#20 headers support

Author: Adven27

README.md

@@ -24,6 +24,7 @@ curl -X POST http://localhost:8888/__admin/mappings \
     "request": {
         "method": "POST",
         "url": "/BalanceService/getUserBalance",
+        "headers": {"withAmount": {"matches": "\\d+\\.*\\d*"} },
         "bodyPatterns" : [ {
             "equalToJson" : { "id": "1", "currency": "EUR" }
         } ]
@@ -32,7 +33,7 @@ curl -X POST http://localhost:8888/__admin/mappings \
         "status": 200,
         "jsonBody": { 
             "balance": { 
-                "amount": { "value": { "decimal" : "100.0" }, "value_present": true },
+                "amount": { "value": { "decimal" : "{{request.headers.withAmount}}" }, "value_present": true },
                 "currency": { "value": "EUR", "value_present": true }
             } 
         }
@@ -42,7 +43,7 @@ curl -X POST http://localhost:8888/__admin/mappings \
 
 3) Check 
 ```json
-grpcurl -plaintext -d '{"id": 1, "currency": "EUR"}' localhost:50000 api.wallet.BalanceService/getUserBalance
+grpcurl -H 'withAmount: 100.0' -plaintext -d '{"id": 1, "currency": "EUR"}' localhost:50000 api.wallet.BalanceService/getUserBalance
 ```
 
 Should get response:

build.gradle

@@ -1,5 +1,5 @@
 plugins {
-    id 'org.springframework.boot' version '2.5.4'
+    id 'org.springframework.boot' version '2.5.5'
     id 'io.spring.dependency-management' version '1.0.11.RELEASE'
     id 'java'
     id 'com.google.protobuf' version '0.8.16'
@@ -13,16 +13,17 @@ repositories {
     mavenCentral()
 }
 
-def grpcVersion = '1.40.1'
+def grpcVersion = '1.41.0'
+def wiremockVersion = '2.31.0'
 def protobufVersion = '3.16.0'
 def protocVersion = protobufVersion
 
 dependencies {
     implementation 'org.springframework.boot:spring-boot-starter'
     implementation 'org.springframework.boot:spring-boot-starter-aop'
-    implementation "io.grpc:grpc-all:${grpcVersion}"
+    implementation "io.grpc:grpc-all:$grpcVersion"
+    implementation "com.github.tomakehurst:wiremock-jre8-standalone:$wiremockVersion"
     implementation 'org.xerial.snappy:snappy-java:1.1.8.4'
-    implementation 'com.github.tomakehurst:wiremock-jre8-standalone:2.31.0'
 }
 
 protobuf {

src/main/java/io/adven/grpc/wiremock/BadHttpResponseException.java

@@ -1,7 +1,7 @@
 package io.adven.grpc.wiremock;
 
 public class BadHttpResponseException extends RuntimeException {
-    private int statusCode;
+    private final int statusCode;
 
     public BadHttpResponseException(int statusCode, String errorMessage) {
         super(errorMessage);

src/main/java/io/adven/grpc/wiremock/GrpcWiremock.java

@@ -19,6 +19,7 @@
 import java.util.Optional;
 import java.util.concurrent.CountDownLatch;
 
+import static io.grpc.ServerInterceptors.intercept;
 import static java.util.stream.Collectors.joining;
 
 @SpringBootApplication
@@ -62,7 +63,7 @@ public void start() throws IOException {
                 .addService(ProtoReflectionService.newInstance());
 
             setProperties(builder);
-            services.forEach(builder::addService);
+            services.forEach(s -> builder.addService(intercept(s, new HeaderPropagationInterceptor())));
             server = builder.build().start();
             LOG.info(summary(server));
             startDaemonAwaitThread();

src/main/java/io/adven/grpc/wiremock/HeaderPropagationInterceptor.java

@@ -0,0 +1,33 @@
+package io.adven.grpc.wiremock;
+
+import io.grpc.Context;
+import io.grpc.Contexts;
+import io.grpc.Metadata;
+import io.grpc.ServerCall;
+import io.grpc.ServerCallHandler;
+import io.grpc.ServerInterceptor;
+
+import java.util.Map;
+
+import static io.grpc.Metadata.ASCII_STRING_MARSHALLER;
+import static io.grpc.Metadata.Key.of;
+import static java.util.function.Function.identity;
+import static java.util.stream.Collectors.toMap;
+
+public class HeaderPropagationInterceptor implements ServerInterceptor {
+    public static final Context.Key<Map<String, String>> HEADERS = Context.key("GRPC_WIREMOCK_HEADERS");
+
+    @Override
+    public <Req, Resp> ServerCall.Listener<Req> interceptCall(ServerCall<Req, Resp> call, final Metadata headers, ServerCallHandler<Req, Resp> next) {
+        return Contexts.interceptCall(
+            Context.current().withValue(HEADERS, asMap(headers)),
+            call,
+            headers,
+            next
+        );
+    }
+
+    private Map<String, String> asMap(Metadata headers) {
+        return headers.keys().stream().collect(toMap(identity(), k -> headers.get(of(k, ASCII_STRING_MARSHALLER))));
+    }
+}

src/main/java/io/adven/grpc/wiremock/HttpMock.java

@@ -20,6 +20,9 @@
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
 import java.util.Map;
+import java.util.stream.Stream;
+
+import static io.adven.grpc.wiremock.HeaderPropagationInterceptor.HEADERS;
 
 @Component
 public class HttpMock {
@@ -73,13 +76,17 @@ public void destroy() {
     }
 
     public Message send(Object message, String path, Class<?> aClass) throws IOException, InterruptedException {
-        return ProtoJsonUtil.fromJson(request(path, message).body(), aClass);
+        return ProtoJsonUtil.fromJson(request(path, message, HEADERS.get()).body(), aClass);
     }
 
-    private HttpResponse<String> request(String path, Object message) throws IOException, InterruptedException {
-        LOG.info("Grpc request {}:\n{}", path, message);
+    private HttpResponse<String> request(String path, Object message, Map<String, String> headers) throws IOException, InterruptedException {
+        LOG.info("Grpc request {}:\nHeaders: {}\nMessage:\n{}", path, headers, message);
         final HttpResponse<String> response = httpClient.send(
-            HttpRequest.newBuilder().uri(URI.create(server.baseUrl() + "/" + path)).POST(asJson(message)).build(),
+            HttpRequest.newBuilder()
+                .uri(URI.create(server.baseUrl() + "/" + path))
+                .POST(asJson(message))
+                .headers(headers.entrySet().stream().flatMap(e -> Stream.of(e.getKey(), e.getValue())).toArray(String[]::new))
+                .build(),
             HttpResponse.BodyHandlers.ofString()
         );
         if (response.statusCode() != 200) {