| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // 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 com.google.devtools.build.lib.sandbox; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.common.collect.Maps; |
| import com.google.common.io.ByteStreams; |
| import com.google.devtools.build.lib.actions.ExecException; |
| import com.google.devtools.build.lib.actions.ExecutionRequirements; |
| import com.google.devtools.build.lib.actions.Spawn; |
| import com.google.devtools.build.lib.actions.Spawns; |
| import com.google.devtools.build.lib.actions.UserExecException; |
| import com.google.devtools.build.lib.analysis.BlazeDirectories; |
| import com.google.devtools.build.lib.exec.TreeDeleter; |
| import com.google.devtools.build.lib.exec.local.LocalEnvProvider; |
| import com.google.devtools.build.lib.exec.local.PosixLocalEnvProvider; |
| import com.google.devtools.build.lib.profiler.Profiler; |
| import com.google.devtools.build.lib.profiler.SilentCloseable; |
| import com.google.devtools.build.lib.runtime.CommandEnvironment; |
| import com.google.devtools.build.lib.sandbox.SandboxHelpers.SandboxOutputs; |
| import com.google.devtools.build.lib.shell.Command; |
| import com.google.devtools.build.lib.shell.CommandException; |
| import com.google.devtools.build.lib.util.OS; |
| import com.google.devtools.build.lib.vfs.FileSystem; |
| import com.google.devtools.build.lib.vfs.Path; |
| import com.google.devtools.build.lib.vfs.Symlinks; |
| import java.io.File; |
| import java.io.IOException; |
| import java.time.Duration; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.SortedMap; |
| import javax.annotation.Nullable; |
| |
| /** Spawn runner that uses linux sandboxing APIs to execute a local subprocess. */ |
| final class LinuxSandboxedSpawnRunner extends AbstractSandboxSpawnRunner { |
| |
| // Since checking if sandbox is supported is expensive, we remember what we've checked. |
| private static final Map<Path, Boolean> isSupportedMap = new HashMap<>(); |
| |
| /** |
| * Returns whether the linux sandbox is supported on the local machine by running a small command |
| * in it. |
| */ |
| public static boolean isSupported(final CommandEnvironment cmdEnv) { |
| if (OS.getCurrent() != OS.LINUX) { |
| return false; |
| } |
| if (!LinuxSandboxUtil.isSupported(cmdEnv)) { |
| return false; |
| } |
| Path linuxSandbox = LinuxSandboxUtil.getLinuxSandbox(cmdEnv); |
| return isSupportedMap.computeIfAbsent( |
| linuxSandbox, linuxSandboxPath -> computeIsSupported(cmdEnv, linuxSandboxPath)); |
| } |
| |
| private static boolean computeIsSupported(CommandEnvironment cmdEnv, Path linuxSandbox) { |
| ImmutableList<String> linuxSandboxArgv = |
| LinuxSandboxUtil.commandLineBuilder(linuxSandbox, ImmutableList.of("/bin/true")).build(); |
| ImmutableMap<String, String> env = ImmutableMap.of(); |
| Path execRoot = cmdEnv.getExecRoot(); |
| File cwd = execRoot.getPathFile(); |
| |
| Command cmd = new Command(linuxSandboxArgv.toArray(new String[0]), env, cwd); |
| try (SilentCloseable c = Profiler.instance().profile("LinuxSandboxedSpawnRunner.isSupported")) { |
| cmd.execute(ByteStreams.nullOutputStream(), ByteStreams.nullOutputStream()); |
| } catch (CommandException e) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| private final FileSystem fileSystem; |
| private final BlazeDirectories blazeDirs; |
| private final Path execRoot; |
| private final boolean allowNetwork; |
| private final Path linuxSandbox; |
