backups

type Backup ¶

type Backup interface {
	Backup(tmpdir string) error
}

Backup is an interface that enables different types of database backups, e.g. for backuping up a leveldb database (or multiple leveldb databases) vs a sqlite database. It is expected that the backup is written to the temporary directory specified by the input variable. It is unnecessary to compress the contents of the backup as the backup manager will compress the contents before transferring them to the backup storage location. Once the backup is complete (error or not) the tmpdir is removed.

type Buffer ¶

type Buffer struct {
	bytes.Buffer
}

func (Buffer) Close() error

type Config ¶

type Config struct {
	// If false, the backup manager will not run.
	Enabled bool `default:"false"`

	// The interval between backups.
	Interval time.Duration `default:"24h"`

	// The path to a local disk directory to store compressed backups, e.g.
	// file:///rel/path/ or a cloud location such as s3://bucket.
	StorageDSN string `split_words:"true" required:"true"`

	// Temporary directory to perform local backup to. If not set, then the OS tmpdir
	// is used. Backups are generated in this folder and then moved to the storage
	// location. This folder needs enough space to contain the complete backup.
	TempDir string `required:"false"`

	// Prefix specifies the filename of the backup, e.g.g prefix-200601021504.tgz
	Prefix string `default:"backup"`

	// The number of previous backup versions to keep.
	Keep int `default:"1"`
}

Configure the backup manager routine to ensure it is backing up the correct databases at the correct interval; removing old backups as necessary and storing the backups in the correct storage location.

func (c Config) ArchiveName() string

func (c Config) Storage() (_ Storage, err error)

type Discard ¶

type Discard struct{}

func (Discard) Close() error

func (Discard) Write(p []byte) (int, error)

type FileStorage ¶

type FileStorage struct {
	// contains filtered or unexported fields
}

FileStorage stores archived backups on a local disk. This is primarily used by mounting a second volume on a Kubernetes pod and saving the backups there or by writing to a network or RAID protected dis.

func NewFileStorage(root, prefix string) (_ *FileStorage, err error)

func (s *FileStorage) ListArchives() (paths []string, err error)

func (s *FileStorage) Open(name string) (_ io.WriteCloser, err error)

func (s *FileStorage) Remove(name string) error

type LevelDB ¶

type LevelDB struct {
	DB *leveldb.DB
}

LevelDB implements a single leveldb backup that takes a snapshot of the database and writes it to a second leveldb database at the temporary directory location.

func (l *LevelDB) Backup(tmpdir string) (err error)

type Manager ¶

type Manager struct {
	sync.Mutex
	// contains filtered or unexported fields
}

Manager runs as an independent service which periodically backs up a database to a compressed backup location on disk or to cloud storage. At a specified interval, the manager runs a db-specific backup routine that generally clones the database to a tmp directory; it then compresses the clone and moves it to a final backup location.

func New(conf Config, backup Backup) *Manager

func (m *Manager) MkdirTemp() (path string, err error)

func (m *Manager) Run() (err error)

func (m *Manager) Shutdown() error

type MemoryStorage ¶

type MemoryStorage struct {
	// contains filtered or unexported fields
}

Memory storage is primarily used for testing and writes backups to a bytes buffer. If /dev/null is specified as the "root" path, then a noop-closer is returned.

func (s *MemoryStorage) Backup(name string) (*Buffer, bool)

func (s *MemoryStorage) ListArchives() ([]string, error)

func (s *MemoryStorage) Open(name string) (io.WriteCloser, error)

func (s *MemoryStorage) Remove(name string) error

type SQLite3 ¶

type SQLite3 struct {
	DB   *sqlite.Conn
	Name string
}

SQLite3 implements a single sqlite3 backup that uses the online backup of a running database mechanism to copy the db over to a second sqlite3 database at the temporary directory location.

func (s *SQLite3) Backup(tmpdir string) (err error)

func (s *SQLite3) OpenDestDB(tmpdir string) (db *sql.DB, conn *sqlite.Conn, err error)

type Storage ¶

type Storage interface {
	Open(name string) (io.WriteCloser, error)
	Remove(name string) error
	ListArchives() ([]string, error)
}

Storage provides an interface for reading and writing compressed backups to disk.