General cleanup of rules.

rules/alerting.go

@@ -16,7 +16,6 @@ package rules
 import (
 	"fmt"
 	"html/template"
-	"strings"
 	"sync"
 	"time"
 
@@ -28,12 +27,12 @@ import (
 
 const (
 	// AlertMetricName is the metric name for synthetic alert timeseries.
-	AlertMetricName clientmodel.LabelValue = "ALERTS"
+	alertMetricName clientmodel.LabelValue = "ALERTS"
 
 	// AlertNameLabel is the label name indicating the name of an alert.
-	AlertNameLabel clientmodel.LabelName = "alertname"
+	alertNameLabel clientmodel.LabelName = "alertname"
 	// AlertStateLabel is the label name indicating the state of an alert.
-	AlertStateLabel clientmodel.LabelName = "alertstate"
+	alertStateLabel clientmodel.LabelName = "alertstate"
 )
 
 // AlertState denotes the state of an active alert.
@@ -41,11 +40,11 @@ type AlertState int
 
 func (s AlertState) String() string {
 	switch s {
-	case Inactive:
+	case StateInactive:
 		return "inactive"
-	case Pending:
+	case StatePending:
 		return "pending"
-	case Firing:
+	case StateFiring:
 		return "firing"
 	default:
 		panic("undefined")
@@ -54,13 +53,13 @@ func (s AlertState) String() string {
 
 const (
 	// Inactive alerts are neither firing nor pending.
-	Inactive AlertState = iota
+	StateInactive AlertState = iota
 	// Pending alerts have been active for less than the configured
 	// threshold duration.
-	Pending
+	StatePending
 	// Firing alerts have been active for longer than the configured
 	// threshold duration.
-	Firing
+	StateFiring
 )
 
 // Alert is used to track active (pending/firing) alerts over time.
@@ -84,9 +83,9 @@ func (a Alert) sample(timestamp clientmodel.Timestamp, value clientmodel.SampleV
 		recordedMetric[label] = value
 	}
 
-	recordedMetric[clientmodel.MetricNameLabel] = AlertMetricName
+	recordedMetric[clientmodel.MetricNameLabel] = alertMetricName
-	recordedMetric[AlertNameLabel] = clientmodel.LabelValue(a.Name)
+	recordedMetric[alertNameLabel] = clientmodel.LabelValue(a.Name)
-	recordedMetric[AlertStateLabel] = clientmodel.LabelValue(a.State.String())
+	recordedMetric[alertStateLabel] = clientmodel.LabelValue(a.State.String())
 
 	return &promql.Sample{
 		Metric: clientmodel.COWMetric{
@@ -103,16 +102,16 @@ type AlertingRule struct {
 	// The name of the alert.
 	name string
 	// The vector expression from which to generate alerts.
-	Vector promql.Expr
+	vector promql.Expr
 	// The duration for which a labelset needs to persist in the expression
 	// output vector before an alert transitions from Pending to Firing state.
 	holdDuration time.Duration
 	// Extra labels to attach to the resulting alert sample vectors.
-	Labels clientmodel.LabelSet
+	labels clientmodel.LabelSet
 	// Short alert summary, suitable for email subjects.
-	Summary string
+	summary string
 	// More detailed alert description.
-	Description string
+	description string
 
 	// Protects the below.
 	mutex sync.Mutex
@@ -121,15 +120,36 @@ type AlertingRule struct {
 	activeAlerts map[clientmodel.Fingerprint]*Alert
 }
 
+// NewAlertingRule constructs a new AlertingRule.
+func NewAlertingRule(
+	name string,
+	vector promql.Expr,
+	holdDuration time.Duration,
+	labels clientmodel.LabelSet,
+	summary string,
+	description string,
+) *AlertingRule {
+	return &AlertingRule{
+		name:         name,
+		vector:       vector,
+		holdDuration: holdDuration,
+		labels:       labels,
+		summary:      summary,
+		description:  description,
+
+		activeAlerts: map[clientmodel.Fingerprint]*Alert{},
+	}
+}
+
 // Name returns the name of the alert.
 func (rule *AlertingRule) Name() string {
 	return rule.name
 }
 
-// Eval evaluates the rule expression and then creates pending alerts and fires
+// eval evaluates the rule expression and then creates pending alerts and fires
 // or removes previously pending alerts accordingly.
-func (rule *AlertingRule) Eval(timestamp clientmodel.Timestamp, engine *promql.Engine) (promql.Vector, error) {
+func (rule *AlertingRule) eval(timestamp clientmodel.Timestamp, engine *promql.Engine) (promql.Vector, error) {
-	query, err := engine.NewInstantQuery(rule.Vector.String(), timestamp)
+	query, err := engine.NewInstantQuery(rule.vector.String(), timestamp)
 	if err != nil {
 		return nil, err
 	}
@@ -151,14 +171,14 @@ func (rule *AlertingRule) Eval(timestamp clientmodel.Timestamp, engine *promql.E
 		if alert, ok := rule.activeAlerts[fp]; !ok {
 			labels := clientmodel.LabelSet{}
 			labels.MergeFromMetric(sample.Metric.Metric)
-			labels = labels.Merge(rule.Labels)
+			labels = labels.Merge(rule.labels)
 			if _, ok := labels[clientmodel.MetricNameLabel]; ok {
 				delete(labels, clientmodel.MetricNameLabel)
 			}
 			rule.activeAlerts[fp] = &Alert{
 				Name:        rule.name,
 				Labels:      labels,
-				State:       Pending,
+				State:       StatePending,
 				ActiveSince: timestamp,
 				Value:       sample.Value,
 			}
@@ -177,9 +197,9 @@ func (rule *AlertingRule) Eval(timestamp clientmodel.Timestamp, engine *promql.E
 			continue
 		}
 
