WIP

Signed-off-by: Emmanuel Lodovice <[email protected]>

Author: emanlodovice

pkg/ruler/manager.go

@@ -44,6 +44,9 @@ type DefaultMultiTenantManager struct {
 	notifiers                 map[string]*rulerNotifier
 	notifiersDiscoveryMetrics map[string]discovery.DiscovererMetrics
 
+	// rules backup
+	rulesBackupManager *rulesBackupManager
+
 	managersTotal                 prometheus.Gauge
 	lastReloadSuccessful          *prometheus.GaugeVec
 	lastReloadSuccessfulTimestamp *prometheus.GaugeVec
@@ -85,6 +88,7 @@ func NewDefaultMultiTenantManager(cfg Config, managerFactory ManagerFactory, eva
 		mapper:                    newMapper(cfg.RulePath, logger),
 		userManagers:              map[string]RulesManager{},
 		userManagerMetrics:        userManagerMetrics,
+		rulesBackupManager:        newRulesBackupManager(cfg, logger),
 		managersTotal: promauto.With(reg).NewGauge(prometheus.GaugeOpts{
 			Namespace: "cortex",
 			Name:      "ruler_managers_total",
@@ -142,8 +146,12 @@ func (r *DefaultMultiTenantManager) SyncRuleGroups(ctx context.Context, ruleGrou
 	r.managersTotal.Set(float64(len(r.userManagers)))
 }
 
+func (r *DefaultMultiTenantManager) BackUpRuleGroups(ctx context.Context, ruleGroups map[string]rulespb.RuleGroupList) {
+	r.rulesBackupManager.backUpRuleGroups(ctx, ruleGroups)
+}
+
 // syncRulesToManager maps the rule files to disk, detects any changes and will create/update the
-// the users Prometheus Rules Manager.
+// users Prometheus Rules Manager.
 func (r *DefaultMultiTenantManager) syncRulesToManager(ctx context.Context, user string, groups rulespb.RuleGroupList) {
 	// Map the files to disk and return the file names to be passed to the users manager if they
 	// have been updated
@@ -279,6 +287,10 @@ func (r *DefaultMultiTenantManager) GetRules(userID string) []*promRules.Group {
 	return groups
 }
 
+func (r *DefaultMultiTenantManager) GetBackupRules(userID string) []*promRules.Group {
+	return r.rulesBackupManager.getRuleGroups(userID)
+}
+
 func (r *DefaultMultiTenantManager) Stop() {
 	r.notifiersMtx.Lock()
 	for _, n := range r.notifiers {

pkg/ruler/merger.go

@@ -0,0 +1,43 @@
+package ruler
+
+import (
+	"strings"
+	"time"
+
+	"golang.org/x/exp/slices"
+
+	promRules "github.com/prometheus/prometheus/rules"
+)
+
+func mergeGroupStateDesc(in []*GroupStateDesc) []*GroupStateDesc {
+	states := make(map[string]*GroupStateDesc)
+	rgTime := make(map[string]time.Time)
+	for _, state := range in {
+		latestTs := state.EvaluationTimestamp
+		for _, r := range state.ActiveRules {
+			if latestTs.Before(r.EvaluationTimestamp) {
+				latestTs = r.EvaluationTimestamp
+			}
+		}
+		key := promRules.GroupKey(state.Group.Namespace, state.Group.Name)
+		ts, ok := rgTime[key]
+		if !ok || ts.Before(latestTs) {
+			states[key] = state
+			rgTime[key] = latestTs
+		}
+	}
+	groups := make([]*GroupStateDesc, 0, len(states))
+	for _, state := range states {
+		groups = append(groups, state)
+	}
+	slices.SortFunc(groups, func(a, b *GroupStateDesc) int {
+		fileCompare := strings.Compare(a.Group.Namespace, b.Group.Namespace)
+
+		// If the namespace is the same, check the group name
+		if fileCompare != 0 {
+			return fileCompare
+		}
+		return strings.Compare(a.Group.Name, b.Group.Name)
+	})
+	return groups
+}

