com.google.appengine.tools.development.ApiServlet Maven / Gradle / Ivy
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SDK for dev_appserver (local development) with some of the dependencies shaded (repackaged)
/*
* Copyright 2021 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.appengine.tools.development;
import com.google.apphosting.api.ApiProxy.ApiProxyException;
import com.google.apphosting.api.ApiProxy.CallNotFoundException;
import com.google.apphosting.base.protos.api.RemoteApiPb;
import com.google.apphosting.base.protos.api.RemoteApiPb.RpcError;
import com.google.appengine.repackaged.com.google.common.annotations.VisibleForTesting;
import com.google.appengine.repackaged.com.google.common.base.Ascii;
import com.google.appengine.repackaged.com.google.common.primitives.Doubles;
import com.google.appengine.repackaged.com.google.protobuf.ByteString;
import com.google.appengine.repackaged.com.google.protobuf.ExtensionRegistry;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.InetSocketAddress;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet handling POST requests to serve App Engine Standard API calls implemented by the API stub
* implementations used by the dev app server. This can be used in a local dev environment to
* emulate App Engine APIs, or in a test environment. The protocol buffer used is the same as the
* App Engine remote APIs documented at
* https://cloud.google.com/appengine/docs/standard/java/tools/remoteapi and the one used from the
* Java clones in production to make API calls.
*/
public class ApiServlet extends HttpServlet {
private static final Logger logger = Logger.getLogger(ApiServlet.class.getName());
private static final String RPC_ENDPOINT_HEADER = "X-Google-RPC-Service-Endpoint";
private static final String RPC_ENDPOINT_VALUE = "app-engine-apis";
private static final String RPC_METHOD_HEADER = "X-Google-RPC-Service-Method";
private static final String RPC_METHOD_VALUE = "/VMRemoteAPI.CallRemoteAPI";
private static final String CONTENT_TYPE_HEADER = "Content-Type";
private static final String CONTENT_TYPE_VALUE = "application/octet-stream";
private static final String DEADLINE_HEADER = "X-Google-RPC-Service-Deadline";
private static final String RUNTIME_PORT_CONFIG = "java_runtime_port";
private static final String RUNTIME_HOST_CONFIG = "java_runtime_host";
private static final String EXECUTOR_POOL_SIZE = "executor_pool_size";
private final Map methodCache = new ConcurrentHashMap<>();
private ApiProxyLocal apiProxyLocal;
private int serverPort;
private String serverHost;
private ExecutorService executor;
private static final int EXECUTOR_THREAD_POOL_DEFAULT_SIZE = 10;
/**
* Configure the APIServlet with 2 servlet init paramerters:
*
*
* java_runtime_port: the local port of the java clone. This is needed for the taskqueue APIs to
* be able to post callback to the clone.
* java_runtime_host: the hostname of the java clone. (default to localhost).
* * executor_pool_size: size of the threadpool handling API calls. Default is 10.
*
*/
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
if (config.getInitParameter(RUNTIME_PORT_CONFIG) == null) {
throw new NumberFormatException("Missing " + RUNTIME_PORT_CONFIG + " init parameter.");
}
serverPort = Integer.parseInt(config.getInitParameter(RUNTIME_PORT_CONFIG));
if (config.getInitParameter(RUNTIME_HOST_CONFIG) == null) {
serverHost = "localhost";
} else {
serverHost = config.getInitParameter(RUNTIME_HOST_CONFIG);
}
apiProxyLocal = new ApiProxyLocalFactory().create(new LocalEnv(serverHost, serverPort));
// True to put the datastore into "memory-only" mode.
