state: add vochain_validator_* metrics (power, score, proposals, votes)

vochain/state/validators.go

@@ -6,13 +6,72 @@ import (
 	"fmt"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/prometheus/client_golang/prometheus"
+	"go.vocdoni.io/dvote/log"
+	"go.vocdoni.io/dvote/metrics"
 	"go.vocdoni.io/dvote/tree/arbo"
 	"go.vocdoni.io/proto/build/go/models"
 	"google.golang.org/protobuf/proto"
 )
 
+var metricValidatorPower = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+	Namespace: "vochain",
+	Name:      "validator_power",
+	Help:      "validator stats",
+}, []string{"address"})
+
+var metricValidatorScore = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+	Namespace: "vochain",
+	Name:      "validator_score",
+	Help:      "validator stats",
+}, []string{"address"})
+
+var metricValidatorProposals = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+	Namespace: "vochain",
+	Name:      "validator_proposals",
+	Help:      "validator stats",
+}, []string{"address"})
+
+var metricValidatorVotes = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+	Namespace: "vochain",
+	Name:      "validator_votes",
+	Help:      "validator stats",
+}, []string{"address"})
+
+func init() {
+	metrics.Register(metricValidatorPower)
+	metrics.Register(metricValidatorScore)
+	metrics.Register(metricValidatorProposals)
+	metrics.Register(metricValidatorVotes)
+}
+
+func setGaugeWithLabel(gv *prometheus.GaugeVec, label string, value float64) {
+	gauge, err := gv.GetMetricWithLabelValues(label)
+	if err != nil {
+		log.Warn(err)
+		return
+	}
+	gauge.Set(value)
+}
+
+func metricsUpdateValidator(validator *models.Validator) {
+	label := fmt.Sprintf("%x", validator.GetAddress())
+	setGaugeWithLabel(metricValidatorPower, label, float64(validator.GetPower()))
+	setGaugeWithLabel(metricValidatorScore, label, float64(validator.GetScore()))
+	setGaugeWithLabel(metricValidatorProposals, label, float64(validator.GetProposals()))
+	setGaugeWithLabel(metricValidatorVotes, label, float64(validator.GetVotes()))
+}
+
+func metricsDeleteValidator(label string) {
+	metricValidatorPower.DeleteLabelValues(label)
+	metricValidatorScore.DeleteLabelValues(label)
+	metricValidatorProposals.DeleteLabelValues(label)
+	metricValidatorVotes.DeleteLabelValues(label)
+}
+
 // AddValidator adds a tendemint validator. If it exists, it will be updated.
 func (v *State) AddValidator(validator *models.Validator) error {
+	defer metricsUpdateValidator(validator)
 	v.tx.Lock()
 	defer v.tx.Unlock()
 	validatorBytes, err := proto.Marshal(validator)
@@ -24,6 +83,7 @@ func (v *State) AddValidator(validator *models.Validator) error {
 
 // RemoveValidator removes a tendermint validator identified by its address
 func (v *State) RemoveValidator(address []byte) error {
+	defer metricsDeleteValidator(fmt.Sprintf("%x", address))
 	v.tx.Lock()
 	defer v.tx.Unlock()
 	validators, err := v.tx.SubTree(StateTreeCfg(TreeValidators))