pkg/ruler/rule_backup_manager.go

@@ -0,0 +1,107 @@
+package ruler
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"sync"
+
+	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
+	"github.com/prometheus/prometheus/model/rulefmt"
+	"github.com/prometheus/prometheus/promql/parser"
+	promRules "github.com/prometheus/prometheus/rules"
+
+	"github.com/cortexproject/cortex/pkg/ruler/rulespb"
+)
+
+// Implements GroupLoader interface but instead of reading from a file when Load is called, it returns the
+// rulefmt.RuleGroup it has stored
+type loader struct {
+	ruleGroups map[string][]rulefmt.RuleGroup
+}
+
+func (r *loader) Load(identifier string) (*rulefmt.RuleGroups, []error) {
+	return &rulefmt.RuleGroups{
+		Groups: r.ruleGroups[identifier],
+	}, nil
+}
+
+func (r *loader) Parse(query string) (parser.Expr, error) {
+	return parser.ParseExpr(query)
+}
+
+type rulesBackupManager struct {
+	backupRuleGroupsMtx sync.RWMutex
+	backupRuleGroups    map[string][]*promRules.Group
+	cfg                 Config
+
+	logger log.Logger
+}
+
+func newRulesBackupManager(cfg Config, logger log.Logger) *rulesBackupManager {
+	return &rulesBackupManager{
+		backupRuleGroups: make(map[string][]*promRules.Group),
+		cfg:              cfg,
+		logger:           logger,
+	}
+}
+
+func (r *rulesBackupManager) backUpRuleGroups(_ context.Context, ruleGroups map[string]rulespb.RuleGroupList) {
+	r.backupRuleGroupsMtx.Lock()
+	defer r.backupRuleGroupsMtx.Unlock()
+	backupRuleGroups := make(map[string][]*promRules.Group)
+	for user, groups := range ruleGroups {
+		g, err := r.ruleGroupListToPromGroups(user, groups)
+		if err != nil {
+			// TODO: Increment a metric
+			level.Error(r.logger).Log("msg", "unable to back up rules", "user", user, "err", err)
+			continue
+		}
+		backupRuleGroups[user] = g
+	}
+	r.backupRuleGroups = backupRuleGroups
+}
+
+// ruleGroupListToPromGroups converts rulespb.RuleGroupList to []*promRules.Group by creating a single use
+// promRules.Manager and calling its LoadGroups method.
+func (r *rulesBackupManager) ruleGroupListToPromGroups(user string, ruleGroups rulespb.RuleGroupList) ([]*promRules.Group, error) {
+	rgs := ruleGroups.Formatted()
+
+	loader := &loader{
+		ruleGroups: rgs,
+	}
+	promManager := promRules.NewManager(&promRules.ManagerOptions{
+		ExternalURL: r.cfg.ExternalURL.URL,
+		GroupLoader: loader,
+	})
+
+	namespaces := make([]string, 0, len(rgs))
+	for k := range rgs {
+		namespaces = append(namespaces, k)
+	}
+	level.Info(r.logger).Log("msg", "backup rules for user", "user", user, "namespaces", strings.Join(namespaces, ","))
+	loadedGroups, errs := promManager.LoadGroups(r.cfg.EvaluationInterval, r.cfg.ExternalLabels, r.cfg.ExternalURL.String(), nil, namespaces...)
+	if errs != nil {
+		for _, e := range errs {
+			level.Error(r.logger).Log("msg", "loading groups to backup failed", "user", user, "namespaces", namespaces, "err", e)
+		}
+		return nil, errors.New("error loading rules to backup")
+	}
+
+	groups := make([]*promRules.Group, 0, len(loadedGroups))
+	for _, g := range loadedGroups {
+		groups = append(groups, g)
+	}
+	return groups, nil
+}
+
+func (r *rulesBackupManager) getRuleGroups(userID string) []*promRules.Group {
+	var result []*promRules.Group
+	r.backupRuleGroupsMtx.RLock()
+	defer r.backupRuleGroupsMtx.RUnlock()
+	if groups, exists := r.backupRuleGroups[userID]; exists {
+		result = groups
+	}
+	return result
+}