Feat/Flaresolverr support (#12)

* new: feat: add flaresolverr support

* chg: feat: add session pool

* chg: fix: deadlock error

* chg: fix: make it work without flaresolverr

api/bludv.go

@@ -44,7 +44,7 @@ func (i *Indexer) HandlerBluDVIndexer(w http.ResponseWriter, r *http.Request) {
 	}
 
 	fmt.Println("URL:>", url)
-	resp, err := http.Get(url)
+	resp, err := i.requester.GetDocument(ctx, url)
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
 		err = json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})
@@ -54,9 +54,9 @@ func (i *Indexer) HandlerBluDVIndexer(w http.ResponseWriter, r *http.Request) {
 		i.metrics.IndexerErrors.WithLabelValues("bludv").Inc()
 		return
 	}
-	defer resp.Body.Close()
+	defer resp.Close()
 
-	doc, err := goquery.NewDocumentFromReader(resp.Body)
+	doc, err := goquery.NewDocumentFromReader(resp)
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
 		err = json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})

api/comando_torrents.go

@@ -60,7 +60,7 @@ func (i *Indexer) HandlerComandoIndexer(w http.ResponseWriter, r *http.Request)
 	}
 
 	fmt.Println("URL:>", url)
-	resp, err := http.Get(url)
+	resp, err := i.requester.GetDocument(ctx, url)
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
 		err = json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})
@@ -70,9 +70,9 @@ func (i *Indexer) HandlerComandoIndexer(w http.ResponseWriter, r *http.Request)
 		i.metrics.IndexerErrors.WithLabelValues("comando").Inc()
 		return
 	}
-	defer resp.Body.Close()
+	defer resp.Close()
 
-	doc, err := goquery.NewDocumentFromReader(resp.Body)
+	doc, err := goquery.NewDocumentFromReader(resp)
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
 		err = json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})
@@ -405,17 +405,18 @@ func getDocument(ctx context.Context, i *Indexer, link string) (*goquery.Documen
 	docCache, err := i.redis.Get(ctx, link)
 	if err == nil {
 		i.metrics.CacheHits.WithLabelValues("document_body").Inc()
+		fmt.Printf("returning from long-lived cache: %s\n", link)
 		return goquery.NewDocumentFromReader(io.NopCloser(bytes.NewReader(docCache)))
 	}
 	defer i.metrics.CacheMisses.WithLabelValues("document_body").Inc()
 
-	resp, err := http.Get(link)
+	resp, err := i.requester.GetDocument(ctx, link)
 	if err != nil {
 		return nil, err
 	}
-	defer resp.Body.Close()
+	defer resp.Close()
 
-	body, err := io.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp)
 	if err != nil {
 		return nil, err
 	}

api/index.go

@@ -7,12 +7,14 @@ import (
 
 	"github.com/felipemarinho97/torrent-indexer/cache"
 	"github.com/felipemarinho97/torrent-indexer/monitoring"
+	"github.com/felipemarinho97/torrent-indexer/requester"
 	"github.com/felipemarinho97/torrent-indexer/schema"
 )
 
 type Indexer struct {
-	redis   *cache.Redis
-	metrics *monitoring.Metrics
+	redis     *cache.Redis
+	metrics   *monitoring.Metrics
+	requester *requester.Requster
 }
 
 type IndexerMeta struct {
@@ -42,10 +44,11 @@ type IndexedTorrent struct {
 	Similarity    float32        `json:"similarity"`
 }
 
