Resources allocation improvement.

README.md

@@ -30,6 +30,7 @@ I wanted to monitor the queries and responses of our graphql endpoint. Still, we
 | security   | Blocking schema introspection                                         |
 | security   | Rate limiting queries based on user role                              |
 | security   | Blocking mutations in read-only mode                                  |
+| security   | Allow access only to listed URLs                                      |
 
 
 ### Configuration
@@ -49,6 +50,7 @@ I wanted to monitor the queries and responses of our graphql endpoint. Still, we
 | `BLOCK_SCHEMA_INTROSPECTION`| Blocks the schema introspection       | `false`                    |
 | `ENABLE_ACCESS_LOG`       | Enable the access log                   | `false`                    |
 | `READ_ONLY_MODE`          | Enable the read only mode               | `false`                    |
+| `ALLOWED_URLS`              | Allow access only to certain URLs       | `/v1/graphql,/v1/version`  |
 
 
 ### Caching
@@ -101,6 +103,11 @@ If rate limit has been reached - the proxy will return `429 Too Many Requests` e
 
 You can enable the read-only mode by setting the `READ_ONLY_MODE` environment variable to `true` - which will block all the `mutation` queries.
 
+### Allowing access to listed URLs
+
+You can allow access only to certain URLs by setting the `ALLOWED_URLS` environment variable to a comma-separated list of URLs. If enabled - other URLs will return `403 Forbidden` error and request will **not** reach the proxied service.
+
+
 ### Monitoring endpoint
 
 Example metrics produced by the proxy:

cache.go

@@ -4,9 +4,9 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/akyoto/cache"
 	fiber "github.com/gofiber/fiber/v2"
 	"github.com/gookit/goutil/strutil"
+	libpack_cache "github.com/lukaszraczylo/graphql-monitoring-proxy/cache"
 )
 
 func calculateHash(c *fiber.Ctx) string {
@@ -14,19 +14,14 @@ func calculateHash(c *fiber.Ctx) string {
 }
 
 func enableCache() {
-	var err error
-	cfg.Cache.CacheClient = cache.New(time.Duration(cfg.Cache.CacheTTL) * time.Second * 2)
-	if err != nil {
-		cfg.Logger.Critical("Can't create cache client", map[string]interface{}{"error": err.Error()})
-		panic(err)
-	}
+	cfg.Cache.CacheClient = libpack_cache.New(time.Duration(cfg.Cache.CacheTTL) * time.Second * 2)
 }
 
 func cacheLookup(hash string) []byte {
 	if cfg.Cache.CacheClient != nil {
 		obj, found := cfg.Cache.CacheClient.Get(hash)
 		if found {
-			return obj.([]byte)
+			return obj
 		}
 	}
 	return nil

cache/cache.go

@@ -0,0 +1,92 @@
+package libpack_cache
+
+import (
+	"sync"
+	"time"
+)
+
+type CacheEntry struct {
+	Value     []byte
+	ExpiresAt time.Time
+}
+
+type Cache struct {
+	sync.RWMutex
+	entries   map[string]CacheEntry
+	globalTTL time.Duration
+}
+
+func New(globalTTL time.Duration) *Cache {
+	cache := &Cache{
+		entries:   make(map[string]CacheEntry),
+		globalTTL: globalTTL,
+	}
+
+	// Start the cache cleanup.
+	go cache.cleanupRoutine(globalTTL)
+	return cache
+}
+
+func (c *Cache) cleanupRoutine(globalTTL time.Duration) {
+	ticker := time.NewTicker(globalTTL / 2)
+	defer ticker.Stop()
+
+	for range ticker.C {
+		c.CleanExpiredEntries()
+	}
+}
+
+func (c *Cache) Set(key string, value []byte, ttl time.Duration) {
+	c.Lock()
+	defer c.Unlock()
+
+	now := time.Now()
+	expiresAt := now.Add(ttl)
+	if expiresAt.After(now.Add(c.globalTTL)) {
+		expiresAt = now.Add(c.globalTTL)
+	}
+
+	c.entries[key] = CacheEntry{
+		Value:     value,
+		ExpiresAt: expiresAt,
+	}
+}
+
+func (c *Cache) Get(key string) ([]byte, bool) {
+	c.RLock()
+	defer c.RUnlock()
+
+	entry, ok := c.entries[key]
+	if !ok || entry.ExpiresAt.Before(time.Now()) {
+		return nil, false
+	}
+
+	return entry.Value, true
+}
+
+func (c *Cache) Delete(key string) {
+	c.Lock()
+	defer c.Unlock()
+
+	delete(c.entries, key)
+}
+
+func (c *Cache) CleanExpiredEntries() {
+	now := time.Now()
+	toDelete := make([]string, 0)
+
+	c.RLock()
+	for key, entry := range c.entries {
+		if entry.ExpiresAt.Before(now) {
+			toDelete = append(toDelete, key)
+		}
+	}
+	c.RUnlock()
+
+	// Separate the deletion to its own critical section to reduce lock contention.
+	c.Lock()
+	for _, key := range toDelete {
+		delete(c.entries, key)
+	}
+	c.Unlock()
+}