| private final Path sandboxBase; |
| private final Path inaccessibleHelperFile; |
| private final Path inaccessibleHelperDir; |
| private final LocalEnvProvider localEnvProvider; |
| private final Duration timeoutKillDelay; |
| private final @Nullable SandboxfsProcess sandboxfsProcess; |
| private final boolean sandboxfsMapSymlinkTargets; |
| private final TreeDeleter treeDeleter; |
| |
| /** |
| * Creates a sandboxed spawn runner that uses the {@code linux-sandbox} tool. |
| * |
| * @param cmdEnv the command environment to use |
| * @param sandboxBase path to the sandbox base directory |
| * @param inaccessibleHelperFile path to a file that is (already) inaccessible |
| * @param inaccessibleHelperDir path to a directory that is (already) inaccessible |
| * @param timeoutKillDelay an additional grace period before killing timing out commands |
| * @param sandboxfsProcess instance of the sandboxfs process to use; may be null for none, in |
| * which case the runner uses a symlinked sandbox |
| * @param sandboxfsMapSymlinkTargets map the targets of symlinks within the sandbox if true |
| */ |
| LinuxSandboxedSpawnRunner( |
| CommandEnvironment cmdEnv, |
| Path sandboxBase, |
| Path inaccessibleHelperFile, |
| Path inaccessibleHelperDir, |
| Duration timeoutKillDelay, |
| @Nullable SandboxfsProcess sandboxfsProcess, |
| boolean sandboxfsMapSymlinkTargets, |
| TreeDeleter treeDeleter) { |
| super(cmdEnv); |
| this.fileSystem = cmdEnv.getRuntime().getFileSystem(); |
| this.blazeDirs = cmdEnv.getDirectories(); |
| this.execRoot = cmdEnv.getExecRoot(); |
| this.allowNetwork = SandboxHelpers.shouldAllowNetwork(cmdEnv.getOptions()); |
| this.linuxSandbox = LinuxSandboxUtil.getLinuxSandbox(cmdEnv); |
| this.sandboxBase = sandboxBase; |
| this.inaccessibleHelperFile = inaccessibleHelperFile; |
| this.inaccessibleHelperDir = inaccessibleHelperDir; |
| this.timeoutKillDelay = timeoutKillDelay; |
| this.sandboxfsProcess = sandboxfsProcess; |
| this.sandboxfsMapSymlinkTargets = sandboxfsMapSymlinkTargets; |
| this.localEnvProvider = new PosixLocalEnvProvider(cmdEnv.getClientEnv()); |
| this.treeDeleter = treeDeleter; |
| } |
| |
| @Override |
| protected SandboxedSpawn prepareSpawn(Spawn spawn, SpawnExecutionContext context) |
| throws IOException, ExecException { |
| // Each invocation of "exec" gets its own sandbox base. |
| // Note that the value returned by context.getId() is only unique inside one given SpawnRunner, |
| // so we have to prefix our name to turn it into a globally unique value. |
| Path sandboxPath = |
| sandboxBase.getRelative(getName()).getRelative(Integer.toString(context.getId())); |
| sandboxPath.getParentDirectory().createDirectory(); |
| sandboxPath.createDirectory(); |
| |
| // b/64689608: The execroot of the sandboxed process must end with the workspace name, just like |
| // the normal execroot does. |
| Path sandboxExecRoot = sandboxPath.getRelative("execroot").getRelative(execRoot.getBaseName()); |
| sandboxExecRoot.getParentDirectory().createDirectory(); |
| sandboxExecRoot.createDirectory(); |
| |
| ImmutableMap<String, String> environment = |
| localEnvProvider.rewriteLocalEnv(spawn.getEnvironment(), binTools, "/tmp"); |
| |
| ImmutableSet<Path> writableDirs = getWritableDirs(sandboxExecRoot, environment); |
| SandboxOutputs outputs = SandboxHelpers.getOutputs(spawn); |
| Duration timeout = context.getTimeout(); |
| |
| LinuxSandboxUtil.CommandLineBuilder commandLineBuilder = |
| LinuxSandboxUtil.commandLineBuilder(linuxSandbox, spawn.getArguments()) |