-		if activeAlert.State == Pending && timestamp.Sub(activeAlert.ActiveSince) >= rule.holdDuration {
+		if activeAlert.State == StatePending && timestamp.Sub(activeAlert.ActiveSince) >= rule.holdDuration {
 			vector = append(vector, activeAlert.sample(timestamp, 0))
-			activeAlert.State = Firing
+			activeAlert.State = StateFiring
 		}
 
 		vector = append(vector, activeAlert.sample(timestamp, 1))
@@ -189,23 +209,23 @@ func (rule *AlertingRule) Eval(timestamp clientmodel.Timestamp, engine *promql.E
 }
 
 func (rule *AlertingRule) String() string {
-	return fmt.Sprintf("ALERT %s IF %s FOR %s WITH %s", rule.name, rule.Vector, strutil.DurationToString(rule.holdDuration), rule.Labels)
+	return fmt.Sprintf("ALERT %s IF %s FOR %s WITH %s", rule.name, rule.vector, strutil.DurationToString(rule.holdDuration), rule.labels)
 }
 
 // HTMLSnippet returns an HTML snippet representing this alerting rule.
 func (rule *AlertingRule) HTMLSnippet(pathPrefix string) template.HTML {
 	alertMetric := clientmodel.Metric{
-		clientmodel.MetricNameLabel: AlertMetricName,
+		clientmodel.MetricNameLabel: alertMetricName,
-		AlertNameLabel:              clientmodel.LabelValue(rule.name),
+		alertNameLabel:              clientmodel.LabelValue(rule.name),
 	}
 	return template.HTML(fmt.Sprintf(
 		`ALERT <a href="%s">%s</a> IF <a href="%s">%s</a> FOR %s WITH %s`,
 		pathPrefix+strutil.GraphLinkForExpression(alertMetric.String()),
 		rule.name,
-		pathPrefix+strutil.GraphLinkForExpression(rule.Vector.String()),
+		pathPrefix+strutil.GraphLinkForExpression(rule.vector.String()),
-		rule.Vector,
+		rule.vector,
 		strutil.DurationToString(rule.holdDuration),
-		rule.Labels))
+		rule.labels))
 }
 
 // State returns the "maximum" state: firing > pending > inactive.
@@ -213,7 +233,7 @@ func (rule *AlertingRule) State() AlertState {
 	rule.mutex.Lock()
 	defer rule.mutex.Unlock()
 
-	maxState := Inactive
+	maxState := StateInactive
 	for _, activeAlert := range rule.activeAlerts {
 		if activeAlert.State > maxState {
 			maxState = activeAlert.State
@@ -233,17 +253,3 @@ func (rule *AlertingRule) ActiveAlerts() []Alert {
 	}
 	return alerts
 }
-
-// NewAlertingRule constructs a new AlertingRule.
-func NewAlertingRule(name string, vector promql.Expr, holdDuration time.Duration, labels clientmodel.LabelSet, summary string, description string) *AlertingRule {
-	return &AlertingRule{
-		name:         name,
-		Vector:       vector,
-		holdDuration: holdDuration,
-		Labels:       labels,
-		Summary:      summary,
-		Description:  description,
-
-		activeAlerts: map[clientmodel.Fingerprint]*Alert{},
-	}
-}

rules/manager.go

@@ -39,8 +39,8 @@ const (
 	namespace = "prometheus"
 
 	ruleTypeLabel     = "rule_type"
-	alertingRuleType  = "alerting"
+	ruleTypeAlerting  = "alerting"
-	recordingRuleType = "recording"
+	ruleTypeRecording = "recording"
 )
 
 var (
@@ -173,7 +173,7 @@ func (m *Manager) queueAlertNotifications(rule *AlertingRule, timestamp clientmo
 
 	notifications := make(notification.NotificationReqs, 0, len(activeAlerts))
 	for _, aa := range activeAlerts {
-		if aa.State != Firing {
+		if aa.State != StateFiring {
 			// BUG: In the future, make AlertManager support pending alerts?
 			continue
 		}
@@ -205,15 +205,15 @@ func (m *Manager) queueAlertNotifications(rule *AlertingRule, timestamp clientmo
 		}
 
