Java tutorial
/* * Copyright 2018 The gRPC Authors * * 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 * * http://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 io.grpc.alts; import static java.nio.charset.StandardCharsets.UTF_8; import com.google.common.annotations.VisibleForTesting; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.nio.file.Files; import java.nio.file.Paths; import java.util.logging.Level; import java.util.logging.Logger; import org.apache.commons.lang3.SystemUtils; /** Class for checking if the system is running on Google Cloud Platform (GCP). */ final class CheckGcpEnvironment { private static final Logger logger = Logger.getLogger(CheckGcpEnvironment.class.getName()); private static final String DMI_PRODUCT_NAME = "/sys/class/dmi/id/product_name"; private static final String WINDOWS_COMMAND = "powershell.exe"; private static Boolean cachedResult = null; // Construct me not! private CheckGcpEnvironment() { } static synchronized boolean isOnGcp() { if (cachedResult == null) { cachedResult = isRunningOnGcp(); } return cachedResult; } @VisibleForTesting static boolean checkProductNameOnLinux(BufferedReader reader) throws IOException { String name = reader.readLine().trim(); return name.equals("Google") || name.equals("Google Compute Engine"); } @VisibleForTesting static boolean checkBiosDataOnWindows(BufferedReader reader) throws IOException { String line; while ((line = reader.readLine()) != null) { if (line.startsWith("Manufacturer")) { String name = line.substring(line.indexOf(':') + 1).trim(); return name.equals("Google"); } } return false; } private static boolean isRunningOnGcp() { try { if (SystemUtils.IS_OS_LINUX) { // Checks GCE residency on Linux platform. return checkProductNameOnLinux(Files.newBufferedReader(Paths.get(DMI_PRODUCT_NAME), UTF_8)); } else if (SystemUtils.IS_OS_WINDOWS) { // Checks GCE residency on Windows platform. Process p = new ProcessBuilder().command(WINDOWS_COMMAND, "Get-WmiObject", "-Class", "Win32_BIOS") .start(); return checkBiosDataOnWindows(new BufferedReader(new InputStreamReader(p.getInputStream(), UTF_8))); } } catch (IOException e) { logger.log(Level.WARNING, "Fail to read platform information: ", e); return false; } // Platforms other than Linux and Windows are not supported. return false; } }