Merge pull request #60 from n9te9/feat/nested-key-directive

Feat/nested key directive

Author: n9te9

_example/Makefile

@@ -1,4 +1,4 @@
-.PHONY: test-ec test-fintech test-saas test-social test-travel test-all
+.PHONY: test-ec test-fintech test-saas test-social test-travel test-nestkey test-all
 .PHONY: partial-test-ec partial-test-fintech partial-test-saas partial-test-social partial-test-travel partial-test-all
 .PHONY: setup benchmark benchmark-ec benchmark-fintech benchmark-saas benchmark-social benchmark-travel compare-benchmark all-compare-benchmark
 
@@ -68,7 +68,10 @@ test-social:
 test-travel:
 	bash success_test_runner.sh travel
 
-test-all: test-ec test-fintech test-saas test-social test-travel
+test-nestkey:
+	bash success_test_runner.sh nestkey
+
+test-all: test-ec test-fintech test-saas test-social test-travel test-nestkey
 
 # Partial response test targets (service failure scenarios)
 partial-test-ec:

_example/nestkey/apollo/router.yaml

@@ -0,0 +1,19 @@
+supergraph:
+  path: /graphql
+
+cors:
+  allow_any_origin: true
+
+headers:
+  all:
+    request:
+      - propagate:
+          matching: .*
+
+include_subgraph_errors:
+  all: true
+
+telemetry:
+  instrumentation:
+    spans:
+      mode: spec_compliant

_example/nestkey/docker-compose.apollo.yaml

@@ -0,0 +1,16 @@
+services:
+  apollo-router:
+    image: ghcr.io/apollographql/router:v1.52.0
+    ports:
+      - "9701:4000"
+    volumes:
+      - ./apollo:/apollo
+    command: -s /apollo/supergraph.graphql -c /apollo/router.yaml --listen 0.0.0.0:4000
+    networks:
+      - default
+      - subgraph_net
+
+networks:
+  subgraph_net:
+    name: nestkey_default
+    external: true

_example/nestkey/docker-compose.gateway.yaml

@@ -0,0 +1,25 @@
+services:
+  go-gateway:
+    build:
+      context: ../..
+      dockerfile: _example/Dockerfile.gateway
+    ports:
+      - "9000:9000"
+    volumes:
+      - ./gateway.docker.yaml:/app/gateway.yaml
+    networks:
+      - default
+      - subgraph_net
+    deploy:
+      resources:
+        limits:
+          cpus: '2.0'
+          memory: 512M
+        reservations:
+          cpus: '0.5'
+          memory: 128M
+
+networks:
+  subgraph_net:
+    name: nestkey_default
+    external: true

_example/nestkey/docker-compose.yaml

@@ -0,0 +1,18 @@
+services:
+  locations:
+    build:
+      context: ./locations
+      dockerfile: Dockerfile
+    ports:
+      - "8601:8080"
+    environment:
+      - PORT=8080
+
+  weather:
+    build:
+      context: ./weather
+      dockerfile: Dockerfile
+    ports:
+      - "8602:8080"
+    environment:
+      - PORT=8080

_example/nestkey/gateway.docker.yaml

@@ -0,0 +1,16 @@
+endpoint: /graphql
+port: 9000
+service_name: nestkey-gateway
+timeout_duration: "5s"
+request_timeout: "30s"
+services:
+- name: locations
+  host: http://locations:8080/query
+  retry:
+    attempts: 3
+    timeout: "5s"
+- name: weather
+  host: http://weather:8080/query
+  retry:
+    attempts: 3
+    timeout: "5s"

_example/nestkey/gateway.yaml

@@ -0,0 +1,16 @@
+endpoint: /graphql
+port: 9000
+service_name: nestkey-gateway
+timeout_duration: "5s"
+request_timeout: "30s"
+services:
+- name: locations
+  host: http://localhost:8601/query
+  retry:
+    attempts: 3
+    timeout: "5s"
+- name: weather
+  host: http://localhost:8602/query
+  retry:
+    attempts: 3
+    timeout: "5s"

_example/nestkey/locations/Dockerfile

@@ -0,0 +1,11 @@
+FROM golang:1.25-alpine
+
+WORKDIR /app
+
+COPY go.mod ./
+RUN go mod download
+
+COPY . .
+RUN go build -o server .
+
+CMD ["./server"]

_example/nestkey/locations/go.mod

@@ -0,0 +1,3 @@
+module github.com/n9te9/go-graphql-federation-gateway/_example/nestkey/locations
+
+go 1.25.4