go.mod

@@ -4,20 +4,21 @@ go 1.21
 
 require (
 	github.com/VictoriaMetrics/metrics v1.24.0
-	github.com/akyoto/cache v1.0.6
 	github.com/buger/jsonparser v1.1.1
 	github.com/gofiber/fiber/v2 v2.49.2
-	github.com/gookit/goutil v0.6.12
+	github.com/gookit/goutil v0.6.13
 	github.com/graphql-go/graphql v0.8.1
 	github.com/json-iterator/go v1.1.12
 	github.com/lukaszraczylo/ask v0.0.0-20230927103145-2ff1123b4415
 	github.com/lukaszraczylo/go-ratecounter v0.1.8
-	github.com/lukaszraczylo/go-simple-graphql v1.1.31
+	github.com/lukaszraczylo/go-simple-graphql v1.1.32
 	github.com/rs/zerolog v1.31.0
 	github.com/stretchr/testify v1.8.4
+	github.com/valyala/fasthttp v1.50.0
 )
 
 require (
+	github.com/akyoto/cache v1.0.6 // indirect
 	github.com/andybalholm/brotli v1.0.5 // indirect
 	github.com/avast/retry-go/v4 v4.5.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
@@ -34,7 +35,6 @@ require (
 	github.com/rivo/uniseg v0.4.4 // indirect
 	github.com/rogpeppe/go-internal v1.11.0 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
-	github.com/valyala/fasthttp v1.50.0 // indirect
 	github.com/valyala/fastrand v1.1.0 // indirect
 	github.com/valyala/histogram v1.2.0 // indirect
 	github.com/valyala/tcplisten v1.0.0 // indirect

go.sum

@@ -21,8 +21,8 @@ github.com/google/uuid v1.3.1 h1:KjJaJ9iWZ3jOFZIf1Lqf4laDRCasjl0BCmnEGxkdLb4=
 github.com/google/uuid v1.3.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gookit/color v1.5.4 h1:FZmqs7XOyGgCAxmWyPslpiok1k05wmY3SJTytgvYFs0=
 github.com/gookit/color v1.5.4/go.mod h1:pZJOeOS8DM43rXbp4AZo1n9zCU2qjpcRko0b6/QJi9w=
-github.com/gookit/goutil v0.6.12 h1:73vPUcTtVGXbhSzBOFcnSB1aJl7Jq9np3RAE50yIDZc=
-github.com/gookit/goutil v0.6.12/go.mod h1:g6krlFib8xSe3G1h02IETowOtrUGpAmetT8IevDpvpM=
+github.com/gookit/goutil v0.6.13 h1:ttg7yMda6Q9fkE4P+YTwozd2wH1Le0CQldTAtOFBr7o=
+github.com/gookit/goutil v0.6.13/go.mod h1:YyDBddefmjS+mU2PDPgCcjVzTDM5WgExiDv5ZA/b8I8=
 github.com/graphql-go/graphql v0.8.1 h1:p7/Ou/WpmulocJeEx7wjQy611rtXGQaAcXGqanuMMgc=
 github.com/graphql-go/graphql v0.8.1/go.mod h1:nKiHzRM0qopJEwCITUuIsxk9PlVlwIiiI8pnJEhordQ=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
@@ -40,8 +40,8 @@ github.com/lukaszraczylo/ask v0.0.0-20230927103145-2ff1123b4415 h1:lvI8Wlbg4PxkR
 github.com/lukaszraczylo/ask v0.0.0-20230927103145-2ff1123b4415/go.mod h1:M+UVdyqZs++xtEPrascaVmZdOMhCnxjZ2SgH+xHpR0c=
 github.com/lukaszraczylo/go-ratecounter v0.1.8 h1:ZYm6Wkn58ZAlFWRmC7PaD4oAYHWcu8/0MUDWGe3PnJQ=
 github.com/lukaszraczylo/go-ratecounter v0.1.8/go.mod h1:TqXEOCtFJStk1i0tkipprv1kiDHGon1MVUisjSTBSKM=
-github.com/lukaszraczylo/go-simple-graphql v1.1.31 h1:UA3f8M1cV+XnO8UZlAqveW0qF/2NN512eB/gRqe+BHs=
-github.com/lukaszraczylo/go-simple-graphql v1.1.31/go.mod h1:MyftQ8jTdtkYImPXJpHoxz6+E53Ydv+7q9+Jr+eT8WU=
+github.com/lukaszraczylo/go-simple-graphql v1.1.32 h1:udiz2hnLNO2b/hc9Z0xcjYt+HcFbChQQuIY4HZmky80=
+github.com/lukaszraczylo/go-simple-graphql v1.1.32/go.mod h1:c1nN/qtjsvpqpkBFsnBCYCDLdLMuWzy/zxeJzTjm5qg=
 github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
 github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=

