open-vault/sdk/framework/wal.go
2019-04-12 17:54:35 -04:00

102 lines
2.5 KiB
Go

package framework
import (
"context"
"encoding/json"
"strings"
"time"
uuid "github.com/hashicorp/go-uuid"
"github.com/hashicorp/vault/sdk/helper/jsonutil"
"github.com/hashicorp/vault/sdk/logical"
)
// WALPrefix is the prefix within Storage where WAL entries will be written.
const WALPrefix = "wal/"
type WALEntry struct {
ID string `json:"-"`
Kind string `json:"type"`
Data interface{} `json:"data"`
CreatedAt int64 `json:"created_at"`
}
// PutWAL writes some data to the WAL.
//
// The kind parameter is used by the framework to allow users to store
// multiple kinds of WAL data and to easily disambiguate what data they're
// expecting.
//
// Data within the WAL that is uncommitted (CommitWAL hasn't be called)
// will be given to the rollback callback when an rollback operation is
// received, allowing the backend to clean up some partial states.
//
// The data must be JSON encodable.
//
// This returns a unique ID that can be used to reference this WAL data.
// WAL data cannot be modified. You can only add to the WAL and commit existing
// WAL entries.
func PutWAL(ctx context.Context, s logical.Storage, kind string, data interface{}) (string, error) {
value, err := json.Marshal(&WALEntry{
Kind: kind,
Data: data,
CreatedAt: time.Now().UTC().Unix(),
})
if err != nil {
return "", err
}
id, err := uuid.GenerateUUID()
if err != nil {
return "", err
}
return id, s.Put(ctx, &logical.StorageEntry{
Key: WALPrefix + id,
Value: value,
})
}
// GetWAL reads a specific entry from the WAL. If the entry doesn't exist,
// then nil value is returned.
//
// The kind, value, and error are returned.
func GetWAL(ctx context.Context, s logical.Storage, id string) (*WALEntry, error) {
entry, err := s.Get(ctx, WALPrefix+id)
if err != nil {
return nil, err
}
if entry == nil {
return nil, nil
}
var raw WALEntry
if err := jsonutil.DecodeJSON(entry.Value, &raw); err != nil {
return nil, err
}
raw.ID = id
return &raw, nil
}
// DeleteWAL commits the WAL entry with the given ID. Once committed,
// it is assumed that the operation was a success and doesn't need to
// be rolled back.
func DeleteWAL(ctx context.Context, s logical.Storage, id string) error {
return s.Delete(ctx, WALPrefix+id)
}
// ListWAL lists all the entries in the WAL.
func ListWAL(ctx context.Context, s logical.Storage) ([]string, error) {
keys, err := s.List(ctx, WALPrefix)
if err != nil {
return nil, err
}
for i, k := range keys {
keys[i] = strings.TrimPrefix(k, WALPrefix)
}
return keys, nil
}