Implement internal plugin metric collection

pkg/metrics/metrics.go

@@ -0,0 +1,53 @@
+// This package contains internal plugin metrics exposed
+// by Grafana at /api/plugins/alexanderzobnin-zabbix-datasource/metrics
+// in Prometheus format
+
+package metrics
+
+import "github.com/prometheus/client_golang/prometheus"
+
+var (
+	// DataSourceQueryTotal is metric counter for getting total number of data source queries
+	DataSourceQueryTotal *prometheus.CounterVec
+
+	// ZabbixAPIQueryTotal is metric counter for getting total number of zabbix API queries
+	ZabbixAPIQueryTotal *prometheus.CounterVec
+
+	// CacheHitTotal is metric counter for getting total number of cache hits for requests
+	CacheHitTotal *prometheus.CounterVec
+)
+
+func init() {
+	DataSourceQueryTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name:      "datasource_query_total",
+			Help:      "Total number of data source queries.",
+			Namespace: "zabbix_datasource",
+		},
+		[]string{"query_type"},
+	)
+
+	ZabbixAPIQueryTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name:      "zabbix_api_query_total",
+			Help:      "Total number of Zabbix API queries.",
+			Namespace: "zabbix_datasource",
+		},
+		[]string{"method"},
+	)
+
+	CacheHitTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name:      "cache_hit_total",
+			Help:      "Total number of cache hits.",
+			Namespace: "zabbix_datasource",
+		},
+		[]string{"method"},
+	)
+
+	prometheus.MustRegister(
+		DataSourceQueryTotal,
+		ZabbixAPIQueryTotal,
+		CacheHitTotal,
+	)
+}