13 KiB
Go

// Copyright 2022 - offen.software <hioffen@posteo.de>
// SPDX-License-Identifier: MPL-2.0
package main
import (
"bytes"
"crypto/x509"
"encoding/pem"
"fmt"
"os"
"regexp"
"strconv"
"strings"
"text/template"
"time"
"github.com/offen/docker-volume-backup/internal/errwrap"
)
// Config holds all configuration values that are expected to be set
// by users.
type Config struct {
AwsS3BucketName string `split_words:"true"`
AwsS3Path string `split_words:"true"`
AwsEndpoint string `split_words:"true" default:"s3.amazonaws.com"`
AwsEndpointProto string `split_words:"true" default:"https"`
AwsEndpointInsecure bool `split_words:"true"`
AwsEndpointCACert CertDecoder `envconfig:"AWS_ENDPOINT_CA_CERT"`
AwsStorageClass string `split_words:"true"`
AwsAccessKeyID string `envconfig:"AWS_ACCESS_KEY_ID"`
AwsSecretAccessKey string `split_words:"true"`
AwsIamRoleEndpoint string `split_words:"true"`
AwsPartSize int64 `split_words:"true"`
BackupCompression CompressionType `split_words:"true" default:"gz"`
GzipParallelism WholeNumber `split_words:"true" default:"1"`
BackupSources string `split_words:"true" default:"/backup"`
BackupFilename string `split_words:"true" default:"backup-%Y-%m-%dT%H-%M-%S.{{ .Extension }}"`
BackupFilenameExpand bool `split_words:"true"`
BackupLatestSymlink string `split_words:"true"`
BackupArchive string `split_words:"true" default:"/archive"`
BackupCronExpression string `split_words:"true" default:"@daily"`
BackupJitter time.Duration `split_words:"true" default:"0s"`
BackupRetentionDays int32 `split_words:"true" default:"-1"`
BackupPruningLeeway time.Duration `split_words:"true" default:"1m"`
BackupPruningPrefix string `split_words:"true"`
BackupStopContainerLabel string `split_words:"true"`
BackupStopDuringBackupLabel string `split_words:"true" default:"true"`
BackupStopDuringBackupNoRestartLabel string `split_words:"true" default:"true"`
BackupStopServiceTimeout time.Duration `split_words:"true" default:"5m"`
BackupFromSnapshot bool `split_words:"true"`
BackupExcludeRegexp RegexpDecoder `split_words:"true"`
BackupSkipBackendsFromPrune []string `split_words:"true"`
GpgPassphrase string `split_words:"true"`
GpgPublicKeyRing string `split_words:"true"`
AgePassphrase string `split_words:"true"`
AgePublicKeys []string `split_words:"true"`
NotificationURLs []string `envconfig:"NOTIFICATION_URLS"`
NotificationLevel string `split_words:"true" default:"error"`
EmailNotificationRecipient string `split_words:"true"`
EmailNotificationSender string `split_words:"true" default:"noreply@nohost"`
EmailSMTPHost string `envconfig:"EMAIL_SMTP_HOST"`
EmailSMTPPort int `envconfig:"EMAIL_SMTP_PORT" default:"587"`
EmailSMTPUsername string `envconfig:"EMAIL_SMTP_USERNAME"`
EmailSMTPPassword string `envconfig:"EMAIL_SMTP_PASSWORD"`
WebdavUrl string `split_words:"true"`
WebdavUrlInsecure bool `split_words:"true"`
WebdavPath string `split_words:"true" default:"/"`
WebdavUsername string `split_words:"true"`
WebdavPassword string `split_words:"true"`
SSHHostName string `split_words:"true"`
SSHPort string `split_words:"true" default:"22"`
SSHUser string `split_words:"true"`
SSHPassword string `split_words:"true"`
SSHIdentityFile string `split_words:"true" default:"/root/.ssh/id_rsa"`
SSHIdentityPassphrase string `split_words:"true"`
SSHRemotePath string `split_words:"true"`
ExecLabel string `split_words:"true"`