| .setWritableFilesAndDirectories(writableDirs) |
| .setTmpfsDirectories(getTmpfsPaths()) |
| .setBindMounts(getReadOnlyBindMounts(blazeDirs, sandboxExecRoot)) |
| .setUseFakeHostname(getSandboxOptions().sandboxFakeHostname) |
| .setCreateNetworkNamespace( |
| !(allowNetwork |
| || Spawns.requiresNetwork( |
| spawn, getSandboxOptions().defaultSandboxAllowNetwork))) |
| .setUseDebugMode(getSandboxOptions().sandboxDebug) |
| .setKillDelay(timeoutKillDelay); |
| |
| if (!timeout.isZero()) { |
| commandLineBuilder.setTimeout(timeout); |
| } |
| |
| if (spawn.getExecutionInfo().containsKey(ExecutionRequirements.REQUIRES_FAKEROOT)) { |
| commandLineBuilder.setUseFakeRoot(true); |
| } else if (getSandboxOptions().sandboxFakeUsername) { |
| commandLineBuilder.setUseFakeUsername(true); |
| } |
| |
| Path statisticsPath = null; |
| if (getSandboxOptions().collectLocalSandboxExecutionStatistics) { |
| statisticsPath = sandboxPath.getRelative("stats.out"); |
| commandLineBuilder.setStatisticsPath(statisticsPath); |
| } |
| |
| if (sandboxfsProcess != null) { |
| return new SandboxfsSandboxedSpawn( |
| sandboxfsProcess, |
| sandboxPath, |
| commandLineBuilder.build(), |
| environment, |
| SandboxHelpers.processInputFiles( |
| spawn, |
| context, |
| execRoot, |
| getSandboxOptions().symlinkedSandboxExpandsTreeArtifactsInRunfilesTree), |
| outputs, |
| ImmutableSet.of(), |
| sandboxfsMapSymlinkTargets, |
| treeDeleter, |
| statisticsPath); |
| } else { |
| return new SymlinkedSandboxedSpawn( |
| sandboxPath, |
| sandboxExecRoot, |
| commandLineBuilder.build(), |
| environment, |
| SandboxHelpers.processInputFiles( |
| spawn, |
| context, |
| execRoot, |
| getSandboxOptions().symlinkedSandboxExpandsTreeArtifactsInRunfilesTree), |
| outputs, |
| writableDirs, |
| treeDeleter, |
| statisticsPath); |
| } |
| } |
| |
| @Override |
| public String getName() { |
| return "linux-sandbox"; |
| } |
| |
| @Override |
| protected ImmutableSet<Path> getWritableDirs(Path sandboxExecRoot, Map<String, String> env) |
| throws IOException { |
| ImmutableSet.Builder<Path> writableDirs = ImmutableSet.builder(); |
| writableDirs.addAll(super.getWritableDirs(sandboxExecRoot, env)); |
| |
| FileSystem fs = sandboxExecRoot.getFileSystem(); |
| writableDirs.add(fs.getPath("/dev/shm").resolveSymbolicLinks()); |
| writableDirs.add(fs.getPath("/tmp")); |
| |
| return writableDirs.build(); |
| } |
| |
| private ImmutableSet<Path> getTmpfsPaths() { |
| ImmutableSet.Builder<Path> tmpfsPaths = ImmutableSet.builder(); |
| for (String tmpfsPath : getSandboxOptions().sandboxTmpfsPath) { |
| tmpfsPaths.add(fileSystem.getPath(tmpfsPath)); |
| } |
| return tmpfsPaths.build(); |
| } |
| |
| private SortedMap<Path, Path> getReadOnlyBindMounts( |
| BlazeDirectories blazeDirs, Path sandboxExecRoot) throws UserExecException { |
| Path tmpPath = fileSystem.getPath("/tmp"); |
| final SortedMap<Path, Path> bindMounts = Maps.newTreeMap(); |
| if (blazeDirs.getWorkspace().startsWith(tmpPath)) { |
| bindMounts.put(blazeDirs.getWorkspace(), blazeDirs.getWorkspace()); |
| } |
| if (blazeDirs.getOutputBase().startsWith(tmpPath)) { |
| bindMounts.put(blazeDirs.getOutputBase(), blazeDirs.getOutputBase()); |
| } |
| for (ImmutableMap.Entry<String, String> additionalMountPath : |
| getSandboxOptions().sandboxAdditionalMounts) { |
| try { |
| final Path mountTarget = fileSystem.getPath(additionalMountPath.getValue()); |