_example/nestkey/locations/main.go

@@ -0,0 +1,149 @@
+// locations service: owns Location @key(fields: "coordinate { lat lng }")
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"os"
+	"strings"
+)
+
+const sdl = `extend schema
+  @link(url: "https://specs.apollo.dev/federation/v2.0", import: ["@key", "@shareable"])
+
+type Location @key(fields: "coordinate { lat lng }") {
+  coordinate: Coordinate!
+  name: String!
+}
+
+type Coordinate @shareable {
+  lat: Float!
+  lng: Float!
+}
+
+type Query {
+  location(id: ID!): Location
+}`
+
+type coordinate struct {
+	Lat float64 `json:"lat"`
+	Lng float64 `json:"lng"`
+}
+
+type location struct {
+	Name       string     `json:"name"`
+	Coordinate coordinate `json:"coordinate"`
+}
+
+// locationDB stores all known locations indexed by id.
+var locationDB = map[string]location{
+	"loc1": {Name: "Tokyo Station", Coordinate: coordinate{Lat: 35.6762, Lng: 139.6503}},
+	"loc2": {Name: "Shibuya", Coordinate: coordinate{Lat: 35.6580, Lng: 139.7016}},
+	"loc3": {Name: "Shinjuku", Coordinate: coordinate{Lat: 35.6896, Lng: 139.6917}},
+}
+
+// findByCoordinate returns the location that has the given (lat, lng) coordinate.
+func findByCoordinate(lat, lng float64) *location {
+	for _, loc := range locationDB {
+		if loc.Coordinate.Lat == lat && loc.Coordinate.Lng == lng {
+			l := loc
+			return &l
+		}
+	}
+	return nil
+}
+
+type gqlRequest struct {
+	Query     string                 `json:"query"`
+	Variables map[string]interface{} `json:"variables"`
+}
+
+func writeJSON(w http.ResponseWriter, v interface{}) {
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(v) //nolint:errcheck
+}
+
+func handleQuery(w http.ResponseWriter, r *http.Request) {
+	var req gqlRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, map[string]interface{}{"errors": []map[string]interface{}{{"message": err.Error()}}})
+		return
+	}
+
+	switch {
+	case strings.Contains(req.Query, "_service"):
+		writeJSON(w, map[string]interface{}{
+			"data": map[string]interface{}{"_service": map[string]interface{}{"sdl": sdl}},
+		})
+	case strings.Contains(req.Query, "_entities"):
+		handleEntities(w, req)
+	case strings.Contains(req.Query, "location"):
+		handleLocationQuery(w, req)
+	default:
+		writeJSON(w, map[string]interface{}{"data": map[string]interface{}{"__typename": "Query"}})
+	}
+}
+
+func handleLocationQuery(w http.ResponseWriter, req gqlRequest) {
+	id, _ := req.Variables["id"].(string)
+	loc, ok := locationDB[id]
+	if !ok {
+		writeJSON(w, map[string]interface{}{"data": map[string]interface{}{"location": nil}})
+		return
+	}
+	writeJSON(w, map[string]interface{}{
+		"data": map[string]interface{}{
+			"location": map[string]interface{}{
+				"__typename": "Location",
+				"name":       loc.Name,
+				"coordinate": map[string]interface{}{
+					"lat": loc.Coordinate.Lat,
+					"lng": loc.Coordinate.Lng,
+				},
+			},
+		},
+	})
+}
+
+func handleEntities(w http.ResponseWriter, req gqlRequest) {
+	repsRaw, _ := req.Variables["representations"].([]interface{})
+	entities := make([]interface{}, 0, len(repsRaw))
+	for _, repRaw := range repsRaw {
+		repMap, ok := repRaw.(map[string]interface{})
+		if !ok {
+			entities = append(entities, nil)
+			continue
+		}
+		coordRaw, ok := repMap["coordinate"].(map[string]interface{})
+		if !ok {
+			entities = append(entities, nil)
+			continue
+		}
+		lat, _ := coordRaw["lat"].(float64)
+		lng, _ := coordRaw["lng"].(float64)
+		loc := findByCoordinate(lat, lng)
+		if loc == nil {
+			entities = append(entities, nil)
+			continue
+		}
+		entities = append(entities, map[string]interface{}{
+			"__typename": "Location",
+			"name":       loc.Name,
+			"coordinate": map[string]interface{}{"lat": loc.Coordinate.Lat, "lng": loc.Coordinate.Lng},
+		})
+	}
+	writeJSON(w, map[string]interface{}{
+		"data": map[string]interface{}{"_entities": entities},
+	})
+}
+
+func main() {
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+	}
+	http.HandleFunc("/query", handleQuery)
+	log.Printf("locations service listening on :%s", port)
+	log.Fatal(http.ListenAndServe(":"+port, nil))
+}