ExecForwardOutput bool `split_words:"true"`
LockTimeout time.Duration `split_words:"true" default:"60m"`
AzureStorageAccountName string `split_words:"true"`
AzureStoragePrimaryAccountKey string `split_words:"true"`
AzureStorageConnectionString string `split_words:"true"`
AzureStorageContainerName string `split_words:"true"`
AzureStoragePath string `split_words:"true"`
AzureStorageEndpoint string `split_words:"true" default:"https://{{ .AccountName }}.blob.core.windows.net/"`
AzureStorageAccessTier string `split_words:"true"`
DropboxEndpoint string `split_words:"true" default:"https://api.dropbox.com/"`
DropboxOAuth2Endpoint string `envconfig:"DROPBOX_OAUTH2_ENDPOINT" default:"https://api.dropbox.com/"`
DropboxRefreshToken string `split_words:"true"`
DropboxAppKey string `split_words:"true"`
DropboxAppSecret string `split_words:"true"`
DropboxRemotePath string `split_words:"true"`
DropboxConcurrencyLevel NaturalNumber `split_words:"true" default:"6"`
GoogleDriveCredentialsJSON string `split_words:"true"`
GoogleDriveFolderID string `split_words:"true"`
GoogleDriveImpersonateSubject string `split_words:"true"`
GoogleDriveEndpoint string `split_words:"true"`
GoogleDriveTokenURL string `split_words:"true"`
source string
additionalEnvVars map[string]string
}
type CompressionType string
func (c *CompressionType) Decode(v string) error {
switch v {
case "none", "gz", "zst":
*c = CompressionType(v)
return nil
default:
return errwrap.Wrap(nil, fmt.Sprintf("error decoding compression type %s", v))
}
}
func (c *CompressionType) String() string {
return string(*c)
}
type CertDecoder struct {
Cert *x509.Certificate
}
func (c *CertDecoder) Decode(v string) error {
if v == "" {
return nil
}
content, err := os.ReadFile(v)
if err != nil {
content = []byte(v)
}
block, _ := pem.Decode(content)
cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
return errwrap.Wrap(err, "error parsing certificate")
}
*c = CertDecoder{Cert: cert}
return nil
}
type RegexpDecoder struct {
Re *regexp.Regexp
}
func (r *RegexpDecoder) Decode(v string) error {
if v == "" {
return nil
}
re, err := regexp.Compile(v)
if err != nil {
return errwrap.Wrap(err, fmt.Sprintf("error compiling given regexp `%s`", v))
}
*r = RegexpDecoder{Re: re}
return nil
}
// NaturalNumber is a type that can be used to decode a positive, non-zero natural number
type NaturalNumber int
func (n *NaturalNumber) Decode(v string) error {
asInt, err := strconv.Atoi(v)
if err != nil {
return errwrap.Wrap(nil, fmt.Sprintf("error converting %s to int", v))
}
if asInt <= 0 {
return errwrap.Wrap(nil, fmt.Sprintf("expected a natural number, got %d", asInt))
}
*n = NaturalNumber(asInt)
return nil
}
func (n *NaturalNumber) Int() int {
return int(*n)
}
// WholeNumber is a type that can be used to decode a positive whole number, including zero
type WholeNumber int
func (n *WholeNumber) Decode(v string) error {
asInt, err := strconv.Atoi(v)
if err != nil {
return errwrap.Wrap(nil, fmt.Sprintf("error converting %s to int", v))
}
if asInt < 0 {
return errwrap.Wrap(nil, fmt.Sprintf("expected a whole, positive number, including zero. Got %d", asInt))
}
*n = WholeNumber(asInt)
return nil
}
func (n *WholeNumber) Int() int {
return int(*n)
}
type envVarLookup struct {
ok bool
key string
value string
}
// applyEnv sets the values in `additionalEnvVars` as environment variables.