 		notifications = append(notifications, &notification.NotificationReq{
-			Summary:     expand(rule.Summary),
+			Summary:     expand(rule.summary),
-			Description: expand(rule.Description),
+			Description: expand(rule.description),
 			Labels: aa.Labels.Merge(clientmodel.LabelSet{
-				AlertNameLabel: clientmodel.LabelValue(rule.Name()),
+				alertNameLabel: clientmodel.LabelValue(rule.Name()),
 			}),
 			Value:        aa.Value,
 			ActiveSince:  aa.ActiveSince.Time(),
 			RuleString:   rule.String(),
-			GeneratorURL: m.prometheusURL + strings.TrimLeft(strutil.GraphLinkForExpression(rule.Vector.String()), "/"),
+			GeneratorURL: m.prometheusURL + strings.TrimLeft(strutil.GraphLinkForExpression(rule.vector.String()), "/"),
 		})
 	}
 	m.notificationHandler.SubmitReqs(notifications)
@@ -235,7 +235,7 @@ func (m *Manager) runIteration() {
 			defer wg.Done()
 
 			start := time.Now()
-			vector, err := rule.Eval(now, m.queryEngine)
+			vector, err := rule.eval(now, m.queryEngine)
 			duration := time.Since(start)
 
 			if err != nil {
@@ -247,11 +247,11 @@ func (m *Manager) runIteration() {
 			switch r := rule.(type) {
 			case *AlertingRule:
 				m.queueAlertNotifications(r, now)
-				evalDuration.WithLabelValues(alertingRuleType).Observe(
+				evalDuration.WithLabelValues(ruleTypeAlerting).Observe(
 					float64(duration / time.Millisecond),
 				)
 			case *RecordingRule:
-				evalDuration.WithLabelValues(recordingRuleType).Observe(
+				evalDuration.WithLabelValues(ruleTypeRecording).Observe(
 					float64(duration / time.Millisecond),
 				)
 			default:
@@ -319,7 +319,7 @@ func (m *Manager) loadRuleFiles(filenames ...string) error {
 				rule := NewAlertingRule(r.Name, r.Expr, r.Duration, r.Labels, r.Summary, r.Description)
 				m.rules = append(m.rules, rule)
 			case *promql.RecordStmt:
-				rule := &RecordingRule{r.Name, r.Expr, r.Labels}
+				rule := NewRecordingRule(r.Name, r.Expr, r.Labels)
 				m.rules = append(m.rules, rule)
 			default:
 				panic("retrieval.Manager.LoadRuleFiles: unknown statement type")

rules/recording.go

@@ -16,7 +16,6 @@ package rules
 import (
 	"fmt"
 	"html/template"
-	"strings"
 
 	clientmodel "github.com/prometheus/client_golang/model"
 
@@ -31,11 +30,20 @@ type RecordingRule struct {
 	labels clientmodel.LabelSet
 }
 
+// NewRecordingRule returns a new recording rule.
+func NewRecordingRule(name string, vector promql.Expr, labels clientmodel.LabelSet) *RecordingRule {
+	return &RecordingRule{
+		name:   name,
+		vector: vector,
+		labels: labels,
+	}
+}
+
 // Name returns the rule name.
 func (rule RecordingRule) Name() string { return rule.name }
 
-// Eval evaluates the rule and then overrides the metric names and labels accordingly.
+// eval evaluates the rule and then overrides the metric names and labels accordingly.
-func (rule RecordingRule) Eval(timestamp clientmodel.Timestamp, engine *promql.Engine) (promql.Vector, error) {
+func (rule RecordingRule) eval(timestamp clientmodel.Timestamp, engine *promql.Engine) (promql.Vector, error) {
 	query, err := engine.NewInstantQuery(rule.vector.String(), timestamp)
 	if err != nil {
 		return nil, err

rules/rules.go

@@ -27,7 +27,7 @@ type Rule interface {
 	// Name returns the name of the rule.
 	Name() string
 	// Eval evaluates the rule, including any associated recording or alerting actions.
-	Eval(clientmodel.Timestamp, *promql.Engine) (promql.Vector, error)
+	eval(clientmodel.Timestamp, *promql.Engine) (promql.Vector, error)
 	// String returns a human-readable string representation of the rule.
 	String() string
 	// HTMLSnippet returns a human-readable string representation of the rule,

rules/rules_test.go

@@ -186,7 +186,7 @@ func TestAlertingRule(t *testing.T) {
 	for i, expectedLines := range evalOutputs {
 		evalTime := testStartTime.Add(testSampleInterval * time.Duration(i))
 
-		res, err := rule.Eval(evalTime, engine)
+		res, err := rule.eval(evalTime, engine)
 		if err != nil {
 			t.Fatalf("Error during alerting rule evaluation: %s", err)
 		}

web/alerts.go

@@ -63,9 +63,9 @@ func (h *AlertsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	alertStatus := AlertStatus{
 		AlertingRules: alertsSorter.alerts,
 		AlertStateToRowClass: map[rules.AlertState]string{
-			rules.Inactive: "success",
+			rules.StateInactive: "success",
-			rules.Pending:  "warning",
+			rules.StatePending:  "warning",
-			rules.Firing:   "danger",
+			rules.StateFiring:   "danger",
 		},
 	}
 	executeTemplate(w, "alerts", alertStatus, h.PathPrefix)