Remaining points

- subSystem configured in one place
- poolLabel configured in one place
- float64 use in the json decoding

collectors/pool_usage.go

@@ -48,53 +48,57 @@ type PoolUsageCollector struct {
 // NewPoolUsageCollector creates a new instance of PoolUsageCollector and returns
 // its reference.
 func NewPoolUsageCollector(conn Conn) *PoolUsageCollector {
+	var (
+		subSystem = "pool"
+		poolLabel = []string{"pool"}
+	)
 	return &PoolUsageCollector{
 		conn: conn,
 
 		UsedBytes: prometheus.NewGaugeVec(
 			prometheus.GaugeOpts{
 				Namespace: cephNamespace,
-				Subsystem: "pool",
+				Subsystem: subSystem,
 				Name:      "used_bytes",
 				Help:      "Capacity of the pool that is currently under use",
 			},
-			[]string{"pool"},
+			poolLabel,
 		),
 		MaxAvail: prometheus.NewGaugeVec(
 			prometheus.GaugeOpts{
 				Namespace: cephNamespace,
-				Subsystem: "pool",
+				Subsystem: subSystem,
 				Name:      "available_bytes",
 				Help:      "Free space for this ceph pool",
 			},
-			[]string{"pool"},
+			poolLabel,
 		),
 		Objects: prometheus.NewGaugeVec(
 			prometheus.GaugeOpts{
 				Namespace: cephNamespace,
-				Subsystem: "pool",
+				Subsystem: subSystem,
 				Name:      "objects_total",
 				Help:      "Total no. of objects allocated within the pool",
 			},
-			[]string{"pool"},
+			poolLabel,
 		),
 		ReadIO: prometheus.NewCounterVec(
 			prometheus.CounterOpts{
 				Namespace: cephNamespace,
-				Subsystem: "pool",
+				Subsystem: subSystem,
 				Name:      "read_total",
 				Help:      "Total read i/o calls the pool has been subject to",
 			},
-			[]string{"pool"},
+			poolLabel,
 		),
 		WriteIO: prometheus.NewCounterVec(
 			prometheus.CounterOpts{
 				Namespace: cephNamespace,
-				Subsystem: "pool",
+				Subsystem: subSystem,
 				Name:      "write_total",
 				Help:      "Total write i/o calls the pool has been subject to",
 			},
-			[]string{"pool"},
+			poolLabel,
 		),
 	}
 }
@@ -114,11 +118,11 @@ type cephPoolStats struct {
 		Name  string `json:"name"`
 		ID    int    `json:"id"`
 		Stats struct {
-			BytesUsed json.Number `json:"bytes_used"`
-			MaxAvail  float64     `json:"max_avail"`
-			Objects   json.Number `json:"objects"`
-			Read      json.Number `json:"rd"`
-			Write     json.Number `json:"wr"`
+			BytesUsed float64 `json:"bytes_used"`
+			MaxAvail  float64 `json:"max_avail"`
+			Objects   float64 `json:"objects"`
+			Read      float64 `json:"rd"`
+			Write     float64 `json:"wr"`
 		} `json:"stats"`
 	} `json:"pools"`
 }
@@ -140,33 +144,11 @@ func (p *PoolUsageCollector) collect() error {
 	}
 
 	for _, pool := range stats.Pools {
-		var bytesUsed, objects, read, write float64
-
-		bytesUsed, err = pool.Stats.BytesUsed.Float64()
-		if err != nil {
-			log.Printf("[ERROR] cannot extract used bytes for pool %q: %s", pool.Name, err)
-		}
-
-		objects, err := pool.Stats.Objects.Float64()
-		if err != nil {
-			log.Printf("[ERROR] cannot extract total objects for pool %q: %s", pool.Name, err)
-		}
-
-		read, err = pool.Stats.Read.Float64()
-		if err != nil {
-			log.Printf("[ERROR] cannot extract read stats for pool %q: %s", pool.Name, err)
-		}
-
-		write, err = pool.Stats.Write.Float64()
-		if err != nil {
-			log.Printf("[ERROR] cannot extract write stats for pool %q: %s", pool.Name, err)
-		}
-
-		p.UsedBytes.WithLabelValues(pool.Name).Set(bytesUsed)
+		p.UsedBytes.WithLabelValues(pool.Name).Set(pool.Stats.BytesUsed)
 		p.MaxAvail.WithLabelValues(pool.Name).Set(pool.Stats.MaxAvail)
-		p.Objects.WithLabelValues(pool.Name).Set(objects)
-		p.ReadIO.WithLabelValues(pool.Name).Set(read)
-		p.WriteIO.WithLabelValues(pool.Name).Set(write)
+		p.Objects.WithLabelValues(pool.Name).Set(pool.Stats.Objects)
+		p.ReadIO.WithLabelValues(pool.Name).Set(pool.Stats.Read)
+		p.WriteIO.WithLabelValues(pool.Name).Set(pool.Stats.Write)
 	}
 
 	return nil