main.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"strings"
+
 	"github.com/gookit/goutil/envutil"
 	graphql "github.com/lukaszraczylo/go-simple-graphql"
 	libpack_config "github.com/lukaszraczylo/graphql-monitoring-proxy/config"
@@ -33,6 +35,14 @@ func parseConfig() {
 	c.Client.GQLClient.SetEndpoint(c.Server.HostGraphQL)
 	c.Server.AccessLog = envutil.GetBool("ENABLE_ACCESS_LOG", false)
 	c.Server.ReadOnlyMode = envutil.GetBool("READ_ONLY_MODE", false)
+	c.Server.AllowURLs = func() []string {
+		urls := envutil.Getenv("ALLOWED_URLS", "")
+		if urls == "" {
+			return nil
+		}
+		return strings.Split(urls, ",")
+	}()
+	c.Client.FastProxyClient = createFasthttpClient()
 	cfg = &c
 	enableCache() // takes close to no resources, but can be used with dynamic query cache
 	loadRatelimitConfig()

proxy.go

@@ -2,26 +2,56 @@ package main
 
 import (
 	"crypto/tls"
+	"fmt"
+	"time"
 
 	fiber "github.com/gofiber/fiber/v2"
 	"github.com/gofiber/fiber/v2/middleware/proxy"
 	libpack_monitoring "github.com/lukaszraczylo/graphql-monitoring-proxy/monitoring"
+	"github.com/valyala/fasthttp"
 )
 
+func createFasthttpClient() *fasthttp.Client {
+	return &fasthttp.Client{
+		Name:                     "graphql_proxy",
+		NoDefaultUserAgentHeader: true,
+		TLSConfig: &tls.Config{
+			InsecureSkipVerify: true,
+		},
+		MaxConnsPerHost:               100,
+		MaxIdleConnDuration:           2 * time.Minute,
+		ReadTimeout:                   time.Second * 10,
+		WriteTimeout:                  time.Second * 10,
+		DisableHeaderNamesNormalizing: true,
+	}
+}
+
 func proxyTheRequest(c *fiber.Ctx) error {
+	if !checkAllowedURLs(c) {
+		cfg.Logger.Error("Request blocked", map[string]interface{}{"path": c.Path()})
+		cfg.Monitoring.Increment(libpack_monitoring.MetricsSkipped, nil)
+		c.Status(403).SendString("Request blocked - not allowed URL")
+		return nil
+	}
+
 	c.Request().Header.Add("X-Real-IP", c.IP())
-	c.Request().Header.Add("X-Forwarded-For", c.IP())
+	c.Request().Header.Add(fiber.HeaderXForwardedFor, string(c.Request().Header.Peek("X-Forwarded-For")))
 
-	proxy.WithTlsConfig(&tls.Config{
-		InsecureSkipVerify: true,
-	})
+	proxy.WithClient(cfg.Client.FastProxyClient)
 