-func NewIndexers(redis *cache.Redis, metrics *monitoring.Metrics) *Indexer {
+func NewIndexers(redis *cache.Redis, metrics *monitoring.Metrics, req *requester.Requster) *Indexer {
 	return &Indexer{
-		redis:   redis,
-		metrics: metrics,
+		redis:     redis,
+		metrics:   metrics,
+		requester: req,
 	}
 }
 

cache/redis.go

@@ -10,7 +10,7 @@ import (
 )
 
 var (
-	DefaultExpiration      = 24 * time.Hour * 180 // 180 days
+	DefaultExpiration      = 24 * time.Hour * 7 // 7 days
 	IndexerComandoTorrents = "indexer:comando_torrents"
 )
 

docker-compose.yml

@@ -11,6 +11,7 @@ services:
       - indexer
     environment:
       - REDIS_HOST=redis
+      - FLARESOLVERR_ADDRESS=http://flaresolverr:8191
   
   redis:
     image: redis:alpine

main.go

@@ -1,11 +1,14 @@
 package main
 
 import (
+	"fmt"
 	"net/http"
+	"os"
 
 	handler "github.com/felipemarinho97/torrent-indexer/api"
 	"github.com/felipemarinho97/torrent-indexer/cache"
 	"github.com/felipemarinho97/torrent-indexer/monitoring"
+	"github.com/felipemarinho97/torrent-indexer/requester"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
@@ -13,7 +16,10 @@ func main() {
 	redis := cache.NewRedis()
 	metrics := monitoring.NewMetrics()
 	metrics.Register()
-	indexers := handler.NewIndexers(redis, metrics)
+
+	flaresolverr := requester.NewFlareSolverr(os.Getenv("FLARESOLVERR_ADDRESS"), 60000)
+	req := requester.NewRequester(flaresolverr, redis)
+	indexers := handler.NewIndexers(redis, metrics, req)
 
 	indexerMux := http.NewServeMux()
 	metricsMux := http.NewServeMux()
@@ -31,7 +37,7 @@ func main() {
 			panic(err)
 		}
 	}()
-
+	fmt.Println("Server listening on :7006")
 	err := http.ListenAndServe(":7006", indexerMux)
 	if err != nil {
 		panic(err)

