// Copyright 2016 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.ImmutableSet;
import com.google.common.eventbus.EventBus;
import com.google.devtools.build.lib.actions.ActionExecutionContext;
import com.google.devtools.build.lib.actions.ActionExecutionMetadata;
import com.google.devtools.build.lib.actions.ActionStatusMessage;
import com.google.devtools.build.lib.actions.ExecException;
import com.google.devtools.build.lib.actions.Executor;
import com.google.devtools.build.lib.actions.ResourceManager;
import com.google.devtools.build.lib.actions.ResourceManager.ResourceHandle;
import com.google.devtools.build.lib.actions.SandboxedSpawnActionContext;
import com.google.devtools.build.lib.actions.Spawn;
import com.google.devtools.build.lib.actions.SpawnActionContext;
import com.google.devtools.build.lib.actions.Spawns;
import com.google.devtools.build.lib.actions.UserExecException;
import com.google.devtools.build.lib.buildtool.BuildRequest;
import com.google.devtools.build.lib.events.Event;
import com.google.devtools.build.lib.events.EventHandler;
import com.google.devtools.build.lib.runtime.CommandEnvironment;
import com.google.devtools.build.lib.util.io.OutErr;
import com.google.devtools.build.lib.vfs.FileSystem;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import java.io.IOException;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicReference;
/** Abstract common ancestor for sandbox strategies implementing the common parts. */
abstract class SandboxStrategy implements SandboxedSpawnActionContext {
private final CommandEnvironment cmdEnv;
private final BuildRequest buildRequest;
private final Path execRoot;
private final Path sandboxBase;
private final boolean verboseFailures;
private final SandboxOptions sandboxOptions;
private final ImmutableSet<Path> inaccessiblePaths;
public SandboxStrategy(
CommandEnvironment cmdEnv,
BuildRequest buildRequest,
Path sandboxBase,
boolean verboseFailures,
SandboxOptions sandboxOptions) {
this.cmdEnv = cmdEnv;
this.buildRequest = buildRequest;
this.execRoot = cmdEnv.getExecRoot();
this.sandboxBase = sandboxBase;
this.verboseFailures = verboseFailures;
this.sandboxOptions = sandboxOptions;
ImmutableSet.Builder<Path> inaccessiblePaths = ImmutableSet.builder();
FileSystem fileSystem = cmdEnv.getDirectories().getFileSystem();
for (String path : sandboxOptions.sandboxBlockPath) {
Path blockedPath = fileSystem.getPath(path);
try {
inaccessiblePaths.add(blockedPath.resolveSymbolicLinks());
} catch (IOException e) {
// It's OK to block access to an invalid symlink. In this case we'll just make the symlink
// itself inaccessible, instead of the target, though.
inaccessiblePaths.add(blockedPath);
}
}
this.inaccessiblePaths = inaccessiblePaths.build();
}
/** Executes the given {@code spawn}. */
@Override
public void exec(Spawn spawn, ActionExecutionContext actionExecutionContext)
throws ExecException, InterruptedException {
exec(spawn, actionExecutionContext, null);
}
@Override
public void exec(
Spawn spawn,
ActionExecutionContext actionExecutionContext,
AtomicReference<Class<? extends SpawnActionContext>> writeOutputFiles)
throws ExecException, InterruptedException {
Executor executor = actionExecutionContext.getExecutor();
// Certain actions can't run remotely or in a sandbox - pass them on to the standalone strategy.
