Expose captive core version details

ingest/ledgerbackend/captive_core_backend.go

@@ -110,8 +110,9 @@ type CaptiveStellarCore struct {
 	lastLedger         *uint32 // end of current segment if offline, nil if online
 	previousLedgerHash *string
 
-	config            CaptiveCoreConfig
-	stellarCoreClient *stellarcore.Client
+	config             CaptiveCoreConfig
+	stellarCoreClient  *stellarcore.Client
+	captiveCoreVersion string // Updates when captive-core restarts
 }
 
 // CaptiveCoreConfig contains all the parameters required to create a CaptiveStellarCore instance
@@ -211,7 +212,7 @@ func NewCaptive(config CaptiveCoreConfig) (*CaptiveStellarCore, error) {
 			URL: fmt.Sprintf("http://localhost:%d", config.Toml.HTTPPort),
 		}
 	}
-
+	c.setCoreVersion()
 	return c, nil
 }
 
@@ -245,6 +246,21 @@ func (c *CaptiveStellarCore) coreVersionMetric() float64 {
 	return float64(info.Info.ProtocolVersion)
 }
 
+func (c *CaptiveStellarCore) setCoreVersion() {
+	if c.stellarCoreClient == nil {
+		log.WithField("err", errors.New("HTTP stellarCoreClient is not initialized")).Error("cannot fetch captive core version details")
+		return
+	}
+
+	info, err := c.stellarCoreClient.Info(c.config.Context)
+	if err != nil {
+		log.WithField("err", err).Error("cannot fetch captive core version details from /info endpoint")
+		return
+	}
+
+	c.captiveCoreVersion = info.Info.Build
+}
+
 func (c *CaptiveStellarCore) registerMetrics(registry *prometheus.Registry, namespace string) {
 	coreSynced := prometheus.NewGaugeFunc(
 		prometheus.GaugeOpts{