new: feat: add metrics endpoint and prometheus monitoring

api/bludv.go

@@ -22,6 +22,12 @@ var bludv = IndexerMeta{
 }
 
 func (i *Indexer) HandlerBluDVIndexer(w http.ResponseWriter, r *http.Request) {
+	start := time.Now()
+	defer func() {
+		i.metrics.IndexerDuration.WithLabelValues("bludv").Observe(time.Since(start).Seconds())
+		i.metrics.IndexerRequests.WithLabelValues("bludv").Inc()
+	}()
+
 	ctx := r.Context()
 	// supported query params: q, season, episode
 	q := r.URL.Query().Get("q")
@@ -38,6 +44,7 @@ func (i *Indexer) HandlerBluDVIndexer(w http.ResponseWriter, r *http.Request) {
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
 		json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})
+		i.metrics.IndexerErrors.WithLabelValues("bludv").Inc()
 		return
 	}
 	defer resp.Body.Close()
@@ -46,6 +53,7 @@ func (i *Indexer) HandlerBluDVIndexer(w http.ResponseWriter, r *http.Request) {
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
 		json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})
+		i.metrics.IndexerErrors.WithLabelValues("bludv").Inc()
 		return
 	}
 
@@ -174,7 +182,7 @@ func getTorrentsBluDV(ctx context.Context, i *Indexer, link string) ([]IndexedTo
 				magnetAudio = append(magnetAudio, audio...)
 			}
 
-			peer, seed, err := goscrape.GetLeechsAndSeeds(ctx, i.redis, infoHash, trackers)
+			peer, seed, err := goscrape.GetLeechsAndSeeds(ctx, i.redis, i.metrics, infoHash, trackers)
 			if err != nil {
 				fmt.Println(err)
 			}

api/comando_torrents.go

@@ -39,6 +39,12 @@ var replacer = strings.NewReplacer(
 )
 
 func (i *Indexer) HandlerComandoIndexer(w http.ResponseWriter, r *http.Request) {
+	start := time.Now()
+	defer func() {
+		i.metrics.IndexerDuration.WithLabelValues("comando").Observe(time.Since(start).Seconds())
+		i.metrics.IndexerRequests.WithLabelValues("comando").Inc()
+	}()
+
 	ctx := r.Context()
 	// supported query params: q, season, episode
 	q := r.URL.Query().Get("q")
@@ -55,6 +61,7 @@ func (i *Indexer) HandlerComandoIndexer(w http.ResponseWriter, r *http.Request)
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
 		json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})
+		i.metrics.IndexerErrors.WithLabelValues("comando").Inc()
 		return
 	}
 	defer resp.Body.Close()
@@ -63,6 +70,7 @@ func (i *Indexer) HandlerComandoIndexer(w http.ResponseWriter, r *http.Request)
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
 		json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})
+		i.metrics.IndexerErrors.WithLabelValues("comando").Inc()
 		return
 	}
 
@@ -206,7 +214,7 @@ func getTorrents(ctx context.Context, i *Indexer, link string) ([]IndexedTorrent
 				magnetAudio = append(magnetAudio, audio...)
 			}
 
-			peer, seed, err := goscrape.GetLeechsAndSeeds(ctx, i.redis, infoHash, trackers)
+			peer, seed, err := goscrape.GetLeechsAndSeeds(ctx, i.redis, i.metrics, infoHash, trackers)
 			if err != nil {
 				fmt.Println(err)
 			}
@@ -365,8 +373,10 @@ func getDocument(ctx context.Context, i *Indexer, link string) (*goquery.Documen
 	// try to get from redis first
 	docCache, err := i.redis.Get(ctx, link)
 	if err == nil {
+		i.metrics.CacheHits.WithLabelValues("document_body").Inc()
 		return goquery.NewDocumentFromReader(ioutil.NopCloser(bytes.NewReader(docCache)))
 	}
+	defer i.metrics.CacheMisses.WithLabelValues("document_body").Inc()
 
 	resp, err := http.Get(link)
 	if err != nil {

api/index.go

@@ -6,11 +6,13 @@ import (
 	"time"
 