requester/flaresolverr.go

@@ -0,0 +1,230 @@
+package requester
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"sync"
+)
+
+type FlareSolverr struct {
+	url         string
+	maxTimeout  int
+	httpClient  *http.Client
+	sessionPool chan string
+	mu          sync.Mutex
+	initiated   bool
+}
+
+func NewFlareSolverr(url string, timeoutMilli int) *FlareSolverr {
+	poolSize := 5
+	httpClient := &http.Client{}
+	sessionPool := make(chan string, poolSize) // Pool size of 5 sessions
+
+	f := &FlareSolverr{
+		url:         url,
+		maxTimeout:  timeoutMilli,
+		httpClient:  httpClient,
+		sessionPool: sessionPool,
+	}
+
+	err := f.FillSessionPool()
+	if err == nil {
+		f.initiated = true
+	}
+
+	return f
+}
+
+func (f *FlareSolverr) FillSessionPool() error {
+	// Check if the pool is already filled
+	if len(f.sessionPool) == cap(f.sessionPool) {
+		return nil
+	}
+
+	// Pre-initialize the pool with existing sessions
+	sessions, err := f.ListSessions()
+	if err != nil {
+		fmt.Println("Failed to list existing FlareSolverr sessions:", err)
+		return err
+	} else {
+		for _, session := range sessions {
+			// Add available sessions to the pool
+			if len(f.sessionPool) < cap(f.sessionPool) {
+				f.sessionPool <- session
+			}
+		}
+		if len(f.sessionPool) > 0 {
+			fmt.Printf("Added %d FlareSolverr sessions to the pool\n", len(f.sessionPool))
+		}
+	}
+
+	// If fewer than poolSize sessions were found, create new ones to fill the pool
+	for len(f.sessionPool) < cap(f.sessionPool) {
+		f.CreateSession()
+	}
+
+	return nil
+}
+
+func (f *FlareSolverr) CreateSession() string {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	body := map[string]string{"cmd": "sessions.create"}
+	jsonBody, err := json.Marshal(body)
+	if err != nil {
+		return ""
+	}
+
+	req, err := http.NewRequest("POST", fmt.Sprintf("%s/v1", f.url), bytes.NewBuffer(jsonBody))
+	if err != nil {
+		return ""
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := f.httpClient.Do(req)
+	if err != nil {
+		return ""
+	}
+
+	defer resp.Body.Close()
+
+	var sessionResponse map[string]interface{}
+	err = json.NewDecoder(resp.Body).Decode(&sessionResponse)
+	if err != nil {
+		return ""
+	}
+
+	session := sessionResponse["session"].(string)
+	// Add session to the pool
+	f.sessionPool <- session
+
+	fmt.Println("Created new FlareSolverr session:", session)
+	return session
+}
+
+func (f *FlareSolverr) ListSessions() ([]string, error) {
+	body := map[string]string{"cmd": "sessions.list"}
+	jsonBody, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest("POST", fmt.Sprintf("%s/v1", f.url), bytes.NewBuffer(jsonBody))
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := f.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	defer resp.Body.Close()
+
+	var sessionsResponse map[string]interface{}
+	err = json.NewDecoder(resp.Body).Decode(&sessionsResponse)
+	if err != nil {
+		return nil, err
+	}
+
+	sessions := sessionsResponse["sessions"].([]interface{})
+	var sessionIDs []string
+	for _, session := range sessions {
+		sessionIDs = append(sessionIDs, session.(string))
+	}
+
+	return sessionIDs, nil
+}
+
+func (f *FlareSolverr) RetrieveSession() string {
+	// Blocking receive from the session pool.
+	session := <-f.sessionPool
+	return session
+}
+
+type Response struct {
+	Status   string `json:"status"`
+	Message  string `json:"message"`
+	Solution struct {
+		Url     string `json:"url"`
+		Status  int    `json:"status"`
+		Cookies []struct {
+			Domain   string `json:"domain"`
+			Expiry   int    `json:"expiry"`
+			HttpOnly bool   `json:"httpOnly"`
+			Name     string `json:"name"`
+			Path     string `json:"path"`
+			SameSite string `json:"sameSite"`
+			Secure   bool   `json:"secure"`
+			Value    string `json:"value"`
+		} `json:"cookies"`
+		UserAgent string            `json:"userAgent"`
+		Headers   map[string]string `json:"headers"`
+		Response  string            `json:"response"`
+	} `json:"solution"`
+}
+
+func (f *FlareSolverr) Get(url string) (io.ReadCloser, error) {
+	// Check if the FlareSolverr instance was initiated
+	if !f.initiated {
+		return io.NopCloser(bytes.NewReader([]byte(""))), nil
+	}
+
+	// Retrieve session from the pool (blocking if no sessions available)
+	session := f.RetrieveSession()
+
+	// Ensure the session is returned to the pool after the request is done
+	defer func() {
+		f.sessionPool <- session
+	}()
+
+	body := map[string]string{
+		"cmd":        "request.get",
+		"url":        url,
+		"maxTimeout": fmt.Sprintf("%d", f.maxTimeout),
+		"session":    session,
+	}
+	jsonBody, err := json.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+	req, err := http.NewRequest("POST", fmt.Sprintf("%s/v1", f.url), bytes.NewBuffer(jsonBody))
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := f.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// Parse the response
+	var response Response
+	err = json.NewDecoder(resp.Body).Decode(&response)
+	if err != nil {
+		return nil, err
+	}
+
+	// Check if the response was successful
+	if response.Status != "ok" {
+		return nil, fmt.Errorf("failed to get response: %s", response.Message)
+	}
+
+	// Check if "Under attack" is in the response
+	if strings.Contains(response.Solution.Response, "Under attack") {
+		return nil, fmt.Errorf("under attack")
+	}
+
+	// Return the response body
+	return io.NopCloser(bytes.NewReader([]byte(response.Solution.Response))), nil
+}

