feat: add labels for cache and puppetdb api usage

Author: fsrv-xyz

cmd/puppet-report-exporter/main.go

@@ -119,9 +119,11 @@ func (app *application) puppetdbLogMetricCollectorBuilder(refreshNotify chan any
 					var report []puppet.ReportLogEntry
 
 					if item := applicationInstance.reportLogCache.Get(node.LatestReportHash); item != nil {
+						go metrics.PuppetDBReportCacheAccess.With(prometheus.Labels{metrics.LabelType: "hit"}).Add(1)
 						report = item.Value()
 					} else {
 						var reportFetchError error
+						go metrics.PuppetDBReportCacheAccess.With(prometheus.Labels{metrics.LabelType: "miss"}).Add(1)
 						report, reportFetchError = app.puppetDb.GetReportHashInfo(node.LatestReportHash)
 						if reportFetchError != nil {
 							continue

internal/metrics/metrics.go

@@ -10,13 +10,17 @@ func init() {
 		NodeCount,
 		NodeLogEntries,
 		PuppetDBReportCacheEntries,
+		PuppetDBReportCacheAccess,
+		PuppetDBQueries,
 	)
 }
 
 const (
 	LabelEnvironment = "environment"
 	LabelNode        = "node"
 	LabelLevel       = "level"
+	LabelType        = "type"
+	LabelEndpoint    = "endpoint"
 )
 
 var (
@@ -54,4 +58,28 @@ var (
 			Help:      "Number of entries in the report log cache",
 		},
 	)
+
+	PuppetDBReportCacheAccess = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "puppet",
+			Subsystem: "report_exporter",
+			Name:      "puppetdb_report_cache_access",
+			Help:      "Number of accesses in the report log cache",
+		},
+		[]string{
+			LabelType,
+		},
+	)
+
+	PuppetDBQueries = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "puppet",
+			Subsystem: "report_exporter",
+			Name:      "puppetdb_queries",
+			Help:      "Number of queries to the PuppetDB API",
+		},
+		[]string{
+			LabelEndpoint,
+		},
+	)
 )

pkg/puppet/api_client.go

@@ -6,6 +6,10 @@ import (
 	"log"
 	"net/http"
 	"net/url"
+
+	"github.com/prometheus/client_golang/prometheus"
+
+	"github.com/bonsai-oss/puppet-report-exporter/internal/metrics"
 )
 
 type ApiClient struct {
@@ -40,6 +44,7 @@ func NewApiClient(options ...ApiClientOption) *ApiClient {
 // GetNodes - Get all nodes from the PuppetDB API
 func (client *ApiClient) GetNodes() ([]Node, error) {
 	var nodes []Node
+	go metrics.PuppetDBQueries.With(prometheus.Labels{metrics.LabelEndpoint: "nodes"}).Inc()
 	response, err := http.Get(client.url.JoinPath("pdb/query/v4/nodes").String())
 	if err != nil {
 		return nil, err
@@ -57,6 +62,7 @@ func (client *ApiClient) GetNodes() ([]Node, error) {
 }
 
 func (client *ApiClient) GetReportHashInfo(hash string) ([]ReportLogEntry, error) {
+	go metrics.PuppetDBQueries.With(prometheus.Labels{metrics.LabelEndpoint: "reports"}).Inc()
 	response, reportFetchError := http.Get(client.url.JoinPath("pdb/query/v4/reports", hash, "logs").String())
 	if reportFetchError != nil {
 		return nil, reportFetchError