Create allow list for event when intospection is blocked but developers

really want to use certain subqueries.

README.md

@@ -48,6 +48,7 @@ I wanted to monitor the queries and responses of our graphql endpoint. Still, we
 | `CACHE_TTL`               | The cache TTL                           | `60`                       |
 | `LOG_LEVEL`               | The log level                           | `info`                     |
 | `BLOCK_SCHEMA_INTROSPECTION`| Blocks the schema introspection       | `false`                    |
+| `ALLOWED_INTROSPECTION`  | Allow only certain queries in introspection | ``                  |
 | `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`  |
@@ -107,6 +108,15 @@ You can enable the read-only mode by setting the `READ_ONLY_MODE` environment va
 
 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.
 
+### Blocking introspection
+
+You can block the schema introspection by setting the `BLOCK_SCHEMA_INTROSPECTION` environment variable to `true` - which will block all the queries with introspection parts, like:
+
+`__schema`, `__type`, `__typename`, `__directive`, `__directivelocation`, `__field`, `__inputvalue`, `__enumvalue`, `__typekind`, `__fieldtype`, `__inputobjecttype`, `__enumtype`, `__uniontype`, `__scalars`, `__objects`, `__interfaces`, `__unions`, `__enums`, `__inputobjects`, `__directives`
+
+If you'd like to keep blocking of the schema introspection on but allow one or more of from the list of above for any reason, you can use the `ALLOWED_INTROSPECTION` environment variable to specify the list of allowed queries.
+
+`ALLOWED_INTROSPECTION="__typename,__type"`
 
 ### Monitoring endpoint
 

graphql.go

@@ -96,7 +96,15 @@ func parseGraphQLQuery(c *fiber.Ctx) (operationType, operationName string, cache
 			if cfg.Security.BlockIntrospection {
 				for _, s := range oper.SelectionSet.Selections {
 					for _, s2 := range s.GetSelectionSet().Selections {
-						if _, exists := retrospectionQuerySet[s2.(*ast.Field).Name.Value]; exists {
+						if _, exists := retrospectionQuerySet[strings.ToLower(s2.(*ast.Field).Name.Value)]; exists {
+							if len(cfg.Security.IntrospectionAllowed) > 0 {
+								for _, introspectionQueryAllowed := range cfg.Security.IntrospectionAllowed {
+									if strings.EqualFold(strings.ToLower(introspectionQueryAllowed), strings.ToLower(s2.(*ast.Field).Name.Value)) {
+										cfg.Logger.Debug("Introspection query allowed, passing through", m)
+										return
+									}
+								}
+							}
 							cfg.Logger.Warning("Introspection query blocked", m)
 							cfg.Monitoring.Increment(libpack_monitoring.MetricsSkipped, nil)
 							c.Status(403).SendString("Introspection queries are not allowed")

main.go

@@ -30,6 +30,13 @@ func parseConfig() {
 	c.Cache.CacheEnable = envutil.GetBool("ENABLE_GLOBAL_CACHE", false)
 	c.Cache.CacheTTL = envutil.GetInt("CACHE_TTL", 60)
 	c.Security.BlockIntrospection = envutil.GetBool("BLOCK_SCHEMA_INTROSPECTION", false)
+	c.Security.IntrospectionAllowed = func() []string {
+		urls := envutil.Getenv("ALLOWED_INTROSPECTION", "")
+		if urls == "" {
+			return nil
+		}
+		return strings.Split(urls, ",")
+	}()
 	c.Logger = libpack_logging.NewLogger()
 	c.Client.GQLClient = graphql.NewConnection()
 	c.Client.GQLClient.SetEndpoint(c.Server.HostGraphQL)

struct_config.go

@@ -41,5 +41,6 @@ type config struct {
 
 	Security struct {
 		BlockIntrospection   bool
+		IntrospectionAllowed []string
 	}
 }