feat : GraphQL Context 추가

놀이터(예제 코드 작성)/graphql-kotlin/README.md

@@ -9,3 +9,6 @@
 - [Configuration Properties](https://opensource.expediagroup.com/graphql-kotlin/docs/server/spring-server/spring-properties)
 - [Subscriptions](https://opensource.expediagroup.com/graphql-kotlin/docs/server/spring-server/spring-subscriptions)
 - [MVN Repository - GraphQL Kotlin Spring Server](https://mvnrepository.com/artifact/com.expediagroup/graphql-kotlin-spring-server)
+- [Contextual Data](https://opensource.expediagroup.com/graphql-kotlin/docs/schema-generator/execution/contextual-data/)
+- [Federation Tracing](https://opensource.expediagroup.com/graphql-kotlin/docs/schema-generator/federation/federation-tracing/)
+- [Configuration Properties](https://opensource.expediagroup.com/graphql-kotlin/docs/server/spring-server/spring-properties/)

놀이터(예제 코드 작성)/graphql-kotlin/src/main/kotlin/com/banjjoknim/graphqlkotlin/GraphQLContextFactory.kt

@@ -0,0 +1,29 @@
+package com.banjjoknim.graphqlkotlin
+
+import com.expediagroup.graphql.server.spring.execution.DefaultSpringGraphQLContextFactory
+import org.springframework.stereotype.Component
+import org.springframework.web.reactive.function.server.ServerRequest
+
+/**
+ * # [Generating GraphQL Context](https://opensource.expediagroup.com/graphql-kotlin/docs/server/spring-server/spring-graphql-context)
+ *
+ * graphql-kotlin-spring-server provides a Spring specific implementation of GraphQLContextFactory and the context.
+ *
+ * SpringGraphQLContext (deprecated) - Implements the Spring ServerRequest and federation tracing HTTPRequestHeaders
+ *
+ * SpringGraphQLContextFactory - Generates GraphQL context map with federated tracing information per request
+ *
+ * If you are using graphql-kotlin-spring-server, you should extend DefaultSpringGraphQLContextFactory to automatically support federated tracing.
+ *
+ * Once your application is configured to build your custom GraphQL context map, you can then access it through a data fetching environment argument.
+ *
+ * While executing the query, data fetching environment will be automatically injected to the function input arguments.
+ *
+ * This argument will not appear in the GraphQL schema.
+ */
+@Component
+class GraphQLContextFactory : DefaultSpringGraphQLContextFactory() {
+    override suspend fun generateContextMap(request: ServerRequest): Map<*, Any> = super.generateContextMap(request) + mapOf(
+        "myCustomValue" to (request.headers().firstHeader("MyHeader") ?: "defaultContext")
+    )
+}