lnd.xprv/lncfg/db.go
Olaoluwa Osuntokun 7355c8ba3a
lncfg: add new GetBackends which returns active DB backends
In this commit, we modify the existing `GetBackend` method to now be
called `GetBackends`. This new method will populate a new `RemoteDB`
attribute based on if the replicated backend is active or not. As is,
the local backend is used everywhere. An upcoming commit will once again
re-enable the remote backend, in a hybrid manner.
2020-08-07 18:44:00 -07:00

99 lines
2.4 KiB
Go

package lncfg
import (
"context"
"fmt"
"github.com/lightningnetwork/lnd/channeldb/kvdb"
)
const (
dbName = "channel.db"
BoltBackend = "bolt"
EtcdBackend = "etcd"
)
// DB holds database configuration for LND.
type DB struct {
Backend string `long:"backend" description:"The selected database backend."`
Etcd *kvdb.EtcdConfig `group:"etcd" namespace:"etcd" description:"Etcd settings."`
Bolt *kvdb.BoltConfig `group:"bolt" namespace:"bolt" description:"Bolt settings."`
}
// NewDB creates and returns a new default DB config.
func DefaultDB() *DB {
return &DB{
Backend: BoltBackend,
Bolt: &kvdb.BoltConfig{},
}
}
// Validate validates the DB config.
func (db *DB) Validate() error {
switch db.Backend {
case BoltBackend:
case EtcdBackend:
if db.Etcd.Host == "" {
return fmt.Errorf("etcd host must be set")
}
default:
return fmt.Errorf("unknown backend, must be either \"%v\" or \"%v\"",
BoltBackend, EtcdBackend)
}
return nil
}
// DatabaseBackends is a two-tuple that holds the set of active database
// backends for the daemon. The two backends we expose are the local database
// backend, and the remote backend. The LocalDB attribute will always be
// populated. However, the remote DB will only be set if a replicated database
// is active.
type DatabaseBackends struct {
// LocalDB points to the local non-replicated backend.
LocalDB kvdb.Backend
// RemoteDB points to a possibly networked replicated backend. If no
// replicated backend is active, then this pointer will be nil.
RemoteDB kvdb.Backend
}
// GetBackends returns a set of kvdb.Backends as set in the DB config. The
// local database will ALWAYS be non-nil, while the remote database will only
// be populated if etcd is specified.
func (db *DB) GetBackends(ctx context.Context, dbPath string,
networkName string) (*DatabaseBackends, error) {
var (
localDB, remoteDB kvdb.Backend
err error
)
if db.Backend == EtcdBackend {
// Prefix will separate key/values in the db.
remoteDB, err = kvdb.GetEtcdBackend(ctx, networkName, db.Etcd)
if err != nil {
return nil, err
}
}
localDB, err = kvdb.GetBoltBackend(
dbPath, dbName, !db.Bolt.SyncFreelist,
)
if err != nil {
return nil, err
}
return &DatabaseBackends{
LocalDB: localDB,
RemoteDB: remoteDB,
}, nil
}
// Compile-time constraint to ensure Workers implements the Validator interface.
var _ Validator = (*DB)(nil)