grafana/pkg/services/ngalert/notifier/file_store.go
Matthew Jacobson 0c3c5c5607
Alerting: Stop persisting silences and nflog to disk (#84706)
With this change, we no longer need to persist silence/nflog states to disk in addition to the kvstore
2024-03-23 00:37:33 +02:00

100 lines
3.1 KiB
Go

package notifier
import (
"context"
"encoding/base64"
"fmt"
alertingNotify "github.com/grafana/alerting/notify"
"github.com/grafana/grafana/pkg/infra/kvstore"
"github.com/grafana/grafana/pkg/infra/log"
)
const (
KVNamespace = "alertmanager"
NotificationLogFilename = "notifications"
SilencesFilename = "silences"
)
// FileStore is in charge of persisting the alertmanager files to the database.
// It uses the KVstore table and encodes the files as a base64 string.
type FileStore struct {
kv *kvstore.NamespacedKVStore
orgID int64
logger log.Logger
}
func NewFileStore(orgID int64, store kvstore.KVStore) *FileStore {
return &FileStore{
orgID: orgID,
kv: kvstore.WithNamespace(store, orgID, KVNamespace),
logger: log.New("ngalert.notifier.alertmanager.file_store", orgID),
}
}
// GetSilences returns the content of the silences file from kvstore.
func (fileStore *FileStore) GetSilences(ctx context.Context) (string, error) {
return fileStore.contentFor(ctx, SilencesFilename)
}
func (fileStore *FileStore) GetNotificationLog(ctx context.Context) (string, error) {
return fileStore.contentFor(ctx, NotificationLogFilename)
}
// contentFor returns the content for the given Alertmanager kvstore key.
func (fileStore *FileStore) contentFor(ctx context.Context, filename string) (string, error) {
// Then, let's attempt to read it from the database.
content, exists, err := fileStore.kv.Get(ctx, filename)
if err != nil {
return "", fmt.Errorf("error reading file '%s' from database: %w", filename, err)
}
// File doesn't exist, Alertmanager will eventually save it to the database.
if !exists {
return "", nil
}
// If we have a file stored in the database, let's decode it and write it to disk to perform that initial load to memory.
bytes, err := decode(content)
if err != nil {
return "", fmt.Errorf("error decoding file '%s': %w", filename, err)
}
return string(bytes), err
}
// SaveSilences saves the silences to the database and returns the size of the unencoded state.
func (fileStore *FileStore) SaveSilences(ctx context.Context, st alertingNotify.State) (int64, error) {
return fileStore.persist(ctx, SilencesFilename, st)
}
// SaveNotificationLog saves the notification log to the database and returns the size of the unencoded state.
func (fileStore *FileStore) SaveNotificationLog(ctx context.Context, st alertingNotify.State) (int64, error) {
return fileStore.persist(ctx, NotificationLogFilename, st)
}
// persist takes care of persisting the binary representation of internal state to the database as a base64 encoded string.
func (fileStore *FileStore) persist(ctx context.Context, filename string, st alertingNotify.State) (int64, error) {
var size int64
bytes, err := st.MarshalBinary()
if err != nil {
return size, err
}
if err = fileStore.kv.Set(ctx, filename, encode(bytes)); err != nil {
return size, err
}
return int64(len(bytes)), err
}
func decode(s string) ([]byte, error) {
return base64.StdEncoding.DecodeString(s)
}
func encode(b []byte) string {
return base64.StdEncoding.EncodeToString(b)
}