 	"github.com/felipemarinho97/torrent-indexer/cache"
+	"github.com/felipemarinho97/torrent-indexer/monitoring"
 	"github.com/felipemarinho97/torrent-indexer/schema"
 )
 
 type Indexer struct {
-	redis *cache.Redis
+	redis   *cache.Redis
+	metrics *monitoring.Metrics
 }
 
 type IndexerMeta struct {
@@ -39,9 +41,10 @@ type IndexedTorrent struct {
 	SeedCount     int            `json:"seed_count"`
 }
 
-func NewIndexers(redis *cache.Redis) *Indexer {
+func NewIndexers(redis *cache.Redis, metrics *monitoring.Metrics) *Indexer {
 	return &Indexer{
-		redis: redis,
+		redis:   redis,
+		metrics: metrics,
 	}
 }
 

go.mod

@@ -1,14 +1,23 @@
 module github.com/felipemarinho97/torrent-indexer
 
-go 1.18
+go 1.21
 
-require github.com/redis/go-redis/v9 v9.2.0
+require github.com/redis/go-redis/v9 v9.5.1
 
 require (
-	github.com/andybalholm/cascadia v1.3.1 // indirect
+	github.com/andybalholm/cascadia v1.3.2 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
-	golang.org/x/net v0.7.0 // indirect
+	github.com/prometheus/client_model v0.6.0 // indirect
+	github.com/prometheus/common v0.50.0 // indirect
+	github.com/prometheus/procfs v0.13.0 // indirect
+	golang.org/x/net v0.22.0 // indirect
+	golang.org/x/sys v0.18.0 // indirect
+	google.golang.org/protobuf v1.33.0 // indirect
 )
 
-require github.com/PuerkitoBio/goquery v1.8.1
+require (
+	github.com/PuerkitoBio/goquery v1.9.1
+	github.com/prometheus/client_golang v1.19.0
+)