apiProxyLocal.setProperty("datastore.no_storage", "true");
String executorSize = config.getInitParameter(EXECUTOR_POOL_SIZE);
int poolSize =
(executorSize == null) ? EXECUTOR_THREAD_POOL_DEFAULT_SIZE : Integer.parseInt(executorSize);
executor = Executors.newFixedThreadPool(poolSize);
}
@Override
public void destroy() {
executor.shutdown();
}
@Override
public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
Double deadline = validateHeaders(request);
try (InputStream in = request.getInputStream()) {
RemoteApiPb.Request requestPb =
RemoteApiPb.Request.parseFrom(in, ExtensionRegistry.getEmptyRegistry());
if (in.read() >= 0) {
throw new IllegalArgumentException("Extra data after request");
}
response.addHeader(CONTENT_TYPE_HEADER, CONTENT_TYPE_VALUE);
RemoteApiPb.Response responsePb = handleRequestInThread(apiProxyLocal, requestPb, deadline);
try (OutputStream out = response.getOutputStream()) {
out.write(responsePb.toByteArray());
}
} catch (RuntimeException e) {
logger.log(Level.WARNING, "bad request:", e);
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
}
}
// Checks mandatory headers, and return the expected deadline (in seconds) for the request.
@VisibleForTesting
Double validateHeaders(HttpServletRequest request) {
String endpoint = request.getHeader(RPC_ENDPOINT_HEADER);
if (!RPC_ENDPOINT_VALUE.equals(endpoint)) {
throw new IllegalArgumentException(
RPC_ENDPOINT_HEADER + " should be " + RPC_ENDPOINT_VALUE + ", not " + endpoint + ".");
}
String method = request.getHeader(RPC_METHOD_HEADER);
if (!RPC_METHOD_VALUE.equals(method)) {
throw new IllegalArgumentException(
RPC_METHOD_HEADER + " should be " + RPC_METHOD_VALUE + ", not " + method + ".");
}
String contentType = request.getHeader(CONTENT_TYPE_HEADER);
if (!CONTENT_TYPE_VALUE.equals(contentType)) {
throw new IllegalArgumentException(
CONTENT_TYPE_HEADER + " should be " + CONTENT_TYPE_VALUE + ", not " + contentType + ".");
}
String deadlineString = request.getHeader(DEADLINE_HEADER);
Double deadline = (deadlineString == null) ? null : Doubles.tryParse(deadlineString);
if (deadline == null) {
throw new IllegalArgumentException(
"Missing or incorrect deadline header in request: " + deadlineString + ".");
}
return deadline;
}
// Simulates deadline handling by running the request in a separate thread and waiting for
// the result with a deadline.
private RemoteApiPb.Response handleRequestInThread(
final ApiProxyLocal apiProxy, final RemoteApiPb.Request requestPb, double deadline) {
Callable task =
new Callable() {
@Override
public RemoteApiPb.Response call() {
return handle(apiProxy, requestPb);
}
};
Future future = executor.submit(task);
try {
return future.get((long) (deadline * 1000), TimeUnit.MILLISECONDS);
} catch (ExecutionException e) {
return exceptionResponse(e);
} catch (InterruptedException | TimeoutException e) {
future.cancel(/* mayInterruptIfRunning= */ true);
return timeoutResponse(deadline);
}
}
/**
* Invokes an API call using the Java implementations.
*
* @param apiProxy the local ApiProxy environment
* @param packageName the name of the API service, eg datastore_v3
* @param methodName the name of the API method, eg Query
* @param requestBytes the serialized proto, eg DatastoreV3Pb.Query
* @return the serialized API response
*/
@VisibleForTesting
byte[] invokeApiMethodJava(
ApiProxyLocal apiProxy, String packageName, String methodName, byte[] requestBytes)
throws IllegalAccessException, InstantiationException, InvocationTargetException,
NoSuchMethodException {
LocalRpcService service = apiProxy.getService(packageName);
if (service == null) {
throw new CallNotFoundException(packageName, methodName);
}
Method method = getDispatchMethod(service, packageName, methodName);
LocalRpcService.Status status = new LocalRpcService.Status();
// For a method like public QueryResult runQuery(Status status, Query query) {...}
// return the Query class.