// It returns a function that reverts all values that have been set to its
// previous state.
func (c *Config) applyEnv() (func() error, error) {
lookups := []envVarLookup{}
unset := func() error {
for _, lookup := range lookups {
if !lookup.ok {
if err := os.Unsetenv(lookup.key); err != nil {
return errwrap.Wrap(err, fmt.Sprintf("error unsetting env var %s", lookup.key))
}
continue
}
if err := os.Setenv(lookup.key, lookup.value); err != nil {
return errwrap.Wrap(err, fmt.Sprintf("error setting back env var %s", lookup.key))
}
}
return nil
}
for key, value := range c.additionalEnvVars {
current, ok := os.LookupEnv(key)
lookups = append(lookups, envVarLookup{ok: ok, key: key, value: current})
if err := os.Setenv(key, value); err != nil {
return unset, errwrap.Wrap(err, "error setting env var")
}
}
return unset, nil
}
// resolve is responsible for performing all implicit logic that transforms a configuration object
// into what is actually being used at runtime. E.g. environment variables are expanded or
// deprecated config options are transposed into their up to date successors. The caller is
// responsible for calling the returned reset function after usage of the config is done.
func (c *Config) resolve() (reset func() error, warnings []string, err error) {
reset, aErr := c.applyEnv()
if aErr != nil {
err = errwrap.Wrap(aErr, "error applying env")
return
}
if _, ok := hookLevels[c.NotificationLevel]; !ok {
err = errwrap.Wrap(nil, fmt.Sprintf("unknown NOTIFICATION_LEVEL %s", c.NotificationLevel))
return
}
if c.BackupFilenameExpand {
c.BackupFilename = os.ExpandEnv(c.BackupFilename)
c.BackupLatestSymlink = os.ExpandEnv(c.BackupLatestSymlink)
c.BackupPruningPrefix = os.ExpandEnv(c.BackupPruningPrefix)
}
if c.EmailNotificationRecipient != "" {
emailURL := fmt.Sprintf(
"smtp://%s:%s@%s:%d/?from=%s&to=%s",
c.EmailSMTPUsername,
c.EmailSMTPPassword,
c.EmailSMTPHost,
c.EmailSMTPPort,
c.EmailNotificationSender,
c.EmailNotificationRecipient,
)
c.NotificationURLs = append(c.NotificationURLs, emailURL)
warnings = append(warnings,
"Using EMAIL_* keys for providing notification configuration has been deprecated and will be removed in the next major version.",
"Please use NOTIFICATION_URLS instead. Refer to the README for an upgrade guide.",
)
}
if c.BackupFromSnapshot {
warnings = append(warnings,
"Using BACKUP_FROM_SNAPSHOT has been deprecated and will be removed in the next major version.",
"Please use `archive-pre` and `archive-post` commands to prepare your backup sources. Refer to the documentation for an upgrade guide.",
)
}
if c.BackupStopDuringBackupLabel != "" && c.BackupStopContainerLabel != "" {
err = errwrap.Wrap(nil, "both BACKUP_STOP_DURING_BACKUP_LABEL and BACKUP_STOP_CONTAINER_LABEL have been set, cannot continue")
return
}
if c.BackupStopContainerLabel != "" {
warnings = append(warnings,
"Using BACKUP_STOP_CONTAINER_LABEL has been deprecated and will be removed in the next major version.",
"Please use BACKUP_STOP_DURING_BACKUP_LABEL instead. Refer to the docs for an upgrade guide.",
)
c.BackupStopDuringBackupLabel = c.BackupStopContainerLabel
}
tmplFileName, tErr := template.New("extension").Parse(c.BackupFilename)
if tErr != nil {
err = errwrap.Wrap(tErr, "unable to parse backup file extension template")
return
}
var bf bytes.Buffer
if tErr := tmplFileName.Execute(&bf, map[string]string{
"Extension": func() string {
if c.BackupCompression == "none" {
return "tar"
}
return fmt.Sprintf("tar.%s", c.BackupCompression)
}(),
}); tErr != nil {
err = errwrap.Wrap(tErr, "error executing backup file extension template")
return
}
c.BackupFilename = bf.String()
if c.AzureStorageEndpoint != "" {
endpointTemplate, tErr := template.New("endpoint").Parse(c.AzureStorageEndpoint)
if tErr != nil {
err = errwrap.Wrap(tErr, "error parsing endpoint template")
return
}
var ep bytes.Buffer
if tErr := endpointTemplate.Execute(&ep, map[string]string{"AccountName": c.AzureStorageAccountName}); tErr != nil {
err = errwrap.Wrap(tErr, "error executing endpoint template")
return
}
c.AzureStorageEndpoint = fmt.Sprintf("%s/", strings.TrimSuffix(ep.String(), "/"))
}
return
}