go.sum

@@ -1,7 +1,9 @@
-github.com/PuerkitoBio/goquery v1.8.1 h1:uQxhNlArOIdbrH1tr0UXwdVFgDcZDrZVdcpygAcwmWM=
+github.com/PuerkitoBio/goquery v1.9.1 h1:mTL6XjbJTZdpfL+Gwl5U2h1l9yEkJjhmlTeV9VPW7UI=
-github.com/PuerkitoBio/goquery v1.8.1/go.mod h1:Q8ICL1kNUJ2sXGoAhPGUdYDJvgQgHzJsnnd3H7Ho5jQ=
+github.com/PuerkitoBio/goquery v1.9.1/go.mod h1:cW1n6TmIMDoORQU5IU/P1T3tGFunOeXEpGP2WHRwkbY=
-github.com/andybalholm/cascadia v1.3.1 h1:nhxRkql1kdYCc8Snf7D5/D3spOX+dBgjA6u8x004T2c=
+github.com/andybalholm/cascadia v1.3.2 h1:3Xi6Dw5lHF15JtdcmAHD3i1+T8plmv7BQ/nsViSLyss=
-github.com/andybalholm/cascadia v1.3.1/go.mod h1:R4bJ1UQfqADjvDa4P6HZHLh/3OxWWEqc0Sk8XGwHqvA=
+github.com/andybalholm/cascadia v1.3.2/go.mod h1:7gtRlve5FxPPgIgX36uWBX58OdBsSS6lUvCFb+h7KvU=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/bsm/ginkgo/v2 v2.12.0 h1:Ny8MWAHyOepLGlLKYmXG4IEkioBysk6GpaRTLC8zwWs=
 github.com/bsm/ginkgo/v2 v2.12.0/go.mod h1:SwYbGRRDovPVboqFv0tPTcG1sN61LM1Z4ARdbAV9g4c=
 github.com/bsm/gomega v1.27.10 h1:yeMWxP2pV2fG3FgAODIY8EiRE3dy0aeFYt4l7wh6yKA=
@@ -10,36 +12,55 @@ github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj
 github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
 github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
-github.com/redis/go-redis/v9 v9.2.0 h1:zwMdX0A4eVzse46YN18QhuDiM4uf3JmkOB4VZrdt5uI=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
-github.com/redis/go-redis/v9 v9.2.0/go.mod h1:hdY0cQFCN4fnSYT6TkisLufl/4W5UIXyv0b/CLO2V2M=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/prometheus/client_golang v1.19.0 h1:ygXvpU1AoN1MhdzckN+PyD9QJOSD4x7kmXYlnfbA6JU=
+github.com/prometheus/client_golang v1.19.0/go.mod h1:ZRM9uEAypZakd+q/x7+gmsvXdURP+DABIEIjnmDdp+k=
+github.com/prometheus/client_model v0.6.0 h1:k1v3CzpSRUTrKMppY35TLwPvxHqBu0bYgxZzqGIgaos=
+github.com/prometheus/client_model v0.6.0/go.mod h1:NTQHnmxFpouOD0DpvP4XujX3CdOAGQPoaGhyTchlyt8=
+github.com/prometheus/common v0.50.0 h1:YSZE6aa9+luNa2da6/Tik0q0A5AbR+U003TItK57CPQ=
+github.com/prometheus/common v0.50.0/go.mod h1:wHFBCEVWVmHMUpg7pYcOm2QUR/ocQdYSJVQJKnHc3xQ=
+github.com/prometheus/procfs v0.13.0 h1:GqzLlQyfsPbaEHaQkO7tbDlriv/4o5Hudv6OXHGKX7o=
+github.com/prometheus/procfs v0.13.0/go.mod h1:cd4PFCR54QLnGKPaKGA6l+cfuNXtht43ZKY6tow0Y1g=
+github.com/redis/go-redis/v9 v9.5.1 h1:H1X4D3yHPaYrkL5X06Wh6xNVM/pX0Ft4RV0vMGvLBh8=
+github.com/redis/go-redis/v9 v9.5.1/go.mod h1:hdY0cQFCN4fnSYT6TkisLufl/4W5UIXyv0b/CLO2V2M=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20210916014120-12bc252f5db8/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/net v0.7.0 h1:rJrUqqhjsgNp7KqAIc25s9pZnjU7TUcSY7HcVZjdn1g=
+golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
-golang.org/x/net v0.7.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
+golang.org/x/net v0.9.0/go.mod h1:d48xBJpPfHeWQsugry2m+kC02ZBRGRgulfHnEXEuWns=
+golang.org/x/net v0.22.0 h1:9sGLhx7iRIHEiX0oAJ3MRZMUCElJgy7Br1nO+AMN3Tc=
+golang.org/x/net v0.22.0/go.mod h1:JKghWKKOSdJwpW2GEx0Ja7fmaKnMsbu+MWVZTokSYmg=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
+golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
+golang.org/x/term v0.7.0/go.mod h1:P32HKFT3hSsZrRxla30E9HqToFYAQPCMs/zFMBUFqPY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
+golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/protobuf v1.33.0 h1:uNO2rsAINq/JlFpSdYEKIZ0uKD/R9cpdv0T+yoGwGmI=
+google.golang.org/protobuf v1.33.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=

main.go

@@ -5,17 +5,33 @@ import (
 
 	handler "github.com/felipemarinho97/torrent-indexer/api"
 	"github.com/felipemarinho97/torrent-indexer/cache"
+	"github.com/felipemarinho97/torrent-indexer/monitoring"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 func main() {
 	redis := cache.NewRedis()
-	indexers := handler.NewIndexers(redis)
+	metrics := monitoring.NewMetrics()
+	metrics.Register()
+	indexers := handler.NewIndexers(redis, metrics)
 