if (!spawn.isRemotable() || spawn.hasNoSandbox()) {
SandboxHelpers.fallbackToNonSandboxedExecution(spawn, actionExecutionContext, executor);
return;
}
EventBus eventBus = actionExecutionContext.getExecutor().getEventBus();
ActionExecutionMetadata owner = spawn.getResourceOwner();
eventBus.post(ActionStatusMessage.schedulingStrategy(owner));
try (ResourceHandle ignored =
ResourceManager.instance().acquireResources(owner, spawn.getLocalResources())) {
actuallyExec(spawn, actionExecutionContext, writeOutputFiles);
} catch (IOException e) {
throw new UserExecException("I/O exception during sandboxed execution", e);
}
}
protected abstract void actuallyExec(
Spawn spawn,
ActionExecutionContext actionExecutionContext,
AtomicReference<Class<? extends SpawnActionContext>> writeOutputFiles)
throws ExecException, InterruptedException, IOException;
protected void runSpawn(
Spawn spawn,
ActionExecutionContext actionExecutionContext,
Map<String, String> spawnEnvironment,
SandboxExecRoot sandboxExecRoot,
Set<PathFragment> outputs,
SandboxRunner runner,
AtomicReference<Class<? extends SpawnActionContext>> writeOutputFiles)
throws ExecException, InterruptedException {
EventHandler eventHandler = actionExecutionContext.getExecutor().getEventHandler();
ExecException execException = null;
OutErr outErr = actionExecutionContext.getFileOutErr();
try {
runner.run(
cmdEnv,
spawn.getArguments(),
spawnEnvironment,
outErr,
Spawns.getTimeoutSeconds(spawn),
SandboxHelpers.shouldAllowNetwork(buildRequest, spawn),
sandboxOptions.sandboxDebug,
sandboxOptions.sandboxFakeHostname,
sandboxOptions.sandboxFakeUsername);
} catch (ExecException e) {
execException = e;
}
if (writeOutputFiles != null && !writeOutputFiles.compareAndSet(null, SandboxStrategy.class)) {
throw new InterruptedException();
}
try {
// We copy the outputs even when the command failed, otherwise StandaloneTestStrategy
// won't be able to get the test logs of a failed test. (We should probably do this in
// some better way.)
sandboxExecRoot.copyOutputs(execRoot, outputs);
} catch (IOException e) {
if (execException == null) {
throw new UserExecException("Could not move output artifacts from sandboxed execution", e);
} else {
// Catch the IOException and turn it into an error message, otherwise this might hide an
// exception thrown during runner.run earlier.
eventHandler.handle(
Event.error(
"I/O exception while extracting output artifacts from sandboxed execution: " + e));
}
}
if (execException != null) {
outErr.printErr(
"Use --strategy="
+ spawn.getMnemonic()
+ "=standalone to disable sandboxing for the failing actions.\n");
throw execException;
}
}
/**
* Returns a temporary directory that should be used as the sandbox directory for a single action.
*/
protected Path getSandboxRoot() throws IOException {
return sandboxBase.getRelative(
java.nio.file.Files.createTempDirectory(
java.nio.file.Paths.get(sandboxBase.getPathString()), "")
.getFileName()
.toString());
}
/**
* Gets the list of directories that the spawn will assume to be writable.
*
* @throws IOException because we might resolve symlinks, which throws {@link IOException}.
*/
protected ImmutableSet<Path> getWritableDirs(Path sandboxExecRoot, Map<String, String> env)
throws IOException {
// We have to make the TEST_TMPDIR directory writable if it is specified.
ImmutableSet.Builder<Path> writablePaths = ImmutableSet.builder();
writablePaths.add(sandboxExecRoot);
if (env.containsKey("TEST_TMPDIR")) {
// We add this even though it may be below sandboxExecRoot (and thus would already be writable
// as a subpath) to take advantage of the side-effect that SymlinkedExecRoot also creates this
// needed directory if it doesn't exist yet.
writablePaths.add(sandboxExecRoot.getRelative(env.get("TEST_TMPDIR")));
}
return writablePaths.build();
}
protected ImmutableSet<Path> getInaccessiblePaths() {
return inaccessiblePaths;
}
@Override
public String toString() {
return "sandboxed";
}
@Override
public boolean shouldPropagateExecException() {
return verboseFailures && sandboxOptions.sandboxDebug;
}
}