requester/requester.go

@@ -0,0 +1,93 @@
+package requester
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"regexp"
+	"time"
+
+	"github.com/felipemarinho97/torrent-indexer/cache"
+)
+
+const (
+	shortLivedCacheExpiration = 30 * time.Minute
+	cacheKey                  = "shortLivedCache"
+)
+
+var challangeRegex = regexp.MustCompile(`(?i)(just a moment|cf-chl-bypass|under attack)`)
+
+type Requster struct {
+	fs         *FlareSolverr
+	c          *cache.Redis
+	httpClient *http.Client
+}
+
+func NewRequester(fs *FlareSolverr, c *cache.Redis) *Requster {
+	return &Requster{fs: fs, httpClient: &http.Client{}, c: c}
+}
+
+func (i *Requster) GetDocument(ctx context.Context, url string) (io.ReadCloser, error) {
+	var body io.ReadCloser
+
+	// try request from short-lived cache
+	key := fmt.Sprintf("%s:%s", cacheKey, url)
+	bodyByte, err := i.c.Get(ctx, key)
+	if err == nil {
+		fmt.Printf("returning from short-lived cache: %s\n", url)
+		body = io.NopCloser(bytes.NewReader(bodyByte))
+		return body, nil
+	}
+
+	// try request with plain client
+	resp, err := i.httpClient.Get(url)
+	if err != nil {
+		// try request with flare solverr
+		body, err = i.fs.Get(url)
+		if err != nil {
+			return nil, fmt.Errorf("failed to do request for url %s: %w", url, err)
+		}
+	} else {
+		defer resp.Body.Close()
+		body = resp.Body
+	}
+
+	bodyByte, err = io.ReadAll(body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response body: %w", err)
+	}
+	if hasChallange(bodyByte) {
+		// try request with flare solverr
+		body, err = i.fs.Get(url)
+		if err != nil {
+			return nil, fmt.Errorf("failed to do request for url %s: %w", url, err)
+		}
+		bodyByte, err = io.ReadAll(body)
+		if err != nil {
+			return nil, fmt.Errorf("failed to read response body: %w", err)
+		}
+		fmt.Printf("request served from flaresolverr: %s\n", url)
+	} else {
+		fmt.Printf("request served from plain client: %s\n", url)
+	}
+
+	// save response to cache if it's not a challange and body is not empty
+	if !hasChallange(bodyByte) && len(bodyByte) > 0 {
+		err = i.c.SetWithExpiration(ctx, key, bodyByte, shortLivedCacheExpiration)
+		if err != nil {
+			fmt.Printf("failed to save response to cache: %v\n", err)
+		}
+		fmt.Printf("saved to cache: %s\n", url)
+	} else {
+		return nil, fmt.Errorf("response is a challange")
+	}
+
+	return io.NopCloser(bytes.NewReader(bodyByte)), nil
+}
+
+// hasChallange checks if the body contains a challange by regex matching
+func hasChallange(body []byte) bool {
+	return challangeRegex.Match(body)
+}

scrape/info.go

@@ -52,7 +52,7 @@ func GetLeechsAndSeeds(ctx context.Context, r *cache.Redis, m *monitoring.Metric
 		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)
+		fmt.Println("hash:", infoHash, "get from cache -> leech:", leech, "seed:", seed)
 		return leech, seed, nil
 	}
 
@@ -87,16 +87,18 @@ func GetLeechsAndSeeds(ctx context.Context, r *cache.Redis, m *monitoring.Metric
 	var peer peers
 	for i := 0; i < len(trackers); i++ {
 		select {
+		case <-errChan:
+			// discard error
 		case peer = <-peerChan:
 			err = setPeersToCache(ctx, r, infoHash, peer.Leechers, peer.Seeders)
 			if err != nil {
 				fmt.Println(err)
+			} else {
+				fmt.Println("hash:", infoHash, "get from tracker -> leech:", peer.Leechers, "seed:", peer.Seeders)
 			}
 			return peer.Leechers, peer.Seeders, nil
-		case err := <-errChan:
-			fmt.Println(err)
 		}
 	}
 
-	return 0, 0, fmt.Errorf("unable to get peers from trackers")
+	return 0, 0, fmt.Errorf("unable to get peers from trackers for infohash: %s", infoHash)
 }