-	http.HandleFunc("/", handler.HandlerIndex)
+	indexerMux := http.NewServeMux()
-	http.HandleFunc("/indexers/comando_torrents", indexers.HandlerComandoIndexer)
+	metricsMux := http.NewServeMux()
-	http.HandleFunc("/indexers/bludv", indexers.HandlerBluDVIndexer)
 
-	err := http.ListenAndServe(":7006", nil)
+	indexerMux.HandleFunc("/", handler.HandlerIndex)
+	indexerMux.HandleFunc("/indexers/comando_torrents", indexers.HandlerComandoIndexer)
+	indexerMux.HandleFunc("/indexers/bludv", indexers.HandlerBluDVIndexer)
+
+	metricsMux.Handle("/metrics", promhttp.Handler())
+
+	go func() {
+		err := http.ListenAndServe(":8081", metricsMux)
+		if err != nil {
+			panic(err)
+		}
+	}()
+
+	err := http.ListenAndServe(":7006", indexerMux)
 	if err != nil {
 		panic(err)
 	}

monitoring/prometheus.go

@@ -0,0 +1,47 @@
+package monitoring
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type Metrics struct {
+	IndexerDuration *prometheus.HistogramVec
+	IndexerErrors   *prometheus.CounterVec
+	IndexerRequests *prometheus.CounterVec
+	CacheHits       *prometheus.CounterVec
+	CacheMisses     *prometheus.CounterVec
+}
+
+func NewMetrics() *Metrics {
+	return &Metrics{
+		IndexerDuration: prometheus.NewHistogramVec(prometheus.HistogramOpts{
+			Name:    "indexer_duration_seconds",
+			Help:    "Duration of indexer requests",
+			Buckets: []float64{0.1, 0.5, 1, 2, 5, 10, 20, 30},
+		}, []string{"indexer"}),
+		IndexerErrors: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "indexer_errors_total",
+			Help: "Number of indexer errors",
+		}, []string{"indexer"}),
+		IndexerRequests: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "indexer_requests_total",
+			Help: "Number of indexer requests",
+		}, []string{"indexer"}),
+		CacheHits: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "cache_hits_total",
+			Help: "Number of cache hits",
+		}, []string{"cache"}),
+		CacheMisses: prometheus.NewCounterVec(prometheus.CounterOpts{
+			Name: "cache_misses_total",
+			Help: "Number of cache misses",
+		}, []string{"cache"}),
+	}
+}
+
+func (m *Metrics) Register() {
+	prometheus.MustRegister(m.IndexerDuration)
+	prometheus.MustRegister(m.IndexerErrors)
+	prometheus.MustRegister(m.IndexerRequests)
+	prometheus.MustRegister(m.CacheHits)
+	prometheus.MustRegister(m.CacheMisses)
+}

scrape/info.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/felipemarinho97/torrent-indexer/cache"
+	"github.com/felipemarinho97/torrent-indexer/monitoring"
 )
 
 type peers struct {
@@ -44,11 +45,13 @@ func setPeersToCache(ctx context.Context, r *cache.Redis, infoHash string, peer,
 	return nil
 }
 
-func GetLeechsAndSeeds(ctx context.Context, r *cache.Redis, infoHash string, trackers []string) (int, int, error) {
+func GetLeechsAndSeeds(ctx context.Context, r *cache.Redis, m *monitoring.Metrics, infoHash string, trackers []string) (int, int, error) {
 	leech, seed, err := getPeersFromCache(ctx, r, infoHash)
 	if err != nil {
+		m.CacheHits.WithLabelValues("peers").Inc()
 		fmt.Println("unable to get peers from cache for infohash:", infoHash)
 	} else {
+		m.CacheMisses.WithLabelValues("peers").Inc()
 		fmt.Println("get from cache> leech:", leech, "seed:", seed)
 		return leech, seed, nil
 	}