+	cfg.Logger.Debug("Proxying the request", map[string]interface{}{"path": c.Path(), "body": string(c.Request().Body())})
 	err := proxy.DoRedirects(c, cfg.Server.HostGraphQL+c.Path(), 3)
 	if err != nil {
 		cfg.Logger.Error("Can't proxy the request", map[string]interface{}{"error": err.Error()})
 		cfg.Monitoring.Increment(libpack_monitoring.MetricsFailed, nil)
 		return err
 	}
+	cfg.Logger.Debug("Received proxied response", map[string]interface{}{"path": c.Path(), "response_body": string(c.Response().Body()), "response_code": c.Response().StatusCode()})
+
+	if c.Response().StatusCode() != 200 {
+		cfg.Monitoring.Increment(libpack_monitoring.MetricsFailed, nil)
+		return fmt.Errorf("Received non-200 response from the GraphQL server: %d", c.Response().StatusCode())
+	}
 
 	c.Response().Header.Del(fiber.HeaderServer)
 	return nil

server.go

@@ -31,6 +31,18 @@ func StartHTTPProxy() {
 	}
 }
 
+func checkAllowedURLs(c *fiber.Ctx) bool {
+	if len(cfg.Server.AllowURLs) == 0 {
+		return true
+	}
+	for _, allowedURL := range cfg.Server.AllowURLs {
+		if c.Path() == allowedURL {
+			return true
+		}
+	}
+	return false
+}
+
 func healthCheck(c *fiber.Ctx) error {
 	// query := `{ __typename }`
 	// _, err := cfg.Client.GQLClient.Query(query, nil, nil)
@@ -115,7 +127,13 @@ func processGraphQLRequest(c *fiber.Ctx) error {
 
 // Additional helper function to avoid code repetition
 func proxyAndCacheTheRequest(c *fiber.Ctx, queryCacheHash string, cache_time int) {
-	proxyTheRequest(c)
+	err := proxyTheRequest(c)
+	if err != nil {
+		cfg.Logger.Error("Can't proxy the request", map[string]interface{}{"error": err.Error()})
+		cfg.Monitoring.Increment(libpack_monitoring.MetricsFailed, nil)
+		c.Status(500).SendString("Can't proxy the request - try again later")
+		return
+	}
 	cfg.Cache.CacheClient.Set(queryCacheHash, c.Response().Body(), time.Duration(cache_time)*time.Second)
 	c.Send(c.Response().Body())
 }
@@ -131,6 +149,7 @@ func logAndMonitorRequest(c *fiber.Ctx, userID, opType, opName string, wasCached
 	if cfg.Server.AccessLog {
 		cfg.Logger.Info("Request processed", map[string]interface{}{
 			"ip":      c.IP(),
+			"fwd-ip":  string(c.Request().Header.Peek("X-Forwarded-For")),
 			"user_id": userID,
 			"op_type": opType,
 			"op_name": opName,

struct_config.go

@@ -1,10 +1,11 @@
 package main
 
 import (
-	"github.com/akyoto/cache"
 	graphql "github.com/lukaszraczylo/go-simple-graphql"
+	libpack_cache "github.com/lukaszraczylo/graphql-monitoring-proxy/cache"
 	libpack_logging "github.com/lukaszraczylo/graphql-monitoring-proxy/logging"
 	libpack_monitoring "github.com/lukaszraczylo/graphql-monitoring-proxy/monitoring"
+	"github.com/valyala/fasthttp"
 )
 
 // config is a struct that holds the configuration of the application.
@@ -19,6 +20,7 @@ type config struct {
 		HostGraphQL    string
 		AccessLog      bool
 		ReadOnlyMode   bool
+		AllowURLs      []string
 	}
 
 	Client struct {
@@ -27,12 +29,14 @@ type config struct {
 		RoleRateLimit    bool
 		RoleFromHeader   string
 		GQLClient        *graphql.BaseClient
+		FastProxyClient  *fasthttp.Client
+		proxy            string
 	}
 
 	Cache struct {
 		CacheEnable bool
 		CacheTTL    int
-		CacheClient *cache.Cache
+		CacheClient *libpack_cache.Cache
 	}
 
 	Security struct {