| // If source path is relative, treat it as a relative path inside the execution root |
| final Path mountSource = sandboxExecRoot.getRelative(additionalMountPath.getKey()); |
| // If a target has more than one source path, the latter one will take effect. |
| bindMounts.put(mountTarget, mountSource); |
| } catch (IllegalArgumentException e) { |
| throw new UserExecException( |
| String.format("Error occurred when analyzing bind mount pairs. %s", e.getMessage())); |
| } |
| } |
| for (Path inaccessiblePath : getInaccessiblePaths()) { |
| if (inaccessiblePath.isDirectory(Symlinks.NOFOLLOW)) { |
| bindMounts.put(inaccessiblePath, inaccessibleHelperDir); |
| } else { |
| bindMounts.put(inaccessiblePath, inaccessibleHelperFile); |
| } |
| } |
| validateBindMounts(bindMounts); |
| return bindMounts; |
| } |
| |
| /** |
| * This method does the following things: - If mount source does not exist on the host system, |
| * throw an error message - If mount target exists, check whether the source and target are of the |
| * same type - If mount target does not exist on the host system, throw an error message |
| * |
| * @param bindMounts the bind mounts map with target as key and source as value |
| * @throws UserExecException |
| */ |
| private void validateBindMounts(SortedMap<Path, Path> bindMounts) throws UserExecException { |
| for (SortedMap.Entry<Path, Path> bindMount : bindMounts.entrySet()) { |
| final Path source = bindMount.getValue(); |
| final Path target = bindMount.getKey(); |
| // Mount source should exist in the file system |
| if (!source.exists()) { |
| throw new UserExecException(String.format("Mount source '%s' does not exist.", source)); |
| } |
| // If target exists, but is not of the same type as the source, then we cannot mount it. |
| if (target.exists()) { |
| boolean areBothDirectories = source.isDirectory() && target.isDirectory(); |
| boolean isSourceFile = source.isFile() || source.isSymbolicLink(); |
| boolean isTargetFile = target.isFile() || target.isSymbolicLink(); |
| boolean areBothFiles = isSourceFile && isTargetFile; |
| if (!(areBothDirectories || areBothFiles)) { |
| // Source and target are not of the same type; we cannot mount it. |
| throw new UserExecException( |
| String.format( |
| "Mount target '%s' is not of the same type as mount source '%s'.", |
| target, source)); |
| } |
| } else { |
| // Mount target should exist in the file system |
| throw new UserExecException( |
| String.format( |
| "Mount target '%s' does not exist. Bazel only supports bind mounting on top of " |
| + "existing files/directories. Please create an empty file or directory at " |
| + "the mount target path according to the type of mount source.", |
| target)); |
| } |
| } |
| } |
| |
| @Override |
| public void cleanupSandboxBase(Path sandboxBase, TreeDeleter treeDeleter) throws IOException { |
| // Delete the inaccessible files synchronously, bypassing the treeDeleter. They are only a |
| // couple of files that can be deleted fast, and ensuring they are gone at the end of every |
| // build avoids annoying permission denied errors if the user happens to run "rm -rf" on the |
| // output base. (We have some tests that do that.) |
| if (inaccessibleHelperDir.exists()) { |
| inaccessibleHelperDir.chmod(0700); |
| inaccessibleHelperDir.deleteTree(); |
| } |
| if (inaccessibleHelperFile.exists()) { |
| inaccessibleHelperFile.chmod(0600); |
| inaccessibleHelperFile.delete(); |
| } |
| |
| super.cleanupSandboxBase(sandboxBase, treeDeleter); |
| } |
| } |