Class requestClass = method.getParameterTypes()[1];
Object request = ApiUtils.convertBytesToPb(requestBytes, requestClass);
return ApiUtils.convertPbToBytes(method.invoke(service, status, request));
}
@VisibleForTesting
Method getDispatchMethod(LocalRpcService service, String packageName, String methodName) {
// e.g. RunQuery --> runQuery
String dispatchName = Ascii.toLowerCase(methodName.charAt(0)) + methodName.substring(1);
// e.g. datastore_v3.runQuery
String methodId = packageName + "." + dispatchName;
Method method = methodCache.get(methodId);
if (method != null) {
return method;
}
for (Method candidate : service.getClass().getMethods()) {
if (dispatchName.equals(candidate.getName())) {
methodCache.put(methodId, candidate);
return candidate;
}
}
throw new CallNotFoundException(packageName, methodName);
}
@VisibleForTesting
RemoteApiPb.Response handle(ApiProxyLocal apiProxy, RemoteApiPb.Request request) {
byte[] resp;
try {
resp =
invokeApiMethodJava(
apiProxy,
request.getServiceName(),
request.getMethod(),
request.getRequest().toByteArray());
} catch (InvocationTargetException ex) {
logger.log(
Level.INFO,
"Exception calling service"
+ request.getServiceName()
+ " and method: "
+ request.getMethod(), ex);
throw new ApiProxyException(
"API invocation error for service: "
+ request.getServiceName()
+ " and method: "
+ request.getMethod(),
ex.getCause());
} catch (ReflectiveOperationException | RuntimeException | Error ex) {
logger.log(
Level.INFO,
"Exception calling service"
+ request.getServiceName()
+ " and method: "
+ request.getMethod(), ex);
throw new CallNotFoundException(request.getServiceName(), request.getMethod());
}
return RemoteApiPb.Response.newBuilder().setResponse(ByteString.copyFrom(resp)).build();
}
private RemoteApiPb.Response timeoutResponse(double deadline) {
return RemoteApiPb.Response.newBuilder()
.setRpcError(
RemoteApiPb.RpcError.newBuilder()
.setCode(RemoteApiPb.RpcError.ErrorCode.DEADLINE_EXCEEDED.getNumber())
.setDetail("Deadline of " + deadline + "s was exceeded"))
.build();
}
private RemoteApiPb.Response exceptionResponse(ExecutionException exception) {
RpcError rpcError =
RemoteApiPb.RpcError.newBuilder()
.setCode(RemoteApiPb.RpcError.ErrorCode.BAD_REQUEST.getNumber())
.setDetail("Execution exception " + exception.getMessage())
.build();
RemoteApiPb.Response.Builder response = RemoteApiPb.Response.newBuilder();
ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
try (ObjectOutput out = new ObjectOutputStream(byteStream)) {
out.writeObject(exception);
} catch (IOException e) {
logger.log(Level.SEVERE, "Cannot serialize the exception: ", e);
}
byte[] serializedException = byteStream.toByteArray();
response.setJavaException(ByteString.copyFrom(serializedException));
response.setRpcError(rpcError);
return response.build();
}
private static class LocalEnv implements LocalServerEnvironment {
private final String javaRuntimeHost;
private final int javaRuntimePort;
LocalEnv(String javaRuntimeHost, int javaRuntimePort) {
this.javaRuntimeHost = javaRuntimeHost;
this.javaRuntimePort = javaRuntimePort;
}
@Override
public File getAppDir() {
return new File(".");
}
@Override
public String getAddress() {
return new InetSocketAddress(javaRuntimePort).getHostString();
}
@Override
public String getHostName() {
return javaRuntimeHost;
}
@Override
public int getPort() {
return javaRuntimePort;
}
@Override
public void waitForServerToStart() throws InterruptedException {}
@Override
public boolean simulateProductionLatencies() {
return false;
}
@Override
public boolean enforceApiDeadlines() {
// Not used by this servlet. Instead, the value of DEADLINE_HEADER is used for deadlines.
return false;
}
}
}