[#1154] ir: Add info metric

Signed-off-by: Alexander Chuprov <a.chuprov@yadro.com>

internal/metrics/application.go

@@ -0,0 +1,21 @@
+package metrics
+
+import (
+	"git.frostfs.info/TrueCloudLab/frostfs-observability/metrics"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type ApplicationInfo struct {
+	versionValue *prometheus.GaugeVec
+}
+
+func NewApplicationInfo(version string) *ApplicationInfo {
+	appInfo := &ApplicationInfo{
+		versionValue: metrics.NewGaugeVec(prometheus.GaugeOpts{
+			Name: "app_info",
+			Help: "General information about the application.",
+		}, []string{"version"}),
+	}
+	appInfo.versionValue.With(prometheus.Labels{"version": version})
+	return appInfo
+}

internal/metrics/innerring.go

@@ -4,6 +4,7 @@ import (
 	"strconv"
 	"time"
 
+	"git.frostfs.info/TrueCloudLab/frostfs-node/misc"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
 	"git.frostfs.info/TrueCloudLab/frostfs-observability/metrics"
 	"github.com/prometheus/client_golang/prometheus"
@@ -16,6 +17,7 @@ type InnerRingServiceMetrics struct {
 	eventDuration     *prometheus.HistogramVec
 	morphCacheMetrics *morphCacheMetrics
 	logMetrics        logger.LogMetrics
+	appInfo           *ApplicationInfo
 }
 
 // NewInnerRingMetrics returns new instance of metrics collectors for inner ring.
@@ -46,6 +48,7 @@ func NewInnerRingMetrics() *InnerRingServiceMetrics {
 		health:            health,
 		eventDuration:     eventDuration,
 		morphCacheMetrics: newMorphCacheMetrics(innerRingNamespace),
+		appInfo:           NewApplicationInfo(misc.Version),
 		logMetrics:        logger.NewLogMetrics(innerRingNamespace),
 	}
 }

internal/metrics/node.go

@@ -1,6 +1,7 @@
 package metrics
 
 import (
+	"git.frostfs.info/TrueCloudLab/frostfs-node/misc"
 	morphmetrics "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/metrics"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
 	"git.frostfs.info/TrueCloudLab/frostfs-observability/metrics"
@@ -24,6 +25,7 @@ type NodeMetrics struct {
 	morphClient   *morphClientMetrics
 	morphCache    *morphCacheMetrics
 	log           logger.LogMetrics
+	appInfo       *ApplicationInfo
 }
 
 func NewNodeMetrics() *NodeMetrics {
@@ -49,6 +51,7 @@ func NewNodeMetrics() *NodeMetrics {
 		morphClient:  newMorphClientMetrics(),
 		morphCache:   newMorphCacheMetrics(namespace),
 		log:          logger.NewLogMetrics(namespace),
+		appInfo:      NewApplicationInfo(misc.Version),
 	}
 }