Alerting: Remove vendored models in migration service (#74503)

This PR replaces the vendored models in the migration with their equivalent ngalert models. It also replaces the raw SQL selects and inserts with service calls.

It also fills in some gaps in the testing suite around:

    - Migration of alert rules: verifying that the actual data model (queries, conditions) are correct 9a7cfa9
    - Secure settings migration: verifying that secure fields remain encrypted for all available notifiers and certain fields migrate from plain text to encrypted secure settings correctly e7d3993

Replacing the checks for custom dashboard ACLs will be replaced in a separate targeted PR as it will be complex enough alone.

pkg/services/sqlstore/migrations/ualert/created_folders_mig.go

@@ -0,0 +1,83 @@
+package ualert
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"xorm.io/xorm"
+
+	"github.com/grafana/grafana/pkg/services/sqlstore/migrator"
+)
+
+// stateKey is a vendored migrationStore.stateKey.
+var stateKey = "stateKey"
+
+// CreatedFoldersMigration moves the record of created folders during legacy migration from Dashboard created_by=-8
+// to the kvstore. If there are no dashboards with created_by=-.8, then nothing needs to be done.
+func CreatedFoldersMigration(mg *migrator.Migrator) {
+	mg.AddMigration("migrate record of created folders during legacy migration to kvstore", &createdFoldersToKVStore{})
+}
+
+type createdFoldersToKVStore struct {
+	migrator.MigrationBase
+}
+
+func (c createdFoldersToKVStore) SQL(migrator.Dialect) string {
+	return codeMigration
+}
+
+func (c createdFoldersToKVStore) Exec(sess *xorm.Session, mg *migrator.Migrator) error {
+	var results []struct {
+		UID   string `xorm:"uid"`
+		OrgID int64  `xorm:"org_id"`
+	}
+	folderCreatedBy := -8
+	if err := sess.SQL("select * from dashboard where created_by = ?", folderCreatedBy).Find(&results); err != nil {
+		return err
+	}
+
+	if len(results) == 0 {
+		mg.Logger.Debug("no dashboards with created_by=-8, nothing to set in kvstore")
+		return nil
+	}
+
+	type orgMigrationState struct {
+		OrgID          int64    `json:"orgId"`
+		CreatedFolders []string `json:"createdFolders"`
+	}
+	states := make(map[int64]*orgMigrationState)
+	for _, r := range results {
+		if _, ok := states[r.OrgID]; !ok {
+			states[r.OrgID] = &orgMigrationState{
+				OrgID:          r.OrgID,
+				CreatedFolders: []string{},
+			}
+		}
+		states[r.OrgID].CreatedFolders = append(states[r.OrgID].CreatedFolders, r.UID)
+	}
+
+	now := time.Now()
+	for _, state := range states {
+		raw, err := json.Marshal(state)
+		if err != nil {
+			return err
+		}
+
+		orgId := state.OrgID
+		entry := kvStoreV1Entry{
+			OrgID:     &orgId,
+			Namespace: &KVNamespace,
+			Key:       &stateKey,
+			Value:     string(raw),
+			Created:   now,
+			Updated:   now,
+		}
+		if _, errCreate := sess.Table("kv_store").Insert(&entry); errCreate != nil {
+			mg.Logger.Error("failed to insert record of created folders to kvstore", "err", errCreate)
+			return fmt.Errorf("failed to insert record of created folders to kvstore: %w", errCreate)
+		}
+	}
+
+	return nil
+}