If proxying of the query fails - return 500.

Makefile

@@ -11,7 +11,7 @@ help:  ## display this help
 
 .PHONY: run
 run: build ## run application
-	@LOG_LEVEL=debug BLOCK_SCHEMA_INTROSPECTION=false JWT_ROLE_RATE_LIMIT=false JWT_ROLE_CLAIM_PATH="Hasura.x-hasura-default-role" JWT_USER_CLAIM_PATH="Hasura.x-hasura-user-id" HOST_GRAPHQL=https://hasura8.lan/v1/graphql ./graphql-proxy
+	@LOG_LEVEL=debug BLOCK_SCHEMA_INTROSPECTION=false JWT_ROLE_RATE_LIMIT=false JWT_ROLE_CLAIM_PATH="Hasura.x-hasura-default-role" JWT_USER_CLAIM_PATH="Hasura.x-hasura-user-id" HOST_GRAPHQL=https://hasura8.lan/ ./graphql-proxy
 
 .PHONY: build
 build: ## build the binary

README.md

@@ -14,7 +14,7 @@ I wanted to monitor the queries and responses of our graphql endpoint. Still, we
 
 ### Endpoints
 
-* `:8080/v1/graphql` - the graphql endpoint
+* `:8080/*` - the graphql passthrough endpoint
 * `:9393/metrics` - the prometheus metrics endpoint
 * `:8080/healthz` - the healthcheck endpoint
 
@@ -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
@@ -38,7 +39,7 @@ I wanted to monitor the queries and responses of our graphql endpoint. Still, we
 |---------------------------|------------------------------------------|----------------------------|
 | `MONITORING_PORT`         | The port to expose the metrics endpoint  | `9393`                     |
 | `PORT_GRAPHQL`            | The port to expose the graphql endpoint  | `8080`                     |
-| `HOST_GRAPHQL`            | The host to proxy the graphql endpoint   | `http://localhost/v1/graphql` |
+| `HOST_GRAPHQL`            | The host to proxy the graphql endpoint   | `http://localhost/` |
 | `JWT_USER_CLAIM_PATH`     | Path to the user claim in the JWT token  | ``                         |
 | `JWT_ROLE_CLAIM_PATH`     | Path to the role claim in the JWT token  | ``                         |
 | `JWT_ROLE_FROM_HEADER`    | Header name to extract the role from     | ``                         |
@@ -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:

go.mod

@@ -12,9 +12,10 @@ require (
 	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 (
@@ -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

@@ -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=

graphql.go

@@ -36,12 +36,13 @@ var retrospection_queries = []string{
 // Saving the introspection queries as a map O(1) operation instead of O(n) for a slice.
 var retrospectionQuerySet = make(map[string]struct{}, len(retrospection_queries))
 
-func parseGraphQLQuery(c *fiber.Ctx) (operationType, operationName string, cacheRequest bool, cache_time int, should_block bool) {
+func parseGraphQLQuery(c *fiber.Ctx) (operationType, operationName string, cacheRequest bool, cache_time int, should_block bool, should_ignore bool) {
+	should_ignore = true
 	m := make(map[string]interface{})
 	err := json.Unmarshal(c.Body(), &m)
 	if err != nil {
-		cfg.Logger.Error("Can't unmarshal the request", map[string]interface{}{"error": err.Error(), "body": string(c.Body())})
-		cfg.Monitoring.Increment(libpack_monitoring.MetricsFailed, nil)
+		cfg.Logger.Debug("Can't unmarshal the request", map[string]interface{}{"error": err.Error(), "body": string(c.Body())})
+		cfg.Monitoring.Increment(libpack_monitoring.MetricsSkipped, nil)
 		return
 	}
 	// get the query
@@ -59,6 +60,7 @@ func parseGraphQLQuery(c *fiber.Ctx) (operationType, operationName string, cache
 		return
 	}
 
+	should_ignore = false
 	operationName = "undefined"
 	for _, d := range p.Definitions {
 		if oper, ok := d.(*ast.OperationDefinition); ok {

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"
@@ -20,7 +22,7 @@ func parseConfig() {
 	var c config
 	c.Server.PortGraphQL = envutil.GetInt("PORT_GRAPHQL", 8080)
 	c.Server.PortMonitoring = envutil.GetInt("MONITORING_PORT", 9393)
-	c.Server.HostGraphQL = envutil.Getenv("HOST_GRAPHQL", "http://localhost/v1/graphql")
+	c.Server.HostGraphQL = envutil.Getenv("HOST_GRAPHQL", "http://localhost/")
 	c.Client.JWTUserClaimPath = envutil.Getenv("JWT_USER_CLAIM_PATH", "")
 	c.Client.JWTRoleClaimPath = envutil.Getenv("JWT_ROLE_CLAIM_PATH", "")
 	c.Client.RoleFromHeader = envutil.Getenv("ROLE_FROM_HEADER", "")
@@ -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)
 
-	err := proxy.DoRedirects(c, cfg.Server.HostGraphQL, 3)
+	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

@@ -21,7 +21,8 @@ func StartHTTPProxy() {
 		AllowOrigins: "*",
 	}))
 
-	server.Post("/v1/graphql", processGraphQLRequest)
+	server.Post("/*", processGraphQLRequest)
+	server.Get("/*", proxyTheRequest)
 
 	server.Get("/healthz", healthCheck)
 	err := server.Listen(fmt.Sprintf(":%d", cfg.Server.PortGraphQL))
@@ -30,6 +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)
@@ -70,11 +83,16 @@ func processGraphQLRequest(c *fiber.Ctx) error {
 		}
 	}
 
-	opType, opName, cacheFromQuery, cache_time, shouldBlock := parseGraphQLQuery(c)
+	opType, opName, cacheFromQuery, cache_time, shouldBlock, should_ignore := parseGraphQLQuery(c)
 	if shouldBlock {
 		return nil
 	}
 
+	if should_ignore {
+		cfg.Logger.Debug("Request passed as-is - not a GraphQL")
+		return proxyTheRequest(c)
+	}
+
 	if cache_time > 0 {
 		cfg.Logger.Debug("Cache time set via query", map[string]interface{}{"cache_time": cache_time})
 		cache_time = cfg.Cache.CacheTTL
@@ -109,7 +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())
 }
@@ -125,6 +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

@@ -5,6 +5,7 @@ import (
 	graphql "github.com/lukaszraczylo/go-simple-graphql"
 	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 {
@@ -27,6 +29,8 @@ type config struct {
 		RoleRateLimit    bool
 		RoleFromHeader   string
 		GQLClient        *graphql.BaseClient
+		FastProxyClient  *fasthttp.Client
+		proxy            string
 	}
 
 	Cache struct {